technical report metals analysis method for e-liquids€¦ · evap-184-ctr-metals analysis method...

E-Vapour Sub-Group

Technical Report

Metals Analysis Method for

E-Liquids

May 2020

Author and Study Project Leader:

Peter Joza, Labstat International Inc., Canada

Co-Author and Statistical Analysis:

Wendy Wagstaff, Labstat International Inc., Canada

Study Coordinator:

I. Gene Gillman, Enthalpy Analytical LLC, U.S.A.

Table of Contents

1. Introduction ........................................................................................................................ 3

1.1 Study Purpose and Objectives ................................................................................. 3

1.2 Background Information ......................................................................................... 3

2. Organization ....................................................................................................................... 4

2.1 Study Participants .................................................................................................... 4

2.2 Protocol ................................................................................................................... 4

2.3 Directions for Data Analysis ................................................................................... 5

3. Results ................................................................................................................................ 6

3.1 Method Information ................................................................................................ 6

3.2 Outlier Results for Spiked E-Liquid Test Products ................................................. 7

3.3 Summary Statistics (Mean (m̂), Repeatability SD (Sr), Reproducibility SD (SR)) ..... 8

3.4 Individual Participating Laboratory Z-Scores ....................................................... 10

4. Data Representation ......................................................................................................... 14

5. Conclusions ...................................................................................................................... 25

6. Bibliography ..................................................................................................................... 26

Appendix A – List of Participating Laboratories ..................................................................... 27

Appendix B – Experimental Protocol ...................................................................................... 28

Appendix C – Raw Data ........................................................................................................... 33

Appendix D – Mandel’s h and k Graphs for Outlier Identification ......................................... 82

Appendix E – Spiked E-Liquid Test Product Summary Figures ............................................. 92

EVAP-184-CTR-Metals Analysis Method for E-Liquids – May 2020 3/96

1. Introduction

1.1 Study Purpose and Objectives

The purpose of this study was to determine if current in-house methods were sufficient for the

analysis of metals in e-liquids by inductively coupled plasma-mass spectrometry (ICP-MS) or

if a harmonized method may be required.

For this initial proficiency study on methods to determine metals in e-liquids, the ten (10) target

metals for analysis were as follows:

• Arsenic (As) • Cadmium (Cd) • Chromium (Cr) • Copper(Cu) • Iron (Fe)

• Lead (Pb) • Nickel (Ni) • Silver (Ag) • Tin (Sn) • Zinc (Zn)

It was expected that a variety of sample preparation methods would be used by participating

laboratories to prepare the e-liquid test products. The results of this study will be used to

determine if method accuracy is impacted by choice of the preparation (dilution in acid

(aqueous solution) or digestion method). Participating laboratories received eight (8) e-liquid

test products. Four (4) test products that were spiked with known amounts of metals salts.

These samples, along with the corresponding four (4) base test products (unspiked), were tested.

The participating laboratories were required to prepare and analyze the eight (8) e-liquid test

products using their own “in-house” method. This may have involved preparation using

microwave digestion and/or dilution in nitric acid followed by analysis by ICP-MS.

Z-scores were calculated for study participants based on the accuracy of their individual

laboratory data in comparison with the overall study results. Additionally, performance indicators

including the grand means (�̂�), repeatability standard deviations[1] (Sr) and reproducibility

standard deviations[2] (SR) were also determined in accordance with ISO 5725-2.

1.2 Background Information

In May of 2017, the CORESTA E-Vapour Sub-Group (EVAP) commissioned a small group to

investigate the determination of metals in liquids used in E-Vapour products. During the

October 2017 Sub-Group meeting, this small group presented information to the Sub-Group on

methods for the analysis of metals in e-liquids. The group reported that two digestion methods,

microwave digestion and dilution in nitric acid solution, were commonly used for the analysis

of metals. These two methods employed different sample preparation steps and it was not

obvious if one method had advantages over the other. The list of metals included in this study

was selected based on both the current literature [1-4] and elements likely to be present based

on the materials commonly used in the manufacturing of e-vapour devices. The group decided

to conduct a proficiency study, using in-house methods, to determine if a CORESTA

Recommended Method (CRM) could be written for the analysis of metals in e-liquid.

The protocol for the study was approved by the Sub-Group in April 2018. This study was led

by Peter Joza (Labstat). E-liquid samples were supplied by Alternative Ingredients, Inc. and

fortified with the metals of interest by Enthalpy Analytical LLC. The study was originally

planned to run through the Spring of 2018 but extended until September 2018 to allow

additional time for reporting of results.

[1] The standard deviation of test results obtained under repeatability conditions (i.e. successive measurements of

the same measurand carried out under the same conditions of measurement). [2] The standard deviation of test results obtained under reproducibility conditions (i.e. measurements of the same

measurand carried out under changed conditions of measurement).

EVAP-184-CTR Metals Analysis Method for E-Liquids – May 2020 4/96

2. Organization

2.1 Study Participants

In this proficiency test, twelve (12) laboratories took part and all 12 have been included in the

statistical evaluation. Prior to the start of statistical analysis, laboratory codes 1 through 14

(2 labs submitted independent data sets for both sample preparation methods) were assigned by

the study group coordinator, in confidence, to each of the individual sets of data that were

submitted by the participating labs. Appendix A lists the participating laboratories.

2.2 Protocol

Type and number of products tested

4 e-liquids × 2 preparation methods ( unspiked base sample, spiked with known amounts of

metal salts) = 8 e-liquid test products[3], as listed in Table 1. The test products were fortified

with all or some of the target metals in a concentration range between 10-50 µg/mL.

Table 1: E-liquid test products and characteristics

E-Liquid Test Product Code

Flavor Profile Target

Nicotine (%w/w)

Target Propylene

Glycol (%w/w)

Target Glycerin (%w/w)

Target Added H2O

(%w/w)

CS_Metal01_unspiked unflavored 1.5 47 47 0

CS_Metal01_spiked unflavored 1.5 47 47 0

CS_Metal02_unspiked tobacco 1.5 47 47 0

CS_Metal02_spiked tobacco 1.5 47 47 0

CS_Metal03_unspiked tobacco menthol

1.5 47 47 0

CS_Metal03_spiked tobacco menthol

1.5 47 47 0

CS_Metal04_unspiked Fruit/sweet 1.5 47 47 0

CS_Metal04_spiked Fruit/sweet 1.5 47 47 0

Note: for participating labs in locations where the shipment of nicotine-containing products

was an issue, test product formulations without nicotine were shipped and the products had to

be fortified with the amount of nicotine indicated in Table 1 by the participating lab prior to

analysis.

Parameters tested and subjected to statistical analysis

Participating laboratories were requested to follow the protocol “Metals Analysis Method for

E-Liquids” (provided in Appendix B) to analyze the 8 e-liquid test products and to report the

parameters listed in Table 2.

[3] Test products were obtained through Eduardo Berea from Alternative Ingredients Inc.


Table 2: Metals analytes to be reported

Metals Analyte

Number of Replicates

Unit Metals Analyte

Number of Replicates

Unit

Arsenic 4 ng/g Lead 4 ng/g

Cadmium 4 ng/g Nickel 4 ng/g

Chromium 4 ng/g Silver 4 ng/g

Copper 4 ng/g Tin 4 ng/g

Iron 4 ng/g Zinc 4 ng/g

Test Product Storage

Upon receipt, the e-liquid test products were to be refrigerated at approximately 4 °C. Test

products were to be removed from storage a minimum of 2 hours prior to use for analysis. Test

products were not to be opened during the time the samples were equilibrating to ambient

temperature.

Method

The participating laboratories were required to prepare and analyze the e-liquid test products

using their own “in-house” method. This may have involved preparation using microwave

digestion and/or dilution in nitric acid, followed by analysis by ICP-MS.

Note 1: in preparing samples using an “in-house” method, if adjustments to the sample size

were made, the ratio of sample size to acid volume and final volume were to remain constant.

Note 2: if multiple “runs” were required, the paired unspiked and spiked test products for the

same e-liquid were to be analyzed within the same run in order to assess potential background

issues.

Calibration standards were prepared using the “in-house” method for each participating

laboratory. The calibration curve was to have at least 6 levels (including zero) and was to range

from at least 1 ng/mL to 50 ng/mL.

Calibration was to be a linear curve fit through zero and have a R2 ≥ 0.999 for each target metal.

2.3 Directions for Data Analysis

As per the study protocol, statistical analysis was to be conducted in general conformance with

ISO 5725-2:19945 and ISO/TR 22971:2005. Study participants were also to receive Z-scores

for each set of reported results.

However, given the parameters of the study and the actual analytical results submitted by the

participating labs for the test products, the above directions could not be strictly adhered to.

The main study objective was to determine if the various approaches used in the “in-house”

methods of each participating lab, were capable of producing similar results, rather than obtain

a set of consensus data. Therefore, the results submitted by the participating labs were audited

for the identification of outliers as per ISO 5725-2:1994.

As such, the identification of outliers using the methods discussed in ISO 5725-2:1994 was still

employed, but the criteria for the actual removal of outliers was based only on the Mandel’s h

and k statistics, with plots provided to give labs a visual way of comparing their data with that

of other labs.


Consideration of Sample Preparation Method

Also discussed in the study purpose was the use of different sample preparation methods, such

as sample digestion and sample dilution. As participating labs submitted data using one or both

of these techniques, the data was divided by sample preparation method (digestion, dilution)

prior to data summarization.

Statistical Analysis of unspiked Test Product Results

The test products that were subjected to metals analysis included both spiked and unspiked

e-liquids. The expectation was that none of the tested metals should be found in the unspiked

test products, and if a quantifiable amount of a metal was found by a participating lab, it is

likely to be an indicator of contamination or some other process issue. So, the identification of

these unexpected results in the unspiked test products was required, but the full statistical

analysis of the unspiked test product results was not required since the expectation was for the

results to be unquantifiable.

Statistical Analysis of Spiked Test Product Results

For the test products that were spiked with metal salts, the identification and removal of outliers

(as discussed above) was employed and test results were summarized across all participating

labs by (1) sample preparation method (digestion, dilution), (2) metals analyte and (3) e-liquid

sample number (CS_Metal01, CS_Metal02, CS_Metal03, CS_Metal04). The summarization

of results included the calculation of the general mean (�̂�), the repeatability standard deviation

(Sr) and the reproducibility standard deviation (SR).

Additionally, the mean result (�̅�) of each metals analyte reported by each participating lab for

each spiked e-liquid test product, was determined. The results were compared to the

corresponding general mean (�̂�) and reproducibility standard deviation (SR) of each sample

preparation method, by means of a Z-score calculation ([�̅� − �̂�] ÷ 𝑆𝑅) to give each

participating lab an idea as to how far removed their own results were from the collective results

of all participating labs.

Note: In general, results that were lower than the reported limit of quantification (LOQ) were

excluded from statistical analysis, with the exception of some results for iron and zinc reported

by labs 5 and 13, which had results that were comparable to those submitted by other labs but

were technically lower than the LOQ reported by the individual labs.

3. Results

3.1 Method Information

As per the study protocol, each participating lab used their own “in-house” method for the

preparation and analysis of the e-liquid test products. Therefore, the data reporting templates

distributed to each lab, included requests for information on the individual methods employed

by each lab. The method information provided by each participating lab is summarized in

Appendix C, consisting of the information in Table 3.


Table 3: Method details reported by each participating lab

Item Number

General Method Information Method Details (by Analyte)

1 Sample Preparation Type Analyte

2 Digestion Type and Vessel Size Mass

3 Acid Type(S) and Volume(S) Internal Standard (IS)

4 Sample Size (Grams) IS Concentration [ng/mL]

5 Final Volume (Ml) Analysis Mode

6 Solution Sample Matrices Reaction Gas Used

7 Make/Model of ICP-MS Standard Level(s)

8 - Low Standard Conc. [ng/mL]

9 - High Standard Conc. [ng/mL]

10 - Limit of Detection (LOD) [ng/g]

11 - Limit of Quantitation (LOQ) [ng/g]

3.2 Outlier Results for Spiked E-Liquid Test Products

The main objective was to determine if the various “in-house” methods of each participating

lab, were capable of producing similar results, rather than obtain a set of consensus data.

