Standard Test Method for Determination of Fluorotelomer Alcohols in Test Chamber Air by Thermal Desorption-Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometry (TD-GC-MS/MS)

Importancia y uso:

5.1 FTOHs are volatile and semivolatile precursors to perfluorinated carboxylic acids and are used in the synthesis of various surfactants and as intermediates in the manufacturing of a variety of consumer products including polymers, paints, adhesives, aqueous film-forming foam, waxes, and cleaning agents (1, 2).6 The residential indoor air burden of FTOHs from consumer products, building materials, and household dust is not well understood as there are limited emission data available (1-4).

5.2 The indoor environment can be one of the primary pathways for general population exposure to PFAS, including FTOHs, due to direct (that is, skin contact or ingestion) or indirect exposure (that is, inhalation of suspended particles and gases) to chemicals in consumer products and building materials (3-5).

5.3 Validated analytical methods to characterize FTOHs in test chamber air are necessary as the initial step for conducting human exposure assessments using mass-transfer models and other techniques.

5.4 The scope of this test method may expand to other types of air samples, in particular indoor air samples, as data becomes available.

5.5 FTOHs have previously been quantified using liquid chromatography-mass spectrometry (LC-MS) (6-8); however, targeted analysis using gas chromatography-mass spectrometry (GC-MS) is preferred due to sensitivity limitations arising from ionization with LC-MS and from adduct formation when LC-MS chromatographic conditions are optimized for concomitantly quantifying other PFAS (1, 2, 9-17).

5.6 Sampling with TD tubes can be performed passively using diffusion caps or actively using a pump/forced air. This increases the flexibility of the sampling and analytical method because a wide range of air volumes can be collected (~500 mL to ~500 L), which in turn increases the range of concentrations which can be assessed. TD tube sampling also eliminates the variability of solvent extraction recovery. TD tubes are desorbed and preconcentrated with an appropriate TD apparatus, and the sample is then immediately transferred to a GC column for separation and analysis; thus, minimizing the potential for sample loss or contamination and significantly increasing sensitivity to FTOHs (2, 14-19).

5.7 GC-MS/MS is used in this standard to quantify trace levels of FTOHs in test chamber air because of its ability to obtain precursor-to-product mass fragmentation spectra via MRM and because its higher sensitivity and selectivity compared to GC-single quadrupole MS or LC-MS. This analytical approach improves reliability and detectability of measuring FTOHs in air samples, especially for sampling methods that involve large air volumes or complex matrices (12, 18, 19).

Subcomité:

D22.05

Referida por:

F3700-25

Volúmen:

11.07

Número ICS:

71.080.60 (Alcohols. Ethers)

Palabras clave:

consumer products; emissions; fluorotelomer alcohols; gas chromatography-tandem mass spectrometry; PFAS; thermal desorption;