Analysis of C(14)-C(17) Polychloro-n-alkanes in Environmental Matrixes by Accelerated Solvent Extraction-High-Resolution Gas Chromatography/Electron Capture Negative Ion High-Resolution Mass Spectrometry.

A method for quantifying medium-chain (C(14)-C(17)) polychloroalkanes (mPCAs) in environmental matrixes by accelerated solvent extraction high-resolution gas chromatography/electron capture negative ion high-resolution mass spectrometry in the selected ion monitoring mode is presented. The formula group abundance profiles of industrial mPCA mixtures, which are used as standards, and of samples are first determined by monitoring [M - Cl](-) ions of specific m/z values corresponding to the molecular formulas present and by correcting the integrated ion signals for the fractional abundance of the specific m/z value monitored and the number of chlorine atoms in the formula group. mPCA concentrations in environmental samples are then determined by comparing the response of a specific m/z peak in the sample to that in the standard. Extraction recoveries of mPCAs from spiked fish and sodium sulfate (in place of sediment) were >79%. Method detection limits were 13 ng/g for fish and 1.4 ng/μL for sediment, while the analytical detection limit was ∼200 pg, at a signal-to-noise ratio of 4:1. By this method, mPCAs were detected in biota and sediment from the mouth of the Detroit River (MI) and ranged from 70 to 900 ng/g. The simultaneous quantitation of C(10)-C(13) (sPCAs) and C(14)-C(17) PCAs, based on monitoring two specific m/z peaks, one characteristic of sPCAs and the other of mPCAs, is also demonstrated.