Therefore, the outlier analysis was less formal than would be required with a true proficiency

study. In accordance with ISO 5725-2:1994, outlying labs were identified using the Mandel’s

h and k graphical consistency techniques for identification of outliers in means and variances,

respectively, over numerical outlier tests such as Grubbs’ and Cochran’s. The graphical

consistency figures for Mandel’s h and k statistics are included in Appendix D. Labs with

potentially significant (α = 0.01) Mandel’s h and k statistics are denoted in Table 4 below.

Table 4: List of potential outliers (α = 0.01) for spiked e-liquid test product means and

standard deviations

Metals Analyte

CS_Metal01 Spiked

CS_Metal02 Spiked

CS_Metal03 Spiked

CS_Metal04 Spiked

Mean (h) SD (k) Mean (h) SD (k) Mean (h) SD (k) Mean (h) SD (k)

Arsenic 11 - 11 - 11 - 11 13

Cadmium - - - 7 - -

Chromium - 13 - 10 - 4 - 7

Copper 5 5 11 5 5 5 5 5

Iron - 13 - 1 11 1 1 1

Lead 11 - 11 - 11 12 11 4

Nickel - - - 8 - - - 1

Silver 5 2 5 12 5 2 5 -

Tin - 8 - 8 - 8 - 8

Zinc - 13 - 5, 13 - 13 - 5, 13


Table 5 lists the laboratories which were rejected for inclusion in the overall summary statistics

for each (1) sample preparation method (digestion, dilution), (2) metals analyte and (3) spiked

e-liquid sample number (CS_Metal01, CS_Metal02, CS_Metal03, CS_Metal04) and the

corresponding reason for their exclusion. A total of 4 participating laboratories (5, 7, 11, 12)

were rejected at least once for either one spiked e-liquid test product or one metals analyte.

Table 5: List of excluded labs for spiked e-liquid test product summary statistics

Metals

Analyte

CS_Metal01 Spiked

CS_Metal02 Spiked

CS_Metal03 Spiked

CS_Metal04 Spiked

Excluded Reason Excluded Reason Excluded Reason Excluded Reason

Arsenic 11 outlier 11 outlier 11 outlier 11 outlier

Copper 11 NQ 11 outlier 11 NQ 11 NQ

12 NQ 12 NQ 12 NQ 12 NQ

Silver 5 outlier 5 outlier 5 outlier 5 outlier

Zinc 11 NQ - - 11 NQ 7 NQ

12 NQ 12 NQ 12 NQ 12 NQ

NQ: not quantifiable (< LOQ)

Questionable Results for Unspiked E-Liquid Test Products

A formal evaluation of outliers was not performed for the unspiked e-liquid test product results

due to the fact that the tested metals analytes were expected to be undetectable in these samples.

However, there were some reported results in the unspiked e-liquid test products that were

unexpected and are highlighted in Table 6 below (and in the raw data plots in section 3.4 of this

report) for possible review by the participating labs who provided the results.

Table 6: List of questionable results for unspiked e-liquid test products

Metals Analyte

CS_Metal01 Unspiked

CS_Metal02 Unspiked

CS_Metal03 Unspiked

CS_Metal04 Unspiked

Lab # Mean (ng/g)

Lab # Mean (ng/g)

Lab # Mean (ng/g)

Lab # Mean (ng/g)

Chromium 7 240 - - - - - -

Copper - - 11 1147 - - - -

Iron - - 11 9744 - - 11 58332

Lead - - 11 119 - - - -

Zinc - - 11 1748 - - 11 1470

3.3 Summary Statistics (Mean (�̂�), Repeatability SD (Sr), Reproducibility SD (SR))

The repeatability and reproducibility standard deviations (Sr, SR) are used to characterize the

precision of a single test method. In this study, the various “in-house” analytical methods used

two fundamentally different preparative techniques; digestion and dilution. The aggregate

study data was divided into these subsets. The repeatability and reproducibility standard

deviations (Sr, SR) were calculated for each (1) sample preparation method (digestion,

dilution), (2) metals analyte and (3) spiked e-liquid test product (CS_Metal01, CS_Metal02,

CS_Metal03, CS_Metal04) after removal of outliers (see section 3.2). The results are

summarized in Table 7 and the corresponding figures are given in Appendix E.

EVAP-184-CTR-Metals Analysis Method for E-Liquids - May 2020 9/96

Table 7: Spiked e-liquid test product summary statistics (number of labs (N), mean (�̂�), repeatability SD (Sr), reproducibility SD (SR))

Metals Preparation Unit

CS_Metal01 Spiked CS_Metal02 Spiked CS_Metal03 Spiked CS_Metal04 Spiked

Analyte Method N �̂� Sr SR N �̂� Sr SR N �̂� Sr SR N �̂� Sr SR

Arsenic Digestion ng/g 7 541.4 16.0 68.3 7 546.2 20.0 99.1 7 541.9 14.2 73.1 7 533.0 42.1 64.0

Arsenic Dilution ng/g 6 463.4 16.4 56.0 6 449.2 11.0 58.6 6 454.1 5.8 54.7 6 454.2 7.6 61.1

Cadmium Digestion ng/g 8 487.5 12.0 37.1 8 483.7 22.6 54.6 8 478.3 10.8 38.3 8 486.4 10.8 34.4

Cadmium Dilution ng/g 6 492.8 12.3 22.1 6 489.1 6.5 21.1 6 494.6 7.3 15.2 6 491.3 10.4 25.1

Chromium Digestion ng/g 8 521.5 24.5 70.0 8 516.9 16.8 73.9 8 527.3 26.1 84.2 8 510.2 20.1 63.0

Chromium Dilution ng/g 6 487.6 18.3 44.3 6 484.4 18.0 38.9 6 490.4 14.4 31.7 6 485.9 10.8 40.3

Copper Digestion ng/g 6 541.8 55.9 99.2 6 514.6 24.9 74.7 6 554.1 48.2 126.1 6 539.5 17.0 109.2

Copper Dilution ng/g 5 496.7 14.0 30.4 5 490.2 13.4 26.5 5 491.1 7.4 23.7 5 496.8 13.8 31.7

Iron Digestion ng/g 6 711.1 101.3 190.7 6 671.8 56.6 126.2 6 730.0 91.2 199.4 6 693.3 174.5 205.6

Iron Dilution ng/g 6 592.3 32.6 58.0 6 612.0 29.0 35.1 6 652.2 50.0 65.3 6 603.3 26.2 50.4

Lead Digestion ng/g 8 505.6 17.8 63.6 8 506.6 13.2 71.2 8 506.7 9.1 61.9 8 512.2 13.9 71.9

Lead Dilution ng/g 6 504.2 10.7 42.2 6 504.9 7.6 41.3 6 504.7 9.8 44.2 6 507.0 11.2 42.5

Nickel Digestion ng/g 8 509.1 18.4 22.6 8 501.1 11.9 25.8 8 502.8 10.3 21.1 8 507.7 37.7 40.8

Nickel Dilution ng/g 6 490.0 14.1 35.9 6 486.6 15.5 31.0 6 490.6 9.6 26.9 6 490.2 8.5 30.2

Silver Digestion ng/g 4 494.4 23.9 54.9 4 424.6 15.1 56.6 4 488.8 14.1 47.3 4 465.6 15.2 37.2

Silver Dilution ng/g 6 485.9 14.3 28.0 6 434.9 14.8 72.0 6 473.2 10.3 38.7 6 466.6 8.3 42.4

Tin Digestion ng/g 5 495.4 10.6 37.4 5 488.9 7.8 46.3 5 489.9 8.4 44.8 5 494.0 12.7 42.0

Tin Dilution ng/g 6 496.7 12.5 33.7 6 499.6 13.5 32.6 6 488.4 15.5 21.6 6 487.6 12.2 20.4

Zinc Digestion ng/g 5 606.0 55.2 272.2 6 636.9 32.4 293.2 5 556.3 48.5 225.2 5 720.5 39.2 247.1

Zinc Dilution ng/g 5 507.4 18.0 24.5 5 506.1 13.2 13.7 5 513.1 12.4 16.2 5 514.4 9.8 22.6


3.4 Individual Participating Laboratory Z-Scores

Individual z-scores were calculated for each set of spiked e-liquid test product results provided

by each participating laboratory by comparing the spiked e-liquid test product mean (�̅�) to the

general mean (�̂�) and reproducibility standard deviation (SR) (as given in Table 7), where

z-score = ([�̅� − �̂�] ÷ 𝑆𝑅). The z-score results are summarized in Table 8.

Table 8: Spiked e-liquid test product z-scores for each participating laboratory

Lab Analyte Sample Spiked Sample Z-Score Statistician

ID Name Prep. CS_Metal01 CS_Metal02 CS_Metal03 CS_Metal04 Comments

1 Arsenic Digestion -0.784 -0.660 -0.949 -0.768

1 Cadmium Digestion -0.006 0.136 0.156 0.047

1 Chromium Digestion -0.325 -0.238 -0.340 -0.155

1 Copper Digestion -0.499 -0.276 -0.520 -0.393

1 Iron Digestion 0.027 0.940 0.156 1.047

1 Lead Digestion 0.271 0.201 0.149 0.117

1 Nickel Digestion -0.315 0.250 0.191 -1.133

1 Tin Digestion -0.103 0.062 -0.027 -0.089

1 Zinc Digestion -0.521 -0.592 -0.467 -1.041


2 Cadmium Digestion -1.066 -1.502 -1.320 -1.122



2 Iron Digestion -0.796 -0.949 -0.878 -0.665

2 Lead Digestion -1.131 -1.308 -1.504 -1.197

2 Nickel Digestion -1.404 -2.232 -2.012 -0.460

2 Silver Digestion 0.981 0.780 1.135 -0.298

2 Tin Digestion -1.045 -1.389 -1.252 -1.124

3 Arsenic Dilution -0.419 -0.537 -0.646 -0.547

3 Cadmium Dilution 1.401 1.685 1.806 1.302

3 Chromium Dilution 1.098 1.072 1.076 1.183

3 Copper Dilution 1.151 1.189 1.274 0.891

3 Iron Dilution 0.818 0.967 -0.011 0.847

3 Lead Dilution 0.345 0.335 0.155 0.371

3 Nickel Dilution 1.371 1.465 1.515 1.575

3 Silver Dilution 1.369 1.114 1.255 1.283

3 Tin Dilution 0.491 0.364 0.929 1.039

3 Zinc Dilution 0.207 0.154 -0.439 -0.184


4 Cadmium Digestion 0.788 0.528 0.345 0.607

4 Chromium Digestion 0.068 0.711 1.211 0.786




4 Lead Digestion -0.678 -0.440 -0.141 -0.323

4 Nickel Digestion 0.230 0.033 0.719 -0.018

5 Arsenic Digestion 0.162 0.053 0.060 0.493

5 Cadmium Digestion -0.047 -0.084 -0.179 0.114

5 Chromium Digestion 0.439 -0.014 -0.213 0.007

5 Copper Digestion 1.442 1.510 1.734 1.925

5 Iron Digestion 1.190 0.211 0.040 -0.044

5 Lead Digestion -0.111 -0.192 -0.156 -0.159

5 Nickel Digestion 0.967 0.395 0.624 0.444

5 Silver Digestion - - - -10.710

Samples not quantifiable, CS_Metal04

Low Lab Mean

(Excluded)

