EPA-OW/OST: 1633 (Tissues): Per- and Polyfluoroalkyl Substances (PFAS) in Tissue Samples by LC-MS/MS
|
Official Method Name
|
Draft Method 1633 Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS |
|---|---|
|
Current Revision
| Final version |
|
Media
|
ANIMAL TISSUE |
|
Instrumentation
|
Liquid Chromatography with Tandem Mass Spectrometry |
|
Method Subcategory
|
Organic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
Tissue samples are spiked with isotopically labeled standards, extracted in potassium hydroxide and acetonitrile followed by basic methanol, and cleaned up by carbon and SPE cartridges before analysis. Analyses of the sample extracts are conducted by LC-MS/MS in the multiple reaction monitoring (MRM) mode. Sample concentrations are determined by isotope dilution or extracted internal standard quantification using isotopically labeled compounds added to the samples before extraction. Note revised errata sheet dated February 8, 2022. |
|
Scope and Application
|
The method described here covers the determination of Per- and Polyfluoroalkyl Substances (PFAS) in Tissue Samples. Other methods detailed in EPA 1633 cover the determination of PFAS in Aqueous, Solid, and Biosolids samples. |
|
Applicable Concentration Range
|
As analyzed and uncorrected for original sample mass (2 grams of tissue), ML ranges from 1.6 - 1,560 ng/L but most compounds range 1.6 - 62.5 ng/L. |
|
Interferences
|
(A) Glass equipment: Cleaned by washing with detergent and baking in a kiln or furnace. After detergent washing, glassware should be rinsed immediately with reagent water. Prior to use, baked glassware must be solvent rinsed and then air dried. A solvent rinse procedure using methanolic ammonium hydroxide (1%), toluene, and methanol is recommended. (B) SPE manifold contamination: Cleaned by sonicating in methanolic ammonium hydroxide (1%) and air drying prior to use. Smaller parts, like the needles, adapters, reservoirs, and stopcocks associated with the manifold require rinsing with tap water prior to sonicating in methanolic ammonium hydroxide (1%) and air drying. When in use, after loading the samples but prior to elution procedures, the chamber must be rinsed with methanolic ammonium hydroxide (1%). (C) Tissue filleting, dissecting, shucking, compositing, and homogenization equipment contamination: Clean with detergent and hot water, then rinse with ultra-pure water followed by a series of solvent rinses. A typical solvent rinse procedure would be acetone, followed by toluene, and then dichloromethane. (D) Fluoropolymer interferences: SPE and carbon cleanup are required to remove these compounds. (E) Bile salts (e.g., Taurodeoxycholic Acid [TDCA]) in whole fish interference. Analysis of a standard containing TDCA is required as part of establishing the initial chromatographic conditions. |
|
Quality Control Requirements
|
Extracted Internal Standard (EIS), Non-Extracted Internal Standard (NIS), Native Standards Solution, Calibration standard solutions, Qualitative Standards, Instrument Blank, Sodium iodide/cesium iodide mass calibration solution, Taurodeoxycholic Acid (TDCA) or Sodium taurodeoxychloate hydrate |
|
Sample Handling
|
Fish may be cleaned, filleted, or processed in other ways in the field, such that the laboratory may expect to receive whole fish, fish fillets, or other tissues for analysis. If whole fish are collected, wrap the fish in aluminum foil or food-grade polyethylene tubing, and maintain at 0 - 6 ºC from the time of collection until receipt at the laboratory, to a maximum time of 24 hours. If a longer transport time is necessary, freeze the sample before shipping. Ideally, fish should be frozen upon collection and shipped to the laboratory on dry ice. |
|
Maximum Holding Time
|
90 days at either 0 - 6 ºC or ≤ -20 ºC, no light, with caveat. Extracts - 90 days (0 - 4 ºC, no light, caveat) |
|
Relative Cost
|
|
|
Sample Preparation Methods
|
