Determination of Short-Chain Polychlorinated Paraffins in Fish Samples by Short-Column GC/ECNI-MS

A new analytical method has been developed for quantification of C10−C13 polychlorinated paraffins in fish samples. After a cleanup procedure with a silica gel minicolumn and gel permeation chromatography, detection has been achieved by a short-column gas chromatography/electron capture negative ion mass spectrometry. The quantification was performed by reintegration of selected ions from full-scan spectra. Without chromatographic separation, all short-chain polychlorinated paraffins eluated from the column as only one peak. Consequently, this leads to better sensitivity and makes it more easy to survey the spectra. For the first time, a great number of C10, C11, C12, and C13 polychlorinated alkanes with different chlorine contents were used as standards. Detection limits in the full-scan mode varied between 10 and 100 pg depending on the chlorination grade of the alkanes. The results show, that polychlorinated decanes are the dominant residues in the most of investigated fish samples.