5 Tin Digestion 1.564 1.378 1.468 1.458

5 Zinc Digestion 0.695 0.146 0.771 0.604

6 Arsenic Dilution 0.163 0.242 0.082 0.143

6 Cadmium Dilution -0.181 -0.170 -0.210 -0.054


6 Copper Dilution 0.326 0.589 0.639 0.929

6 Iron Dilution 0.518 -0.137 -0.688 0.103

6 Lead Dilution -0.471 -0.581 -0.486 -0.552

6 Nickel Dilution 0.430 0.505 0.464 0.466

6 Silver Dilution 0.163 0.762 0.488 0.663

6 Tin Dilution -0.560 -0.581 -0.327 -0.322

6 Zinc Dilution -0.242 -0.082 -0.692 -0.435

7 Arsenic Digestion 0.017 1.494 0.325 -0.236



7 Copper Digestion 0.622 0.516 0.283 0.013

7 Iron Digestion -0.873 -1.163 -0.944 -0.692

7 Lead Digestion 0.537 0.241 0.351 0.400

7 Nickel Digestion -0.140 0.631 0.449 -0.176

7 Silver Digestion 0.395 0.827 0.378 1.372

7 Zinc Digestion -1.105 -1.220 -1.147 - CS_Metal04

not

quantifiable


8 Cadmium Dilution 0.609 0.393 -0.055 0.899




8 Chromium Dilution 0.428 -0.210 -0.086 0.049

8 Copper Dilution 0.196 -0.567 -0.521 -0.168

8 Iron Dilution -0.211 -1.163 -0.739 -0.546

8 Lead Dilution 0.164 -0.041 -0.146 0.299

8 Nickel Dilution 0.492 0.072 0.337 0.274

8 Silver Dilution 0.531 -0.288 -1.067 -1.270

8 Tin Dilution 1.454 1.575 -0.391 -0.156

8 Zinc Dilution 1.225 0.596 1.230 1.633





9 Lead Digestion -0.189 0.140 0.160 -0.098


9 Zinc Digestion -0.391 -0.536 -0.408 -1.074



10 Chromium Dilution -0.519 -0.283 -0.782 -0.562

10 Copper Dilution -0.339 -0.151 -0.230 -0.389

10 Iron Dilution 0.753 0.363 -0.266 0.733

10 Lead Dilution -0.597 -0.592 -0.574 -0.656

10 Nickel Dilution -0.369 -0.360 -0.541 -0.490

10 Silver Dilution -0.237 0.652 -0.870 0.081

10 Tin Dilution -0.143 -0.206 0.100 0.156

10 Zinc Dilution -0.417 -0.883 -0.199 -0.373


All Samples have Low Lab Mean (Excluded)

11 Cadmium Digestion -1.721 -1.205 -1.461 -1.673


11 Copper Digestion - 7.019 - -

Samples not quantifiable, CS_Metal02

High Lab Mean

(Excluded)

11 Iron Digestion -0.491 -0.068 1.590 -0.153

11 Lead Digestion 1.991 2.064 1.941 2.090

11 Nickel Digestion -0.024 0.344 -0.572 0.779

11 Silver Digestion -1.193 -0.447 -1.091 -0.340




11 Tin Digestion 0.041 0.180 0.181 0.264

11 Zinc Digestion - 1.538 - 1.058

CS_Metal01 and

CS_Metal03 not

quantifiable

12 Arsenic Dilution -1.606 -1.728 -1.610 -1.649


12 Chromium Dilution -1.588 -1.562 -1.329 -1.604

12 Copper Dilution - - - - All Samples

not quantifiable

12 Iron Dilution -1.440 0.020 1.214 -1.511

12 Lead Dilution 1.671 1.797 1.877 1.617

12 Nickel Dilution -1.218 -1.077 -1.018 -1.023

12 Silver Dilution -0.677 -1.066 0.807 0.280

12 Tin Dilution 0.093 0.015 0.811 0.682

12 Zinc Dilution - - - - All Samples

not quantifiable



13 Chromium Digestion 0.483 0.189 -0.087 0.251

13 Copper Digestion -0.110 0.047 -0.130 -0.116

13 Iron Digestion 0.943 1.029 0.035 0.507

13 Lead Digestion -0.689 -0.706 -0.800 -0.830


13 Silver Digestion -0.183 -1.161 -0.423 -0.734

13 Tin Digestion -0.457 -0.231 -0.370 -0.510

13 Zinc Digestion 1.322 0.665 1.252 0.453




14 Copper Dilution -1.333 -1.061 -1.161 -1.263

14 Iron Dilution -0.438 -0.049 0.489 0.373

14 Lead Dilution -1.113 -0.918 -0.826 -1.077

14 Nickel Dilution -0.705 -0.605 -0.756 -0.802

14 Silver Dilution -1.150 -1.173 -0.613 -1.037

14 Tin Dilution -1.336 -1.166 -1.123 -1.398

14 Zinc Dilution -0.773 0.215 0.100 -0.641


4. Data Representation

As an illustration of the type of data representation expected, the Figures 1a through 10b show

the raw data for all 8 e-liquid test products for each of 10 metals analytes, with separate figures

for each metals analyte and e-liquid test product spiking status (spiked or unspiked). Labs

included in each figure are further divided by sample preparation method, with digestion

method results denoted in black and dilution method results denoted in grey. Laboratories

excluded from summary statistic calculations are identified in red (digestion method) and pink

(dilution method). The corresponding limit of quantification (LOQ) applicable to each set of

plotted replicate results is denoted by a blue column series.

Appendix C contains the raw data (replicates) for every measured parameter included in the

study, along with basic statistics (mean and standard deviation) for each metals analyte reported

for each e-liquid test product.


Figure 1a: Arsenic [ng/g] in spiked e-liquid test products

Note: Lab 11 (all test products) was excluded from all spiked e-liquid test product summary statistics due to outlying lab means.

Figure 1b: Arsenic [ng/g] in unspiked e-liquid test products


Figure 2a: Cadmium [ng/g] in spiked e-liquid test products

Figure 2b: Cadmium [ng/g] in unspiked e-liquid test products


Figure 3a: Chromium [ng/g] in spiked e-liquid test products

Figure 3b: Chromium [ng/g] in unspiked e-liquid test products

Note: Lab 7 (CS_Metal01) unspiked e-liquid test product results are quantifiable and appear to be higher than other participating labs.


Figure 4a: Copper [ng/g] in spiked e-liquid test products

Note: Lab 11 and Lab 12 (all test products) were excluded from all spiked e-liquid test product summary statistics due to identified mean outliers

and reporting of non-quantifiable results.

Figure 4b: Copper [ng/g] in unspiked e-liquid test products



Figure 5a: iron [ng/g] in spiked e-liquid test products

Figure 5b: Iron [ng/g] in unspiked e-liquid test products

Note: Lab 11 (CS_Metal02, CS_Metal04) unspiked e-liquid test product results have very high reported results (> 10,000 ng/g).


Figure 6a: Lead [ng/g] in spiked e-liquid test products

Figure 6b: Lead [ng/g] in unspiked e-liquid test products



Figure 7a: Nickel [ng/g] in spiked e-liquid test products

Figure 7b: Nickel [ng/g] in unspiked e-liquid test products


Figure 8a: Silver [ng/g] in spiked e-liquid test products

Note: Lab 5 (all test products) was excluded from all spiked e-liquid test product summary statistics due to identified mean outliers.

Figure 8b: Silver [ng/g] in unspiked e-liquid test products


Figure 9a: Tin [ng/g] in spiked e-liquid test products

Figure 9b: Tin [ng/g] in unspiked e-liquid test products


Figure 10a: Zinc [ng/g] in spiked e-liquid test products

Note: Lab 12 (all test products), Lab 11 (CS_Metal01, CS_Metal03) and Lab 7 (CS_Metal04) were excluded from all spiked e-liquid test product

summary statistics due to reporting of non-quantifiable results.

Figure 10b: Zinc [ng/g] in unspiked e-liquid test products

Note: Lab 11 (CS_Metal02, CS_Metal04) unspiked e-liquid test product results are quantifiable and appear to be higher than other participating labs.


5. Conclusions

Of the 14 sets of results that were submitted by the 12 participating labs, 8 used the digestion

method and 6 used the dilution method, so there was fair representation of both sample

preparation methods within the reported data.

For the unspiked e-liquid test products, the majority of results were not quantifiable as reported

by the individual labs, however, there were some specific results identified within the report

that should be looked at in further detail by the participating labs who submitted the data since

the results are quantifiable and also far exceed the results reported by other participating labs,

so these labs may have some process issues that were not identified.

For the spiked e-liquid test products, there were some non-quantifiable results for both copper

and zinc that had to be excluded from statistical analysis, so labs that submitted these non-

quantifiable results should try to determine why they were not able to quantify these analytes

when other labs could. Additionally, a couple of labs had iron and zinc results that were

comparable to those of other labs, but were technically identified as non-quantifiable due to

LOD/LOQ values that were much higher than other participating labs.

For spiked e-liquid test product results that were specifically identified as outliers, there was

essentially one (1) lab which had low arsenic means and one (1) lab which had low silver means.

The data of the spiked e-liquid test product results was summarized by; (1) metals analyte,

(2) sample preparation method and (3) sample number. Based on the calculated general means

and standard deviations (Sr, SR), the repeatability and reproducibility variances obtained using

the dilution method are, in general, equivalent to or smaller than those obtained using the

digestion method. The evidence of this seems fairly strong, since each set of combined lab data

contains comparable numbers of labs (within 2) for the 2 sample preparation methods.

For arsenic (and, to a lesser extent, zinc), the mean result obtained with the dilution method is

lower than that obtained with the digestion method for all 4 spiked e-liquid test products. The

bias of the Arsenic results generated by the dilution techniques is about 15 % lower than the

results generated by the digestion technique. However, based on the target spike (fortification)

amount of 500 ng/g, the accuracy, using the calculated mean for each of the four (4) spiked

samples, is similar between the two (see Table 7). It is more difficult to determine if there is a

true accuracy bias for Zinc using the digestion technique. The higher calculated mean for each

of the four (4) spiked samples may be influenced by the poorer reproducibility of the digestion

technique.

The above observations were further confirmed with a formal statistical analysis of variance

(ANOVA) for each metal and demonstrated the significance (α=0.05) of the sample preparation

technique (digestion vs. dilution) for arsenic and zinc. The results that were not significantly

impacted by technique were lead, silver and tin. The formal comparison of the techniques also

indicated that in all instances where the sample preparation technique was significant, results

obtained using dilution were lower than those obtained using digestion.

Additionally, statistical analysis identified issues of heterogeneity of variance with zinc, and to

a lesser extent, iron, copper, chromium and cadmium. In each of these cases, the lab-to-lab

variance obtained using the dilution technique was lower than that obtained using the digestion

technique. As such, formal ANOVA comparisons of the sample preparation techniques could

not be appropriately applied for these metals.


The above findings would have to be taken into account in any further decisions regarding

preference of one technique over another. The question that still needs to be answered is

whether the significant differences in mean metals results, and lab-to-lab variance between the

two techniques, are important in regards to which technique to apply.

The data suggests that either technique (digestion or dilution) could be used for the

determination of metals in e-liquid. However, the data also suggests that results may differ

based on the technique used and specific attention to detail, to reduce potential sources of

background contamination, is necessary regardless of the technique used. Quantification, for

some metals, may be impacted by matrix effects and must be thoroughly investigated when

validating any method. The various instrument parameters used in this study (Appendix C

sections 1 and 2), with respect to the internal standard used and instrument mode, have proven

to be adequate for selectivity and quantification. However, additional instrument parameters

may be necessary to ensure data quality.

Based on the simpler sample preparation and equivalency of the study results, the EVAP Sub-

Group decided to plan a future collaborative study using only the dilution method. The goal of

this collaborative study would be to produce a CORESTA Recommend Method for the analysis

of metals in e-liquids.

6. Bibliography

1) Tayyarah R, Long GA. Comparison of select analytes in aerosol from e-cigarettes with

smoke from conventional cigarettes and with ambient air. Regul Toxicol Pharmacol.

2014;70(3):704-710.

2) Ohashi S. Development and Validation of an ICP-MS Method for Simultaneous

Determination of Selected Metals in Electronic Cigarette Aerosol. Beiträge zur

Tabakforschung International/Contributions to Tobacco Research. 2018;28(1):2-13.

3) Goniewicz ML, Knysak J, Gawron M, et al. Levels of selected carcinogens and toxicants

in vapour from electronic cigarettes. Tob Control. 2014;23(2):133-139.

4) Williams M, Villarreal A, Bozhilov K, Lin S, Talbot P. Metal and silicate particles

including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol.

PLoS One. 2013;8(3):e57987.

5) ISO 5725-2:1994, Accuracy (trueness and precision) of measurement method and results

– Part 2: Basic method for the determination of repeatability and reproducibility of a

standard measurement method.


