A Method for the Low-Level (ng/g) Determination of Perfluorooctanoate in Carpet by LC—MS—MS Using Matrix Extracted Standards

Fluorotelomer-based acrylic polymers are applied to the surface of carpet to impart oil, stain, and water repellence properties. Concerns that fluorotelomer-based polymers are a possible source of "low level" exposure to humans, coupled with their widespread use have prompted the need to develop a method to detect and measure perfluorooctanoate (PFO) in carpet. A liquid chromatography tandem mass spectrometry method for the determination of PFO in carpet using a dual labeled 13 C-perfluoroctanoic acid ( 13 C-PFOA) internal standard is successfully developed and validated. Levels of PFO are determined using a gradient, reversed-phase high-performance liquid chromatography (HPLC) method with acetic acid acidified water-methanol, separated on a 50 mm Phenomenex Synergi Polar RP column. Ions monitored are 413 (parent) and 369 (daughter) for PFO and 415 (parent) and 370 (daughter) for dual labeled 13 C-PFOA internal standard. Accuracy and precision over three days for 5 to 900 ng/g PFO in carpet ranged from 2.4% to 7.6% and 3.7% to 14.1%, respectively. Overall extraction efficiency for samples (n = 30) fortified with 13 C-PFOA at 20 ng/g and perfluorooctanoic acid (PFOA) at 5, 50, and 500 ng/g is 98.9% ± 8.1%. Specificity of the method was evaluated with two different carpet samples.