HOLD TIME, STORAGE, AND SAMPLE CONTAINER CONSIDERATIONS

FOR ANALYTICAL METHODS TO DETERMINE HIGHLY FLUORINATED

COMPOUNDS IN ENVIRONMNTAL MATRICES

Mary A. Kaiser1, Million Woudneh2, Barbara S. Larsen1, Michael D. Aucoin3, Kelly A. Rinehimer3, and Richard Grace2

1 DuPont Company, P.O.Box 80402, Wilmington, DE, 19880-0402; 2AXYS Analytical Services Ltd., 2045 Mills Road West, Sidney, B.C. V8L 5X2,

Canada, 3URS Corporation, Barley Mill Plaza 19, Wilmington, DE 19805 USA

ABSTRACTA comprehensive panel of fluorotelomer alcohols, perfluorocarboxylic acids,

and perfluorinated sulfonates were stored in three types of storage containers:

polypropylene, high-density polyethylene (HDPE), and amber glass at common

laboratory storage conditions. Results were measured at intervals from 0 to 90

days to determine hold time guidance and compatible container types. Results

indicate that when stored in appropriate containers and standard laboratory

storage conditions, sample results are not affected for periods up to 90 days.

Amber glass or HDPE containers were determined to be the best storage

containers. Polypropylene containers were deemed to be incompatible

with some perfluorinated carboxylic acids. INTRODUCTION

Fluorotelomer alcohols, perfluorocarboxylic acids and perfluorinated

sulfonates are important highly fluorinated raw materials that have attracted

considerable attention in the last eight years. Many of these compounds have

been found in a variety of environmental matrices and have been reported in many

locations. These compounds have presented considerable analytical challenges.

While considerable analytical work has focused on providing increasingly reliable

results, limited information is available on key issues that affect sample results

such as hold times, storage conditions and sample containers.

EXPERIMENTAL DESIGNFluorotelomer alcoholsHold time study: Matrix = methanol and filter Container types = amber glass jar with polypropylene caps. Hold time intervals = 0, 2, 7, 14, 28, 60 and 90 Days. # of samples analyzed = 3 samples per hold time interval. Storage temperature = -20oC

CONCLUSIONS

USES OF HIGHLY FLUORINATED MATERIALS

Aerospace MaterialsHydraulic tubingWire & Cabling Flares

Chemical Processing

Valves, Lined Piping, Tanks

Semiconductor Manufacture

Health Care Fire Fighting

Carpet & Textiles

MATERIALS

PerfluorocarboxylatesF(CF2)nCO2-

Fluorotelomer alcoholsF(CF2)n CH2CH2OH

Perfluoroalkyl sulfonatesF(CF2)n SO3-

•Note that there is a “perfluorinated” part and an organic functional group.

•Very different physical-chemical properties from each other.

EXPERIMENTAL DESIGNMethod validation for both perfluorinated acids and fluorotelomer alcohols:

•two matrices•three concentrations•triplicate•three different days

Perfluorinated acidsHold time study:

Matrix = reagent water Container types = polypropylene, amber glass, and high- density polyethylene.

Hold time intervals = 0, 2, 7, 14, 28, 60 and 90 Days. # of samples analyzed = 3 samples per hold time interval. Storage temperature = 4oC

METHOD OUTLINE

Fluorotelomer alcoholsQuantitative recovery achieved for 8:2 to 16:2

fluorotelomer alcohols spiked and stored in closed amber glass jars.

Perfluorinated carboxylic and sulfonic acids•Mean percent recovery values of all acid analytes were > 90% after 60 days of storage in amber glass containers. Mean percent recovery values of all acid analytes were > 80% after 90 days of storage in amber glass containers•Mean percent recovery values of all acid analytes were > 70% after 60 days of storage in HDPE containers. Mean percent recovery values of all acid analytes were > 68% after 90 days of storage in HDPE containers. •Up to 28% PFUnA and 34% PFDoA were recovered from polypropylene containers that were used for storing water samples in contact with these perfluorinated acids.

Polypropylene containers are therefore not suitable for sample collection for C11 and C12 perfluorocarboxylic acids.