Appendix A – List of Participating Laboratories

Participating Laboratory Contact Person Contact E-Mail

China Tobacco Zhejiang Industrial Co., Ltd. XIA, Qian

Enthalpy Analytical Gene Gillman

JT-Aobadai

Hideki Nagae

Teruo Nishi

Akihito Shimazu

JTI Oekolab Dr. Ernst Schmeisser

Dr. Herwig Stepan

KT&G Research Institute Jeongmin Lee

Laboratoire Nationale de Métrologie et d'Essai Laurent Dutertre

Labstat International ULC Peter Joza

Wendy Wagstaff

Philip Morris International- R&D Soazig Le Bouhellec

RJ Reynolds Tobacco Co. Randy Weidman

Souza Cruz - BAT Brazil Alexandre Paprocki

VR Analytical Lori Reed

Zhengzhou Tobacco Research Institute of CNTC Huapeng Cui


Appendix B – Experimental Protocol

Study Protocol

CORESTA E-VAPOUR SUB-GROUP

Project Number: 184

Project Title: Metals Analysis Method for E-Liquids

Type of Document: Protocol

Revision Date: May 18, 2018

Written by: Lori Reed (VR Analytical), Peter Joza (Labstat International ULC) and I. Gene

Gilman (Enthalpy Analytical, SG Secretary)


1. Introduction

This protocol describes the initial proficiency study on methods to determine metals in

e-liquids. The target metals for analysis are listed below.

• Arsenic (As) • Iron (Fe) • Tin (Sn)

• Cadmium (Cd) • Lead (Pb) • Zinc (Zn)

• Chromium (Cr) • Nickel (Ni)

• Copper (Cu) • Silver (Ag)

2. Objective

The objective of this study is to determine if current in-house methods are sufficient for the

analysis of metals in e-liquids by inductively coupled plasma-mass spectrometry (ICP-MS) or

if a harmonized method is required. It is expected that a variety of sample digestion methods

will be used to prepare the study samples. The results of this study will be used to determine if

method accuracy is impacted by choice of the preparatory or digestion method. Participating

laboratories will receive eight (8) e-liquid samples. Four (4) samples that have been spiked

with known amounts of metal salts, and the corresponding four (4) base samples (unspiked).

The laboratories will need to prepare and analyse the e-liquid samples using their own “in-

house method”. This may involve preparation using microwave digestion and/or dilution in

nitric acid and then analysis by ICP-MS. Study participates will receive “Z” scores based on

study results and accuracy of their data.

3. Time Schedule and Data Reporting

The time schedule in Table 1 will allow for tabulation of the results, completion of the statistical

analysis, and presentation at the 2018 Fall EVAP meeting which is scheduled for October 2018

in Kunming, China

Table 1. Time Schedule and Data Reporting Table

Date Activity

March, 2018 Distribute draft protocol and data reporting sheet

March, 2018 Laboratories state their intention to participate and order supplies

March, 2018 Distribute final protocol and data reporting sheet

April – May, 2018 Participants order and receive the samples

May – June, 2018 Laboratories conduct the study

July 15, 2018 Laboratories submit results by this date

July 2018 Statistical evaluation and preparation of results

October, 2018 Discuss results at 2018 Fall EVAP meeting


4. Participating Laboratories

Following receipt of this protocol, the participating laboratories (Table 2) in this study will

confirm or notify Peter Joza and Gene Gillman of their active participation.

Table 2. Participating Laboratories Table

Participating Laboratories

KT&G

JTI ÖKOLAB

JT-Aobadai

China Tobacco Zhejiang Industrial

PMI R&D

Souza Cruz

Labstat

Enthalpy Analytical

VR Analytical

RJR

LNE French Metrology

5. Samples

5.1 Selection

Each participating laboratory should request the following e-liquid products and quantities

stated in Table 3. The samples will be fortified with all or some of the target metals in a

concentration range between 10-50 µg/mL by the supplier.

Table 3. 2018 CORESTA Metals Study Products

Sample ID Flavor Profile Target

Nicotine (%w/w)

Target Propylene

Glycol (%w/w)

Target Glycerin (%w/w)

Target Added

H2O (%w/w)

CS_Metal01_ unspiked unflavored 1.5 47 47 0

CS_Metal01_spiked unflavored 1.5 47 47 0

CS_Metal02_ unspiked tobacco 1.5 47 47 0

CS_Metal02_spiked tobacco 1.5 47 47 0

CS_Metal03_ unspiked tobacco menthol 1.5 47 47 0

CS_Metal03_spiked tobacco menthol 1.5 47 47 0

CS_Metal04_ unspiked Fruit/sweet 1.5 47 47 0

CS_Metal04_spiked Fruit/sweet 1.5 47 47 0


5.2 E-Liquid Supply and Shipping

Shipments of the 2018 Metals Collaborative Study products may be obtained through Eduardo

Berea from Alternative Ingredients Inc. Product versions have also been formulated that do not

contain nicotine. Please request these if shipping nicotine containing products is a problem in

your location. Please fortify the products with the indicated amount of nicotine prior to

analysis.

Each participating laboratory will send its shipping address, person to whom delivery should

be made, shipping account (FedEx International, DHS, UPS) arrangements, and any special

delivery information to the following email address: xxxxxxxxx

Eduardo Berea will inform the laboratories of the actual shipping date and tracking information

so that the receiving laboratories can prepare for receipt of the samples. Samples will be

shipped at ambient conditions. Laboratories should not submit data if they question the

integrity of the samples they received.

5.3 Receipt

Upon receipt, the samples must immediately be stored at approximately 4 °C.

5.4 Within Laboratory Sample Preparation

Samples should be removed from the refrigerator a minimum of 2 hours prior to opening for

analysis. The samples should not be opened during the time the samples are equilibrating to

ambient temperature.

6. Sample Preparation

Samples preparation should be performed using the participant’s “in-house method”. When

preparing samples, if adjustments to the sample size are required, the final volume should

remain constant. Should this be required for a specific sample (treated differently from the

others), a note should be added in the “General Information” worksheet regarding “Were there

any difficulties in performing the analysis?” section. The change in sample size will impact the

LOD and LOQ for that sample.

Four (4) replicates are to be reported per sample. If multiple “runs” are required, ensure the

“unspiked” and “spiked” (paired) samples are analyzed within the same run in order to assess

potential background issues.

Note: If the lab is able to perform multiple procedures/techniques (e.g. dilution and

digestion) both sets of data may be reported. The data from the alternative technique must

be reported as an independent data set and will be processed accordingly (i.e. Lab 1a, Lab

1b, etc.).


7. Standard Preparation

Calibration standards should be prepared using the participant’s “in-house method”. The

calibration curve must have at least 6 levels (including zero) and should range from at least

1 ng/mL to 50 ng/mL.

8. Analysis

Analysis should be prepared using the participant’s “in-house method”. Calibration should be

a linear curve fit through zero and have a R2 0.999 for each target metal.

9. Data Reporting

Enter the final results and any comments into the provided data reporting spreadsheet

(E-Liquid_Metals_Data Reporting Sheet_Final_2018). The final reporting spreadsheet and any

questions should be forwarded to the study coordinator:

• Data shall be reported without altering the format in the data sheets

• The worksheet requires the LOD and LOQ be reported for each element.

o If data are below a quantitation limit, report the estimated (numeric) analytical

result for the specific metal. Any data between the LOD and LOQ will be

handled appropriately in the statistical analysis.

o If data are below a detection limit, report the (numeric/artificial) result for the

specific metal. Any data below the LOD will be handled appropriately in the

statistical analysis.

• Report any relevant observation where data may be suspect due to contamination or

problems/deviations in processing in the “Additional Notes / Flags” column with the

explanation. This will be handled appropriately in the statistical analysis.

10. Statistical Analysis

A statistical analysis in general conformance with ISO 5725-2:1994 and ISO/TR 22971:2005

will be conducted. Study participants will receive “Z” scores for each reported result.

11. Tabulation and Presentation of the Data

The data will be coded by laboratory number rather than laboratory identity. The code will be

provided to the respective participating laboratory along with the tabulated data. Results will

be presented at the Fall EVAP meeting.


Appendix C – Raw Data

1. General Method Information

Lab ID

Sample Prep.

Method Digestion Type

Digestion Vessel Size

(mL)

Acid Type(s)

Acid Volume

(mL)

Sample Size (g)

Final Volume

(mL)

Final Solution Sample Matrix

Standard Solution Matrix

Make and Model of ICP-

MS used

1 Digestion Microwave Closed

Vessel HF100

{HNO3, H2O2}

{5, 2} 0.3 1 2 % (v/v) Nitric

Acid 2 % (v/v) Nitric

Acid Agilent 7700x

2 Digestion Microwave Open

Vessel 55 HNO3 10 1 100

10 % (v/v) Nitric Acid


Agilent 7700


Vessel 50

{HNO3, H2O2}

{5, 2} 0.5 50 10 % (v/v) Nitric


Acid Agilent 7500 C


Vessel 55 HNO3 5 0.5 100



Perkin Elmer NexION 300S

7 Digestion {Microwave Closed Vessel, Block Open

Vessel} {70, 100}

{HNO3, H2O2}

{5, 2} 0.5 50 5 % (v/v) Nitric


Acid Agilent 7500a


Vessel 55

{HNO3, H2O2}

{5, 2} 0.2 50 5 % (v/v) Nitric


Acid Perkin Elmer Elan DRC-e

11 Digestion {Microwave Closed Vessel, Block Open

Vessel} 100 HNO3 5 0.25 50


5 % (v/v) Nitric Acid +

0.5 % (v/v) Methanol

PERKIN ELMER

NEXION 300D


Vessel 100

{HNO3, H2O2, HCL}

{2, 10, 6} 0.5 100


6 % (v/v) Hydrochloric

Acid


Agilent 8900 ICP-MS TQ

3 Dilution N/A N/A N/A N/A 0.5 50 5 % (v/v) Nitric

Acid


1 % (v/v) Methanol

Agilent 7700x ICP-MS with

ORS

6 Dilution Acidification N/A HNO3 N/A 1.1 50 10 % (v/v) Nitric


Acid Agilent 7700x


Lab ID

Sample Prep.

Method Digestion Type

Digestion Vessel Size

(mL)

Acid Type(s)

Acid Volume

(mL)

Sample Size (g)

Final Volume

(mL)

Final Solution Sample Matrix

Standard Solution Matrix

Make and Model of ICP-

MS used

8 Dilution N/A N/A N/A N/A 0.5 50

2.0 % (v/v) Nitric Acid +

10 % (v/v) Methanol + 0.5 % (v/v)

Hydrochloric Acid

2.0 % (v/v) Nitric Acid +

10 % (v/v) Methanol + 0.5 % (v/v)

Hydrochloric Acid

Agilent 7800


Acid



Agilent 7900


Acid



PERKIN ELMER

NEXION 300D


Acid 5.0 % (v/v) Nitric

Acid Agilent 8900 ICP-MS TQ


2. Method Details: Internal Standards, Analysis Mode, Reaction Gasses, LOD and LOQ

Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]

Limit of Quantitation (LOQ)

[ng/g]

