A novel method for quantifying short- and medium-chain chlorinated paraffins using comprehensive two-dimensional gas chromatography-high-resolution mass spectrometry.

Due to the complex composition of chlorinated paraffins (CPs), the analysis is extremely difficult since they contain thousands of isomers and homologues. Though many methods have been developed in recent years, simple and accurate quantitative method is still lacking. Here we proposed a new method for determining the composition pattern of short-chain and medium-chain chlorinated paraffin homologues (CnClm), and calculate the response factor (RF) of each congener group. In this study, 24 different chain length standards were analyzed by comprehensive two-dimensional gas chromatography-electron capture negative ionization high-resolution mass spectrometry (GC × GC-ECNI-HRMS). As previous studies have already shown that relative amounts of each CnClm with fixed carbon chain length almost exhibited a Gaussian curve in commercial CP mixture standards, the RF of each CnClm was then calculated according this discovery. This method was verified by determining the congener group patterns of SCCP mixtures and MCCP mixtures, and the congener group patterns were consistent with the manufacturer-reported chlorination degrees. Compared with other quantitative methods, this method does not require complex derivatization or mathematical calculations, thus provides a new approach for the detection of chlorinated paraffins.