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Determination of Nanoparticle Size-and Number Concentration using the npQuant Evaluation Module for Qtegra ISDS

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A Task Set for a Modern ICP-MS Lab…

Total Element

QuantificationSpeciation

Analysis

Nanoparticle

CharacterizationAg

Pb

Si

As

Sample PrepCr

IC-ICP-MS

Ce

FFF-ICP-MS

Ti

Al

Quality

Control

spICP-MS

HPLC-ICP-MS

HgCd

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Nanoparticle Characterization…

Method

DevelopmentEnvironmental

Impact/Fate

Human Health

Fe

Ti

Si

Ag

Tissues

FFF

Food

Au

Waters

Ce

SerumC

Soil

Al

Matrix

Effects

Breath

HDCsp-ICP-MS

Sample

Prep

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Key Requirements

• User Guidance through Method Defintion

• Automated Determination of key input parameters

• Options to effectively judge Data Quality

• Recognition of artefacts or false positives

• Ease of use in Routine Application

• Same look and feel for lab personnel

• Training requirements

• Option to seamlessly switch to different applications

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The Nanodefine EU project

• The research leading to these results has received funding

from the European Union Seventh Framework Programme

(FP7/2007-2013) under grant agreement no. 604347

• Thermo Fisher is one partner among many others, academic

and industry

www.nanodefine.eu

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Thermo Scientific iCAP Q for spICP-MS

• Increased Detection Sensitivity

through dedicated high sensitivity

skimmer cone insert

• Fast data acquisition and real-time

display during measurement in the

single-particle mode (as low as

0.1ms)

• Dedicated evaluation software for

Qtegra ISDS

Straightforward setup, no peripherals required

Direct information about particle size and concentration

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Artefacts in spICP-MS

- Split Particle Events (B): A nanoparticle signal is observed in two adjacent

measurement slots. The extent of split particle events depends on the

nanoparticle pulse duration and the applied dwell time, and can be reduced by

using longer dwell times.

- Double or Multiple Particle Events (C): Two or more particles are observed in

one measurement slot, leading to an overestimation of the particle size. The

occurrence of such events can be estimated using Poisson statistics and can be

reduced by sample dilution.

~ 300 µs

Inte

nsit

y [

cts

] dwell

time

dwell

time

A B C

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npQuant - A new Evaluation Module

• npQuant Evaluation

Module

• Dedicated solution for

spICP-MS data

acquisition and

evaluation

• Available as add-on to

Qtegra ISDS 2.6

• Create Templates and LabBooks

• Uses Qtegra platform architecture to control peripheral devices

• LabBooks using different evaluation modules can be easily mixed

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Features

• Default Evaluation Parameters can be

determined through npQuant

• Transport Efficiency through particle measurement*

• Option to manually insert value

• Detection Sensitivity through calibration with ionic

standards

* Pace et al., Anal. Chem. 83 (2011), 9361-9369

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Features

• Multiple particle fractions can be evaluated

• Different size regimes in one sample

• Editor allows to create user defined materials

• Composite materials, specific density

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Single Particle ICP-MS for Characterization of AgNPs

• Raw data visualization

• Overlay or stack samples even in real time

• Direct data export

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Data Evaluation

• Signal Distribution view

• Identify particle fractions

• Modify particle fraction thresholds

• Statistical Data Evaluation

• Recognize and eliminate artefacts

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Statistical Data Evaluation

• Correct for split particle events*

• Proposal of dilution factor based on filled

slot ratio

• Poisson statistics to assess muliple

particle events

* Liu et al., Anal. Chem. 86 (2014), 3405-3414

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Particle Size and Concentration Evaluation

• Display of all particle fractions per sample

• Calculates mass concentration for

comparison

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Results

• Analysis of NIST 8013

• Au NP with 60nm nominal

diameter

• Result: 58.1 ± 3.0 nm

approx. 21,000 partilces/mL

• Analysis of NIST 8012 in

presence of NIST 8013

• 30 and 60 nm nominal

diameter

• Result 27.4 ± 2.5 nm

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Conclusion

• spICP-MS is straightforward way to characterize

nanoparticles

• Increased detection sensitivity is the key to detect smaller and smaller

nanoparticles

• Easy experimental setup, short analysis time per sample

• The npQuant evaluation module guides the user through

method set-up and aids in data evaluation

• Automated determination of key parameters

• Statistical evaluation of data sets

On the way to routine characterization of Nanomaterials!

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Question and Answer Session