1 Arsenic Digestion 75 115In 2 Reaction Cell He 7 0.05 2.5 1.25 12.5

2 Arsenic Digestion 75 Reaction Cell He 6 1 50 4.943 14.83

3 Arsenic Dilution 75 89Y 1000 Reaction Cell He 7 1 500 13 42

4 Arsenic Digestion 75 Ge 0.5 Reaction Cell He 5 0.59 9.2 35.4 118.2

5 Arsenic Digestion 75 74Ge 50 Reaction Cell He 6 1 50 5.6 8.2

6 Arsenic Dilution 75 125Te 201 Reaction Cell He 7 1.00 50 25 50

7 Arsenic Digestion 75 72Ge 50 Normal N/A 9 0.66 50 9.7 32.2

8 Arsenic Dilution 75 103Rh Reaction Cell He 6 1 50 1.67 5

9 Arsenic Digestion 75 159Tb 10 Normal N/A 6 1 50 12 40

10 Arsenic Dilution 75 130Te 15 Reaction Cell He 0 40 4.22 14.1

11 Arsenic Digestion 75 71Ga 50 Reaction Cell He 7 0.4 10 80

12 Arsenic Dilution 75 71Ga 50 Reaction Cell He 7 0.4 10 80

13 Arsenic Digestion 75 126Te 100 Reaction Cell He 6 0.15 10 14.3 47.8

14 Arsenic Dilution 75 126Te 100 Reaction Cell He 6 0.15 10 1.37 4.56

1 Cadmium Digestion 114 115In 2 Normal N/A 7 0.03 1.5 0.76 7.5

2 Cadmium Digestion 111 Reaction Cell He 6 1 50 5.793 17.379

3 Cadmium Dilution 111 115In 1000 Reaction Cell He 7 1 500 9.6 32

4 Cadmium Digestion 111 In 0.1 Normal N/A 5 0.25 20 15 50

5 Cadmium Digestion 114 115In 10 Normal N/A 6 1 50 1.1 4.8

6 Cadmium Dilution 111 103Rh 1.25 Reaction Cell He 10 0.100 50 2.5 25

7 Cadmium Digestion 111 115In 50 Normal N/A 9 0.66 50 16.2 54.0


Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

8 Cadmium Dilution 111 115In Reaction Cell N/A 6 1 50 0.67 2

9 Cadmium Digestion 114 159Tb 10 Normal N/A 6 1 50 13 43

10 Cadmium Dilution 111 89Y 10 Reaction Cell He 0 40 8.44 28.2

11 Cadmium Digestion 111 115In 10 Reaction Cell He 7 0.4 10 80

12 Cadmium Dilution 111 115In 10 Reaction Cell He 7 0.4 10 80

13 Cadmium Digestion 111 103Rh 100 Reaction Cell He 6 0.25 50 3.26 10.9

14 Cadmium Dilution 111 103Rh 100 Reaction Cell He 6 0.25 50 1.38 4.59

1 Chromium Digestion 52 115In 2 Reaction Cell He 7 0.03 1.5 1.68 7.5

2 Chromium Digestion 52 Reaction Cell He 6 1 50 17.973 53.92

3 Chromium Dilution 52 45Sc 1000 Reaction Cell He 7 1 500 7.8 26

4 Chromium Digestion 52 Ge 0.5 Normal N/A 5 0.44 18 26.5 88.3

5 Chromium Digestion 52 71Ga 100 Reaction Cell NH3 6 1 50 1.6 160

6 Chromium Dilution 52 72Ge 25.0 Reaction Cell He 10 0.100 50.0 2.5 25

7 Chromium Digestion 53 72Ge 50.0 Normal N/A 9.0 0.66 50.0 7.5 25.2

8 Chromium Dilution 52 45Sc Reaction Cell He 6 1 50 5 15

9 Chromium Digestion 52 159Tb 10 Reaction Cell O2 6 1 50 13 43

10 Chromium Dilution 52 45Sc 10 Reaction Cell He 0 40 6.38 21.2

11 Chromium Digestion 52 71Ga 50 Reaction Cell He 7 0.4 10 80

12 Chromium Dilution 52 71Ga 50 Reaction Cell He 7 0.4 10 80

13 Chromium Digestion 52 45Sc 100 Reaction Cell He 6 0.15 12.5 26.3 87.6

14 Chromium Dilution 52 45Sc 100 Reaction Cell He 6 0.15 12.5 6.41 21.4

1 Copper Digestion 65 115In 2 Reaction Cell He 7 0.3 15 6.08 75


Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

2 Copper Digestion 63 Reaction Cell He 6 1 50 8.585 25.756

3 Copper Dilution 65 45Sc 1000 Reaction Cell He 7 1 500 9 30

4 Copper analysis not performed by participating lab

5 Copper Digestion 63 71Ga 100 Reaction Cell He 6 1 50 108 541

6 Copper Dilution 63 72Ge 25 Reaction Cell He 7 1.00 50 5 25

7 Copper Digestion 63 72Ge 50 Normal N/A 9 0.66 50 12.2 40.7

8 Copper Dilution 63 45Sc Reaction Cell He 6 1 50 6.67 20

9 Copper Digestion 64 159Tb 10 Normal N/A 6 1 50 15 50

10 Copper Dilution 63 45Sc 10 Reaction Cell He 0 40 3.52 11.7

11 Copper Digestion 63 71Ga 50 Reaction Cell He 6 4 60 800

12 Copper Dilution 63 71Ga 50 Reaction Cell He 6 4 60 800

13 Copper Digestion 63 71Ga 100 Reaction Cell He 6 0.6 50 128 427

14 Copper Dilution 63 71Ga 100 Reaction Cell He 6 0.6 50 26.8 89.3

1 Iron Digestion 56 115In 2 Reaction Cell He 7 1 50 16.61 250

2 Iron Digestion 56 Reaction Cell He 6 1 50 37.631 112.894

3 Iron Dilution 56 45Sc 1000 Reaction Cell He 7 1 500 7.9 26

4 Iron analysis not performed by participating lab

5 Iron Digestion 56 71Ga 100 Reaction Cell NH3 6 1 50 141 705

6 Iron Dilution 56 72Ge 25 Reaction Cell He 6 2.50 50 50 125

7 Iron Digestion 57 72Ge 50 Normal N/A 9 66 500 13.5 45.0

8 Iron Dilution 56 45Sc Reaction Cell H2 6 1 50 50 150

9 Iron analysis not performed by participating lab


Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

10 Iron Dilution 56 45Sc 10 Reaction Cell H2 0 40 67.8 226

11 Iron Digestion 56 71Ga 50 Reaction Cell He 5 0.4 10 80

12 Iron Dilution 56 71Ga 50 Reaction Cell He 6 0.4 10 80

13 Iron Digestion 56 45Sc 100 Reaction Cell He 6 1.25 100 538 1793

14 Iron Dilution 56 45Sc 100 Reaction Cell He 6 1.25 100 79.1 264

1 Lead Digestion 208 115In 2 Normal N/A 7 0.3 15 5.09 75

2 Lead Digestion 208 Reaction Cell He 6 1 50 15.061 45.183

3 Lead Dilution 208 175Lu 1000 Reaction Cell He 7 1 500 7.2 24

4 Lead Digestion 206 Bi 0.5 Normal N/A 5 1 10.3 59.9 199.7

5 Lead Digestion 208 209Bi 50 Normal N/A 6 1 50 1.6 36

6 Lead Dilution 208 209Bi 1.25 Reaction Cell He 10 0.100 50 2.5 25

7 Lead Digestion 208 209Bi 50 Normal N/A 9 0.66 50 12.0 40.2

8 Lead Dilution 206, 207, 208

175Lu Reaction Cell N/A 6 1 50 1.67 5

9 Lead Digestion 207 159Tb 10 Normal N/A 6 1 50 15 50

10 Lead Dilution 208 204Tl 10 Reaction Cell He 0 40 4.84 16.1

11 Lead Digestion 206 209Bi 50 Reaction Cell He 6 0.4 10 80

12 Lead Dilution 207 209Bi 50 Reaction Cell He 6 0.4 10 80

13 Lead Digestion 208 205Tl 100 Reaction Cell He 6 0.25 50 57.6 192

14 Lead Dilution 208 205Tl 100 Reaction Cell He 6 0.25 50 6.36 21.2

1 Nickel Digestion 60 115In 2 Reaction Cell He 7 0.03 1.5 1.16 7.5


Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

2 Nickel Digestion 60 Reaction Cell He 6 1 50 24.332 72.995

3 Nickel Dilution 60 45Sc 1000 Reaction Cell He 7 1 500 10 34

4 Nickel Digestion 60 Ge 0.5 Reaction Cell He 5 0.31 20.17 18.8 62.8

5 Nickel Digestion 60 71Ga 100 Reaction Cell He 6 1 50 6 64

6 Nickel Dilution 60 72Ge 25 Reaction Cell He 10 0.100 50 2.5 25

7 Nickel Digestion 60 72Ge 50 Normal N/A 9 0.66 50 9.7 32.5

8 Nickel Dilution 60 45Sc Reaction Cell He 6 1 50 6.67 20

9 Nickel Digestion 58 159Tb 10 Normal N/A 6 1 50 15 50

10 Nickel Dilution 60 45Sc 10 Reaction Cell He 0 40 4.12 13.7

11 Nickel Digestion 60 71Ga 50 Reaction Cell He 7 0.4 10 80

12 Nickel Dilution 60 71Ga 50 Reaction Cell He 6 0.4 10 80

13 Nickel Digestion 60 71Ga 100 Reaction Cell He 6 0.25 50 27.1 90.4

14 Nickel Dilution 60 71Ga 100 Reaction Cell He 6 0.25 50 1.73 5.78

1 Silver analysis not performed by participating lab

2 Silver Digestion 108 Reaction Cell He 6 1 50 10.307 30.922

3 Silver Dilution 107 115In 1000 Reaction Cell He 7 1 500 10 34


5 Silver Digestion 107 115In 10 Normal N/A 6 1 50 10.6 53

6 Silver Dilution 107 103Rh 1.25 Reaction Cell He 10 0.100 50 2.5 25

7 Silver Digestion 107 115In 50 Normal N/A 9 0.66 50 18.7 62.2

8 Silver Dilution 107 103Rh Reaction Cell N/A 6 1 50 1.67 5



Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

10 Silver Dilution 107 89Y 10 Reaction Cell H2 0 40 17.2 57.2

11 Silver Digestion 107 115In 10 Reaction Cell He 7 0.4 10 80

12 Silver Dilution 107 115In 10 Reaction Cell He 7 0.4 10 80

13 Silver Digestion 107 103Rh 100 Reaction Cell He 6 0.075 10 0.8 2.67

14 Silver Dilution 107 103Rh 100 Reaction Cell He 6 0.075 10 0.5 1.64

1 Tin Digestion 118 115In 2 Normal N/A 7 0.03 1.5 0.77 7.5

2 Tin Digestion 118 Reaction Cell He 6 1 50 38.815 116.446

3 Tin Dilution 118 115In 1000 Reaction Cell He 7 1 500 7.6 25

4 Tin analysis not performed by participating lab

5 Tin Digestion 118 115In 10 Normal N/A 6 1 50 1.3 6.4

6 Tin Dilution 118 103Rh 1.25 Reaction Cell He 7 1.00 50 25 125


8 Tin Dilution 118 103Rh Reaction Cell N/A 6 1 50 33.3 100


10 Tin Dilution 118 89Y 10 Reaction Cell H2 0 40 6.76 22.6

11 Tin Digestion 118 115In 10 Reaction Cell He 7 0.4 10 80

12 Tin Dilution 118 115In 10 Reaction Cell He 7 0.4 10 80

13 Tin Digestion 118 103Rh 100 Reaction Cell He 6 0.25 30 114 378

14 Tin Dilution 118 103Rh 100 Reaction Cell He 6 1 30 35.7 119

1 Zinc Digestion 66 115In 2 Reaction Cell He 7 1 50 18.21 250

2 Zinc analysis not performed by participating lab

3 Zinc Dilution 66 89Y 1000 Reaction Cell He 7 1 500 12 41


Lab ID

Metals Analyte

Sample Prep.

Method

Mass Internal

Standard (IS)

IS Conc. [ng/mL]

Analysis Mode

Reaction Gas Used

Standard Levels

Low Std. [ng/mL]

High Std. [ng/mL]

Limit of Detection

(LOD) [ng/g]


[ng/g]

4 Zinc analysis not performed by participating lab

5 Zinc Digestion 66 71Ga 100 Normal N/A 6 5 300 156 779

6 Zinc Dilution 66 72Ge 25 Reaction Cell He 7 1.00 50 5 50

7 Zinc Digestion 75 72Ge 50 Normal N/A 9 0.66 50 14.7 49.2

8 Zinc Dilution 66 103Rh Reaction Cell He 6 1 50 33.3 100

9 Zinc Digestion 64 159Tb 10 Normal N/A 6 1 50 15 50

10 Zinc Dilution 66 45Sc 10 Reaction Cell He 0 40 14.7 49.1

11 Zinc Digestion 66 71Ga 50 Reaction Cell He 6 4 60 800

12 Zinc Dilution 66 71Ga 50 Reaction Cell He 7 4 60 800

13 Zinc Digestion 66 71Ga 100 Reaction Cell He 6 1.25 100 259 862

14 Zinc Dilution 66 71Ga 100 Reaction Cell He 6 1.25 100 27.5 91.6


3. Raw Data Set and Basic Statistics (Mean, SD)

Lab Metals Sample LOD LOQ Sample Spiked/ Unit Summary Statistics Raw Result Laboratory Statistician

ID Analyte Prep. [ng/g] [ng/g] Number Unspiked N Mean SD Rep. 1 Rep. 2 Rep. 3 Rep. 4 Comments Comments

