Page 7 - Food&Beverages PFAS_analysis
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Preparing Samples
LABORATORY MATERIALS
Preparation and Storage
of Stock Solutions and Standards
Stock solutions should be prepared and stored in PFAS-free high-density
polyethylene (HDPE) or polypropylene (PP) containers with lined or unlined
HDPE or polypropylene caps. Do not store samples in containers made
of glass or low-density polyethylene (LDPE) materials. PFAS can adsorb to
glass, especially when the chemicals are stored in a glass container for
long periods of time.
Stability of the standards solutions for a predetermined interval of time
when stored under recommended conditions is a relevant parameter for
ensuring the quality of the analysis. As shown in Figure 1 (see next page),
50% methanol in water (same mixture as that used in ASTM D7979) is the
optimal solution for dissolving PFAS and maintaining them in solution.
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