Determination of short-chain chlorinated paraffins using comprehensive two-dimensional gas chromatography coupled with low resolution mass spectrometry
Short-chain chlorinated paraffins (SCCPs), recently listed as Persistent Organic Pollutants (POPs) under the Stockholm Convention, are contained in commercial chlorinated paraffin (CP) products, which are used in industries such as metalworking fluids, sealants, and textiles. A novel method to determine SCCPs by comprehensive two-dimensional gas chromatography coupled with low resolution mass spectrometry was developed. Calibration curves of response factor versus chlorine content in two chlorine content ranges (R2 were 0.9544 and 0.9736, respectively) were used for quantification of SCCP total concentration. Moreover, relative concentrations of 24 congener groups were also theoretically calculated. Results showed that this method was able to detect SCCP concentration in commercial CP products and urban air samples. SCCP contribution varied largely among different CP products, which is highly determined by carbon chain distribution in paraffins. SCCP concentration in urban air ranged between 12.8–49.1 ng m−3 during nine-month sampling period. The highest SCCP concentration appeared in summer, and the lowest concentration occurred in winter. Gas phase was dominantly occupied by lighter congeners such as C10 group and Cl6 group, while heavier congeners such as C13 group and Cl7 and Cl8 groups contributed more in particle phase.