1 Arsenic Digestion 1.25 12.5 CS_Metal01 spiked ng/g 4 487.8 16.5 502.2 497.7 486.0 465.3





9 Arsenic Digestion 12 40 CS_Metal01 spiked ng/g 4 591.8 14.6 582.1 578.3 596.7 610.1

11 Arsenic Digestion 80 CS_Metal01 spiked ng/g 4 201.4 5.2 206.3 200.9 194.3 204.1 Mean outlier


3 Arsenic Dilution 13 42 CS_Metal01 spiked ng/g 4 440.0 16.3 462.0 442.0 425.0 431.0


8 Arsenic Dilution 1.67 5 CS_Metal01 spiked ng/g 4 535.6 31.5 554.5 513.6 570.0 504.6

10 Arsenic Dilution 4.22 14.1 CS_Metal01 spiked ng/g 4 469.2 6.6 473.1 467.9 475.2 460.4

12 Arsenic Dilution 80 CS_Metal01 spiked ng/g 4 373.5 2.6 373.5 370.6 373.2 376.9



















1 Cadmium Digestion 0.76 7.5 CS_Metal01 spiked ng/g 4 487.3 15.4 502.6 497.2 480.2 469.1


4 Cadmium Digestion 15 50 CS_Metal01 spiked ng/g 4 516.8 7.3 523.0 512.0 509.0 523.0




11 Cadmium Digestion 80 CS_Metal01 spiked ng/g 4 423.7 6.2 422.5 418.7 420.7 432.7


3 Cadmium Dilution 9.6 32 CS_Metal01 spiked ng/g 4 523.8 12.8 520.0 538.0 529.0 508.0



10 Cadmium Dilution 8.44 28.2 CS_Metal01 spiked ng/g 4 481.1 3.8 484.5 483.8 479.9 476.2

12 Cadmium Dilution 80 CS_Metal01 spiked ng/g 4 487.7 5.8 491.4 485.7 480.4 493.1



















1 Chromium Digestion 1.68 7.5 CS_Metal01 spiked ng/g 4 498.7 26.6 524.8 515.9 487.6 466.7



5 Chromium Digestion 1.6 160 CS_Metal01 spiked ng/g 4 552.2 7.3 547.9 545.4 553.5 561.8


9 Chromium Digestion 13 43 CS_Metal01 spiked ng/g 4 598.6 10.5 598.1 586.9 612.4 596.9

11 Chromium Digestion 80 CS_Metal01 spiked ng/g 4 396.6 2.7 393.5 397.9 395.3 399.7


3 Chromium Dilution 7.8 26 CS_Metal01 spiked ng/g 4 536.3 5.3 538.0 543.0 532.0 532.0


8 Chromium Dilution 5 15 CS_Metal01 spiked ng/g 4 506.6 28.7 521.4 491.3 538.6 475.0

10 Chromium Dilution 6.38 21.2 CS_Metal01 spiked ng/g 4 464.6 31.4 488.7 493.3 447.1 429.4

12 Chromium Dilution 80 CS_Metal01 spiked ng/g 4 417.3 5.7 411.0 414.7 419.1 424.2



















1 Copper Digestion 6.08 75 CS_Metal01 spiked ng/g 4 492.3 16.7 507.1 500.0 493.4 468.7

2 Copper Digestion 8.585 25.756 CS_Metal01 spiked ng/g 4 458.8 12.4 447.5 475.6 452.0 460.1

5 Copper Digestion 108 541 CS_Metal01 spiked ng/g 4 685.0 106.6 838.2 676.6 617.6 607.5



11 Copper Digestion 800 CS_Metal01 spiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800 exclude


3 Copper Dilution 9 30 CS_Metal01 spiked ng/g 4 531.8 5.7 531.0 540.0 529.0 527.0


8 Copper Dilution 6.67 20 CS_Metal01 spiked ng/g 4 502.7 28.5 521.7 484.0 531.9 473.2

10 Copper Dilution 3.52 11.7 CS_Metal01 spiked ng/g 4 486.4 10.4 495.9 491.7 486.0 472.1

12 Copper Dilution 800 CS_Metal01 spiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800 exclude







11 Copper Digestion 800 CS_Metal02 spiked ng/g 4 1038.9 4.8 1038.1 1042.6 1032.5 1042.7 Mean outlier






















12 Copper Dilution 800 CS_Metal03 spiked ng/g 4 NQ NQ < 800 < 800 < 800 1135.9 exclude


















1 Iron Digestion 16.61 250 CS_Metal01 spiked ng/g 4 716.3 64.3 659.3 799.4 734.1 672.4

2 Iron Digestion 37.631 112.894 CS_Metal01 spiked ng/g 4 559.3 10.9 554.8 574.9 557.5 550.0

5 Iron Digestion 141 705 CS_Metal01 spiked ng/g 4 937.9 127.0 959.9 825.4 858.3 1108.0


11 Iron Digestion 80 CS_Metal01 spiked ng/g 4 617.5 6.1 609.3 622.9 616.6 621.1

13 Iron Digestion 538 1793 CS_Metal01 spiked ng/g 4 890.8 195.6 825.1 794.1 1181.7 762.3 Include:

Comparable

3 Iron Dilution 7.9 26 CS_Metal01 spiked ng/g 4 639.8 22.0 639.0 671.0 627.0 622.0

6 Iron Dilution 50 125 CS_Metal01 spiked ng/g 4 622.4 60.5 713.1 591.8 593.5 591.0



12 Iron Dilution 80 CS_Metal01 spiked ng/g 4 508.8 29.6 518.9 480.3 490.3 545.7





Comparable




Comparable













Comparable




Comparable










Comparable




Comparable










1 Lead Digestion 5.09 75 CS_Metal01 spiked ng/g 4 522.8 21.0 549.1 528.0 514.5 499.5

2 Lead Digestion 15.061 45.183 CS_Metal01 spiked ng/g 4 433.7 15.3 449.0 444.5 422.7 418.6




9 Lead Digestion 15 50 CS_Metal01 spiked ng/g 4 493.6 14.9 492.3 506.1 473.0 502.9

11 Lead Digestion 80 CS_Metal01 spiked ng/g 4 632.1 5.9 640.1 626.0 632.6 629.9


3 Lead Dilution 7.2 24 CS_Metal01 spiked ng/g 4 518.8 9.0 517.0 532.0 513.0 513.0



10 Lead Dilution 4.84 16.1 CS_Metal01 spiked ng/g 4 479.0 2.1 481.3 480.1 477.9 476.7

12 Lead Dilution 80 CS_Metal01 spiked ng/g 4 574.7 8.2 575.3 581.2 562.9 579.4



















1 Nickel Digestion 1.16 7.5 CS_Metal01 spiked ng/g 4 501.9 29.5 540.2 509.9 480.8 476.9



5 Nickel Digestion 6 64 CS_Metal01 spiked ng/g 4 530.9 10.7 520.4 540.7 523.0 539.6



11 Nickel Digestion 80 CS_Metal01 spiked ng/g 4 508.5 9.2 504.1 522.1 506.0 501.9


3 Nickel Dilution 10 34 CS_Metal01 spiked ng/g 4 539.3 8.5 544.0 548.0 536.0 529.0

6 Nickel Dilution 2.5 25 CS_Metal01 spiked ng/g 4 505.4 2.2 507.4 504.5 507.1 502.8


10 Nickel Dilution 4.12 13.7 CS_Metal01 spiked ng/g 4 476.7 16.1 496.7 460.3 481.9 468.0

12 Nickel Dilution 80 CS_Metal01 spiked ng/g 4 446.2 6.5 446.8 448.8 437.1 452.2



















2 Silver Digestion 10.307 30.922 CS_Metal01 spiked ng/g 4 548.4 46.3 617.0 518.7 522.9 534.8

5 Silver Digestion 10.6 53 CS_Metal01 spiked ng/g 4 50.4 2.4 53.3 49.1 47.9 51.3 Mean outlier


11 Silver Digestion 80 CS_Metal01 spiked ng/g 4 428.9 4.4 430.3 424.6 426.3 434.5


3 Silver Dilution 10 34 CS_Metal01 spiked ng/g 4 524.3 7.8 525.0 533.0 525.0 514.0

6 Silver Dilution 2.5 25 CS_Metal01 spiked ng/g 4 490.4 4.3 493.5 494.6 488.0 485.7


10 Silver Dilution 17.2 57.2 CS_Metal01 spiked ng/g 4 479.2 3.6 474.8 479.4 479.0 483.6

12 Silver Dilution 80 CS_Metal01 spiked ng/g 4 466.9 9.2 467.7 455.8 478.3 465.7
















1 Tin Digestion 0.77 7.5 CS_Metal01 spiked ng/g 4 491.6 21.1 511.9 499.1 493.2 462.1



11 Tin Digestion 80 CS_Metal01 spiked ng/g 4 497.0 2.8 497.7 493.4 496.8 500.2

13 Tin Digestion 114 378 CS_Metal01 spiked ng/g 4 478.3 7.4 468.0 481.1 485.2 479.0

3 Tin Dilution 7.6 25 CS_Metal01 spiked ng/g 4 513.3 10.0 516.0 524.0 513.0 500.0

6 Tin Dilution 25 125 CS_Metal01 spiked ng/g 4 477.8 5.3 485.3 477.6 475.5 473.0


10 Tin Dilution 6.76 22.6 CS_Metal01 spiked ng/g 4 491.9 7.3 482.4 490.0 497.0 498.2

12 Tin Dilution 80 CS_Metal01 spiked ng/g 4 499.9 4.2 503.5 502.4 494.1 499.4
















1 Zinc Digestion 18.21 250 CS_Metal01 spiked ng/g 4 464.3 21.5 485.0 472.5 465.2 434.4

5 Zinc Digestion 156 779 CS_Metal01 spiked ng/g 4 795.3 23.8 819.4 764.7 789.5 807.7 Include:

Comparable

7 Zinc Digestion 14.7 49.2 CS_Metal01 spiked ng/g 4 305.1 9.1 316.5 305.2 294.3 304.3

9 Zinc Digestion 15 50 CS_Metal01 spiked ng/g 4 499.6 19.0 476.8 523.3 498.0 500.4

11 Zinc Digestion 800 CS_Metal01 spiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800 exclude


3 Zinc Dilution 12 41 CS_Metal01 spiked ng/g 4 512.5 3.3 508.0 513.0 516.0 513.0


8 Zinc Dilution 33.3 100 CS_Metal01 spiked ng/g 4 537.4 38.4 554.5 526.4 579.2 489.7

10 Zinc Dilution 14.7 49.1 CS_Metal01 spiked ng/g 4 497.2 10.0 487.8 498.5 510.6 491.9

12 Zinc Dilution 800 CS_Metal01 spiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800 exclude




Comparable



11 Zinc Digestion 800 CS_Metal02 spiked ng/g 4 1087.8 15.3 1090.1 1108.6 1076.7 1075.9


Comparable












Comparable



11 Zinc Digestion 800 CS_Metal03 spiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800 exclude


Comparable









7 Zinc Digestion 14.7 49.2 CS_Metal04 spiked ng/g 4 NQ NQ ND ND ND ND exclude


11 Zinc Digestion 800 CS_Metal04 spiked ng/g 4 981.7 12.1 988.9 963.7 988.9 985.4

13 Zinc Digestion 259 862 CS_Metal04 spiked ng/g 4 832.5 56.1 888.7 828.0 757.0 856.3 Include

Comparable










1 Arsenic Digestion 1.25 12.5 CS_Metal01 unspiked ng/g 4 NQ NQ 4.7 3.5 4.4 4.3

2 Arsenic Digestion 4.943 14.83 CS_Metal01 unspiked ng/g 4 NQ NQ < 4.943 < 4.943 < 4.943 < 4.943



7 Arsenic Digestion 9.7 32.2 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Arsenic Digestion 12 40 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Arsenic Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80


3 Arsenic Dilution 13 42 CS_Metal01 unspiked ng/g 4 NQ NQ 37.6 22.7 19.7 13.6

6 Arsenic Dilution 25 50 CS_Metal01 unspiked ng/g 4 NQ NQ 25.8 23.8 19.7 17.9 Disregard replicate 1

8 Arsenic Dilution 1.67 5 CS_Metal01 unspiked ng/g 4 6.6 0.6 7.1 7.2 6.2 6.0

10 Arsenic Dilution 4.22 14.1 CS_Metal01 unspiked ng/g 4 NQ NQ LOQ(6.52) LOQ(11.3) LOQ(8.75) LOD(3.94)

12 Arsenic Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Arsenic Dilution 1.37 4.56 CS_Metal01 unspiked ng/g 4 NQ NQ 3.62 3.89 3.52 3.75








