The quantification of chlorinated paraffins in environmental samples by ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry

As high-production-volume chemicals, chlorinated paraffins (CPs) have raised an increasing environmental concern in recent years. However, their accurate analysis and quantification is still a huge challenge due to the high complexity of their technical formulations and the interference from CPs congeners and other polychlorinated products. In this study, a novel method for the simultaneous analysis of short-chain (SC) and medium-chain (MC) CPs in a single injection has been developed using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry (UHPLC-Orbitrap Fusion TMS). Compared with other analytical methods for CPs, this novel method can greatly shorten the measurement time and provides a lower limit of detection. A high resolution of 120,000 FWHM was set to avoid the self-interference of CPs congeners and to eliminate interferences from chlorinated olefins (COs). Accuracies for SCCPs and MCCPs standards were evaluated at 75-103% and 83-118%, respectively. The developed method was further validated by determining CPs in sediment, soil, and indoor dust samples. This novel method gives higher CPs concentrations than those achieved by gas chromatography-electron capture negative ionization low-resolution mass spectrometry (GC-ECNI-LRMS), with factors of 1.1-12.5 for SCCPs and 0.7-2.7 for MCCPs, respectively. Some new CPs, such as C₈Cl_7-8 and C₉Cl_5-8, have been determined in soil samples for the first time, indicating great potential of this novel method for routine CP analysis in various environmental samples.