13 Arsenic Digestion 14.3 47.8 CS_Metal02 unspiked ng/g 4 49.7 1.4 50.5 48.4 51.2 48.7



8 Arsenic Dilution 1.67 5 CS_Metal02 unspiked ng/g 4 NQ NQ 4.3 3.2 4.6 3.4

10 Arsenic Dilution 4.22 14.1 CS_Metal02 unspiked ng/g 4 NQ NQ LOQ(4.58) LOQ(5.83) LOD(4.05) LOD(3.63)

















10 Arsenic Dilution 4.22 14.1 CS_Metal03 unspiked ng/g 4 NQ NQ LOD(3.69) LOQ(4.27) LOD(3.05) LOD(3.84)














10 Arsenic Dilution 4.22 14.1 CS_Metal04 unspiked ng/g 4 NQ NQ LOD(2.84) LOD(2.79) LOD(2.30) LOD(3.00)






1 Cadmium Digestion 0.76 7.5 CS_Metal01 unspiked ng/g 4 NQ NQ 0.9 1.0 1.1 1.1

2 Cadmium Digestion 5.793 17.379 CS_Metal01 unspiked ng/g 4 NQ NQ < 5.793 < 5.793 < 5.793 < 5.793

4 Cadmium Digestion 15 50 CS_Metal01 unspiked ng/g 4 NQ NQ 0 4.1 3.0 0

5 Cadmium Digestion 1.1 4.8 CS_Metal01 unspiked ng/g 4 NQ NQ <LOD <LOD <LOD <LOD

7 Cadmium Digestion 16.2 54.0 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Cadmium Digestion 13 43 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Cadmium Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80


3 Cadmium Dilution 9.6 32 CS_Metal01 unspiked ng/g 4 NQ NQ 0.178 0.342 0.204 0.223

6 Cadmium Dilution 2.5 25 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0.024 0 0


10 Cadmium Dilution 8.44 28.2 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(0.638) LOD(0.727) LOD(0.693) LOD(0.251)

12 Cadmium Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Cadmium Dilution 1.38 4.59 CS_Metal01 unspiked ng/g 4 NQ NQ 0.152 0.166 0.126 0.303










6 Cadmium Dilution 2.5 25 CS_Metal02 unspiked ng/g 4 NQ NQ 0 0 0 0
















3 Cadmium Dilution 9.6 32 CS_Metal03 unspiked ng/g 4 NQ NQ 0.0863 0.0438 <0.000 <0.000

6 Cadmium Dilution 2.5 25 CS_Metal03 unspiked ng/g 4 NQ NQ 0 0 0 0














6 Cadmium Dilution 2.5 25 CS_Metal04 unspiked ng/g 4 NQ NQ 0 0.034 0 0.010








1 Chromium Digestion 1.68 7.5 CS_Metal01 unspiked ng/g 4 NQ NQ 5.5 3.9 7.2 4.1

2 Chromium Digestion 17.973 53.92 CS_Metal01 unspiked ng/g 4 NQ NQ < 17.973 < 17.973 < 17.973 < 17.973


5 Chromium Digestion 1.6 160 CS_Metal01 unspiked ng/g 4 NQ NQ 11.4 36.0 14.6 60.9

7 Chromium Digestion 7.5 25.2 CS_Metal01 unspiked ng/g 4 240.3 26.6 229.8 279.5 231.3 220.4 questionable

9 Chromium Digestion 13 43 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Chromium Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80


3 Chromium Dilution 7.8 26 CS_Metal01 unspiked ng/g 4 NQ NQ 0.233 0.33 0.133 0.364


8 Chromium Dilution 5 15 CS_Metal01 unspiked ng/g 4 NQ NQ 0.0 1.0 1.7 0.0

10 Chromium Dilution 6.38 21.2 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(2.84) LOQ(6.81) LOQ(13.4) LOD(0.00)

12 Chromium Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Chromium Dilution 6.41 21.4 CS_Metal01 unspiked ng/g 4 NQ NQ 19.4 18.1 21.3 17.8

1 Chromium Digestion 1.68 7.5 CS_Metal02 unspiked ng/g 4 NQ NQ 9.6 4.5 3.9 NC replicate 4:

not confirmed




7 Chromium Digestion 7.5 25.2 CS_Metal02 unspiked ng/g 4 NQ NQ ND ND ND ND




3 Chromium Dilution 7.8 26 CS_Metal02 unspiked ng/g 4 NQ NQ 0.41 0.0757 <0.000 0.0388



10 Chromium Dilution 6.38 21.2 CS_Metal02 unspiked ng/g 4 NQ NQ LOD(6.91) LOD(3.67) LOD(5.80) LOD(0.00)






1 Chromium Digestion 1.68 7.5 CS_Metal03 unspiked ng/g 4 NQ NQ 4.0 5.3 4.3 NC replicate 4:

not confirmed


4 Chromium Digestion 26.5 88.3 CS_Metal03 unspiked ng/g 4 130.6 47.8 142.3 98.0 193.1 88.9
















7 Chromium Digestion 7.5 25.2 CS_Metal04 unspiked ng/g 4 NQ NQ ND ND ND ND




3 Chromium Dilution 7.8 26 CS_Metal04 unspiked ng/g 4 NQ NQ 0.71 0.0223 <0.000 0.106









1 Copper Digestion 6.08 75 CS_Metal01 unspiked ng/g 4 NQ NQ 0.4 4.5 3.6 1.2

2 Copper Digestion 8.585 25.756 CS_Metal01 unspiked ng/g 4 NQ NQ 12.3 < 8.585 < 8.585 < 8.585

5 Copper Digestion 108 541 CS_Metal01 unspiked ng/g 4 NQ NQ 159.0 82.5 76.2 156.1

7 Copper Digestion 12.2 40.7 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Copper Digestion 15 50 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Copper Digestion 800 CS_Metal01 unspiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800


3 Copper Dilution 9 30 CS_Metal01 unspiked ng/g 4 NQ NQ <0.000 <0.000 <0.000 <0.000

6 Copper Dilution 5 25 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0 0.2 0

8 Copper Dilution 6.67 20 CS_Metal01 unspiked ng/g 4 NQ NQ 0.0 0.0 0.0 0.0

10 Copper Dilution 3.52 11.7 CS_Metal01 unspiked ng/g 4 NQ NQ LOQ(7.07) LOQ(4.30) LOQ(8.68) LOD(0.00)

12 Copper Dilution 800 CS_Metal01 unspiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800

14 Copper Dilution 26.8 89.3 CS_Metal01 unspiked ng/g 4 NQ NQ 0.976 0.473 1.66 0.198


2 Copper Digestion 8.585 25.756 CS_Metal02 unspiked ng/g 4 NQ NQ < 8.585 < 8.585 < 8.585 < 8.585




11 Copper Digestion 800 CS_Metal02 unspiked ng/g 4 1146.6 10.6 1139.1 1149.7 1160.2 1137.2 questionable

13 Copper Digestion 128 427 CS_Metal02 unspiked ng/g 4 NQ NQ 143 4.49 6.16 13.1


6 Copper Dilution 5 25 CS_Metal02 unspiked ng/g 4 NQ NQ 0 0.6 0 0


10 Copper Dilution 3.52 11.7 CS_Metal02 unspiked ng/g 4 NQ NQ LOQ(6.07) LOD(1.83) LOQ(5.80) LOD(0.00)







2 Copper Digestion 8.585 25.756 CS_Metal03 unspiked ng/g 4 NQ NQ < 8.585 < 8.585 < 8.585 13.4







6 Copper Dilution 5 25 CS_Metal03 unspiked ng/g 4 NQ NQ 0 0 0 0


10 Copper Dilution 3.52 11.7 CS_Metal03 unspiked ng/g 4 NQ NQ LOD(2.31) LOD(0.01) LOD(2.32) LOD(0.00)




2 Copper Digestion 8.585 25.756 CS_Metal04 unspiked ng/g 4 NQ NQ < 8.585 < 8.585 < 8.585 12.6







6 Copper Dilution 5 25 CS_Metal04 unspiked ng/g 4 NQ NQ 0 0 0 0


10 Copper Dilution 3.52 11.7 CS_Metal04 unspiked ng/g 4 NQ NQ LOD(3.27) LOD(0.00) LOD(3.43) LOD(0.00)






1 Iron Digestion 16.61 250 CS_Metal01 unspiked ng/g 4 NQ NQ 115.1 117.3 187.6 258.6

2 Iron Digestion 37.631 112.894 CS_Metal01 unspiked ng/g 4 NQ NQ 120.0 92.4 105.2 99.9

5 Iron Digestion 141 705 CS_Metal01 unspiked ng/g 4 NQ NQ 483.2 396.6 274.4 542.4

7 Iron Digestion 13.5 45.0 CS_Metal01 unspiked ng/g 4 220.4 8.6 209.4 228.3 226.0 217.8

11 Iron Digestion 80 CS_Metal01 unspiked ng/g 4 356.4 20.3 331.1 353.1 380.3 361.2

13 Iron Digestion 538 1793 CS_Metal01 unspiked ng/g 4 NQ NQ 415 332 353 806

3 Iron Dilution 7.9 26 CS_Metal01 unspiked ng/g 4 76.8 1.0 75.7 76.5 77 78.1

6 Iron Dilution 50 125 CS_Metal01 unspiked ng/g 4 NQ NQ 92.1 98.5 93.0 94.3


10 Iron Dilution 67.8 226 CS_Metal01 unspiked ng/g 4 NQ NQ LOQ(137.3) LOQ(115.4) LOQ(115.4) LOQ(114.3)

12 Iron Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 92.0 < 80

14 Iron Dilution 79.1 264 CS_Metal01 unspiked ng/g 4 NQ NQ 99.9 88.6 116 85.3

1 Iron Digestion 16.61 250 CS_Metal02 unspiked ng/g 4 347.6 217.9 567.8 174.7 146.5 501.4




11 Iron Digestion 80 CS_Metal02 unspiked ng/g 4 9744.0 95.5 9877.6 9745.0 9661.4 9692.1 very high,

questionable


3 Iron Dilution 7.9 26 CS_Metal02 unspiked ng/g 4 112.3 6.7 118 118 107 106




12 Iron Dilution 80 CS_Metal02 unspiked ng/g 4 154.6 67.4 134.3 123.3 254.3 106.6

14 Iron Dilution 79.1 264 CS_Metal02 unspiked ng/g 4 NQ NQ 163 121 122 116




1 Iron Digestion 16.61 250 CS_Metal03 unspiked ng/g 4 678.4 801.6 154.5 426.7 263.5 1869.0

2 Iron Digestion 37.631 112.894 CS_Metal03 unspiked ng/g 4 NQ NQ 140.6 108.2 111.3 108.3



11 Iron Digestion 80 CS_Metal03 unspiked ng/g 4 605.5 22.2 633.3 583.1 593.0 612.4






12 Iron Dilution 80 CS_Metal03 unspiked ng/g 4 277.9 162.2 359.1 176.1 112.5 463.9


1 Iron Digestion 16.61 250 CS_Metal04 unspiked ng/g 4 NQ NQ 161.6 196.4 299.0 330.1




11 Iron Digestion 80 CS_Metal04 unspiked ng/g 4 58331.5 515.6 58066.0 58026.0 58131.9 59102.1 very high,

questionable






12 Iron Dilution 80 CS_Metal04 unspiked ng/g 4 NQ NQ 124.8 < 80 89.0 < 80





1 Lead Digestion 5.09 75 CS_Metal01 unspiked ng/g 4 NQ NQ 21.4 16.6 17.6 15.9

2 Lead Digestion 15.061 45.183 CS_Metal01 unspiked ng/g 4 NQ NQ 31.2 < 15.061 < 15.061 < 15.061

4 Lead Digestion 59.9 199.7 CS_Metal01 unspiked ng/g 4 NQ NQ 7.3 22.3 12.1 0

5 Lead Digestion 1.6 36 CS_Metal01 unspiked ng/g 4 NQ NQ 11.1 8.8 8.4 51.2 replicate 4:

contamination

7 Lead Digestion 12.0 40.2 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Lead Digestion 15 50 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Lead Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80


3 Lead Dilution 7.2 24 CS_Metal01 unspiked ng/g 4 NQ NQ 0.0912 0.0517 0.076 0.0538

6 Lead Dilution 2.5 25 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0 0 0


10 Lead Dilution 4.84 16.1 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(0.986) LOD(0.331) LOD(1.63) LOD(0.905)

12 Lead Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Lead Dilution 6.36 21.2 CS_Metal01 unspiked ng/g 4 NQ NQ 0.329 0.213 0.086 0.995


2 Lead Digestion 15.061 45.183 CS_Metal02 unspiked ng/g 4 NQ NQ < 15.061 < 15.061 < 15.061 < 15.061





11 Lead Digestion 80 CS_Metal02 unspiked ng/g 4 118.6 1.7 117.4 119.1 120.7 117.1 questionable


3 Lead Dilution 7.2 24 CS_Metal02 unspiked ng/g 4 NQ NQ <0.000 0.0639 0.0399 0.0108










2 Lead Digestion 15.061 45.183 CS_Metal03 unspiked ng/g 4 NQ NQ < 15.061 39.3 < 15.061 19.8







3 Lead Dilution 7.2 24 CS_Metal03 unspiked ng/g 4 NQ NQ 0.0176 0.0156 <0.000 0.0276







2 Lead Digestion 15.061 45.183 CS_Metal04 unspiked ng/g 4 NQ NQ < 15.061 < 15.061 < 15.061 40.6







3 Lead Dilution 7.2 24 CS_Metal04 unspiked ng/g 4 NQ NQ 0.0426 <0.000 0.0263 0.0291









1 Nickel Digestion 1.16 7.5 CS_Metal01 unspiked ng/g 4 NQ NQ 6.5 3.1 2.0 1.3

2 Nickel Digestion 24.332 72.995 CS_Metal01 unspiked ng/g 4 NQ NQ < 24.332 < 24.332 < 24.332 < 24.332

4 Nickel Digestion 18.8 62.8 CS_Metal01 unspiked ng/g 4 NQ NQ 59.2 42.1 10.0 0

5 Nickel Digestion 6 64 CS_Metal01 unspiked ng/g 4 NQ NQ 8.8 21.8 8.6 23.5

7 Nickel Digestion 9.7 32.5 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Nickel Digestion 15 50 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Nickel Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80


3 Nickel Dilution 10 34 CS_Metal01 unspiked ng/g 4 NQ NQ 1.04 1.15 0.779 0.792

6 Nickel Dilution 2.5 25 CS_Metal01 unspiked ng/g 4 NQ NQ 1.8 2.3 2.2 2.3


10 Nickel Dilution 4.12 13.7 CS_Metal01 unspiked ng/g 4 NQ NQ LOQ(11.1) LOQ(4.88) LOQ(10.7) LOD(0.00)

12 Nickel Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Nickel Dilution 1.73 5.78 CS_Metal01 unspiked ng/g 4 NQ NQ 1.47 1.29 1.29 0.938

1 Nickel Digestion 1.16 7.5 CS_Metal02 unspiked ng/g 4 NQ NQ 8.3 8.7 NC 3.7 replicate 3:

not confirmed



5 Nickel Digestion 6 64 CS_Metal02 unspiked ng/g 4 NQ NQ 194.1 3.3 1.5 1.3 replicate 1:

contamination








10 Nickel Dilution 4.12 13.7 CS_Metal02 unspiked ng/g 4 NQ NQ LOQ(7.48) LOD(0.00) LOQ(8.25) LOD(0.00)






1 Nickel Digestion 1.16 7.5 CS_Metal03 unspiked ng/g 4 NQ NQ 0 4.0 7.0 1.9











10 Nickel Dilution 4.12 13.7 CS_Metal03 unspiked ng/g 4 NQ NQ LOD(1.91) LOD(0.00) LOD(0.221) LOD(0.00)



1 Nickel Digestion 1.16 7.5 CS_Metal04 unspiked ng/g 4 NQ NQ 0 NC 5.9 0.7 replicate 2:

not confirmed











10 Nickel Dilution 4.12 13.7 CS_Metal04 unspiked ng/g 4 NQ NQ LOQ(6.05) LOD(0.00) LOD(2.97) LOD(0.00)






2 Silver Digestion 10.307 30.922 CS_Metal01 unspiked ng/g 4 52.2 20.9 62.8 67.5 21.4 57.0

5 Silver Digestion 10.6 53 CS_Metal01 unspiked ng/g 4 NQ NQ <LOD <LOD <LOD <LOD

7 Silver Digestion 18.7 62.2 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

11 Silver Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

13 Silver Digestion 0.8 2.67 CS_Metal01 unspiked ng/g 4 NQ NQ 0.188 0.434 0.169 0.291

3 Silver Dilution 10 34 CS_Metal01 unspiked ng/g 4 NQ NQ <0.000 <0.000 <0.000 <0.000

6 Silver Dilution 2.5 25 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0 0 0

8 Silver Dilution 1.67 5 CS_Metal01 unspiked ng/g 4 NQ NQ 0.6 0.2 0.6 0.5

10 Silver Dilution 17.2 57.2 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(1.41) LOD(1.11) LOD(1.62) LOD(1.40)

12 Silver Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

14 Silver Dilution 0.5 1.64 CS_Metal01 unspiked ng/g 4 NQ NQ 0.173 0.178 0.164 0.236

2 Silver Digestion 10.307 30.922 CS_Metal02 unspiked ng/g 4 NQ NQ < 10.307 102.0 55.9 < 10.307

5 Silver Digestion 10.6 53 CS_Metal02 unspiked ng/g 4 NQ NQ 0.8 <LOD <LOD <LOD













2 Silver Digestion 10.307 30.922 CS_Metal03 unspiked ng/g 4 NQ NQ 17.5 53.8 < 10.307 34.2

5 Silver Digestion 10.6 53 CS_Metal03 unspiked ng/g 4 NQ NQ 0.7 0.1 <LOD <LOD










2 Silver Digestion 10.307 30.922 CS_Metal04 unspiked ng/g 4 NQ NQ 40.6 40.1 < 10.307 37.0

5 Silver Digestion 10.6 53 CS_Metal04 unspiked ng/g 4 NQ NQ <LOD <LOD <LOD <LOD






8 Silver Dilution 1.67 5 CS_Metal04 unspiked ng/g 4 NQ NQ 0.1 0 0 0







1 Tin Digestion 0.77 7.5 CS_Metal01 unspiked ng/g 4 NQ NQ 0.6 0.9 3.4 0.9

2 Tin Digestion 38.815 116.446 CS_Metal01 unspiked ng/g 4 NQ NQ < 38.815 < 38.815 < 38.815 < 38.815

5 Tin Digestion 1.3 6.4 CS_Metal01 unspiked ng/g 4 NQ NQ 15.0 3.9 2.3 5.2 replicate 1:

contamination

11 Tin Digestion 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80

13 Tin Digestion 114 378 CS_Metal01 unspiked ng/g 4 NQ NQ 14.3 24.1 13.5 14.3

3 Tin Dilution 7.6 25 CS_Metal01 unspiked ng/g 4 NQ NQ 0.812 0.487 0.93 0.66

6 Tin Dilution 25 125 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0 0 0


10 Tin Dilution 6.76 22.6 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(5.21) LOD(6.28) LOQ(17.0) LOQ(17.7)

12 Tin Dilution 80 CS_Metal01 unspiked ng/g 4 NQ NQ < 80 < 80 < 80 < 80












14 Tin Dilution 35.7 119 CS_Metal02 unspiked ng/g 4 NQ NQ 0 0 0.372 0.952






5 Tin Digestion 1.3 6.4 CS_Metal03 unspiked ng/g 4 NQ NQ 2.3 3.2 7.4 5.3 replicate 3:

contamination








14 Tin Dilution 35.7 119 CS_Metal03 unspiked ng/g 4 NQ NQ 1.97 0 0.517 0








8 Tin Dilution 33.3 100 CS_Metal04 unspiked ng/g 4 NQ NQ 0 0 0 0

10 Tin Dilution 6.76 22.6 CS_Metal04 unspiked ng/g 4 NQ NQ LOD(1.73) LOD(5.96) LOQ(13.0) LOD(3.55)


14 Tin Dilution 35.7 119 CS_Metal04 unspiked ng/g 4 NQ NQ 0.214 0 0 0.012




1 Zinc Digestion 18.21 250 CS_Metal01 unspiked ng/g 4 NQ NQ 2.6 0.0 0.0 0.0

5 Zinc Digestion 156 779 CS_Metal01 unspiked ng/g 4 NQ NQ 406.3 464.0 151.5 305.6

7 Zinc Digestion 14.7 49.2 CS_Metal01 unspiked ng/g 4 NQ NQ ND ND ND ND

9 Zinc Digestion 15 50 CS_Metal01 unspiked ng/g 4 NQ NQ N N N N

11 Zinc Digestion 800 CS_Metal01 unspiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800

13 Zinc Digestion 259 862 CS_Metal01 unspiked ng/g 4 NQ NQ 383 316 260 272

3 Zinc Dilution 12 41 CS_Metal01 unspiked ng/g 4 NQ NQ 0.983 3.56 1.94 1.41

6 Zinc Dilution 5 50 CS_Metal01 unspiked ng/g 4 NQ NQ 0 0 0 0

8 Zinc Dilution 33.3 100 CS_Metal01 unspiked ng/g 4 NQ NQ 8.1 3.6 2.9 4.3

10 Zinc Dilution 14.7 49.1 CS_Metal01 unspiked ng/g 4 NQ NQ LOD(0.00) LOD(5.01) LOD(0.261) LOD(0.00)

12 Zinc Dilution 800 CS_Metal01 unspiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800

14 Zinc Dilution 27.5 91.6 CS_Metal01 unspiked ng/g 4 NQ NQ 11.8 23.3 18.1 25.5





11 Zinc Digestion 800 CS_Metal02 unspiked ng/g 4 1748.2 16.7 1742.6 1773.0 1738.1 1739.0 questionable



6 Zinc Dilution 5 50 CS_Metal02 unspiked ng/g 4 NQ NQ 0.2 0.6 1.6 0








1 Zinc Digestion 18.21 250 CS_Metal03 unspiked ng/g 4 NQ NQ 4.1 3.5 0 0




11 Zinc Digestion 800 CS_Metal03 unspiked ng/g 4 NQ NQ < 800 < 800 < 800 < 800



6 Zinc Dilution 5 50 CS_Metal03 unspiked ng/g 4 NQ NQ 0 0 0 16.2


10 Zinc Dilution 14.7 49.1 CS_Metal03 unspiked ng/g 4 NQ NQ LOD(10.0) LOD(0.00) LOQ(30.2) LOD(2.79) replicate 3:

contamination







11 Zinc Digestion 800 CS_Metal04 unspiked ng/g 4 1470.4 20.8 1493.7 1468.6 1443.6 1475.8 questionable


3 Zinc Dilution 12 41 CS_Metal04 unspiked ng/g 4 NQ NQ 6.91 5.33 2 30.4

6 Zinc Dilution 5 50 CS_Metal04 unspiked ng/g 4 NQ NQ 0 0 0 0





Result is below the limit of detection (LOD) reported by the participating lab

Result is below the limit of quantitation (LOQ) reported by the participating lab


Appendix D – Mandel’s h and k Graphs for Outlier Identification

Arsenic [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation


Arsenic [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Cadmium [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Cadmium [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Chromium [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Chromium [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Copper [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Note: Lab 11 CS_Metals02 was excluded from all spiked e-liquid test product summary statistics due to identified mean outliers.

Copper [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Iron [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Iron [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Lead [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Lead [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Nickel [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Nickel [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Silver [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Silver [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Tin [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation


Tin [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Zinc [ng/g] in spiked e-liquid test products: Mandel’s h statistic for mean outlier evaluation

Zinc [ng/g] in spiked e-liquid test products: Mandel’s k statistic for variance outlier evaluation


Appendix E – Spiked E-Liquid Test Product Summary Figures

Arsenic [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method

Cadmium [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep

method


Chromium [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep

method

Copper [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep

method


Iron [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method

Lead [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method


Nickel [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method

Silver [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method


Tin [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method

Zinc [ng/g]: general mean (�̂�) ± Sr and general mean (�̂�) ± SR for each sample prep method

technical report metals analysis method for e-liquids€¦ · evap-184-ctr-metals analysis method...

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