Resolving mass fractions and congener group patterns of C8−C17 chlorinated paraffins in commercial products: Associations with source characterization

Highlights: • Mass fractions and profiles of 57 C₈ − C₁₇ CPs were resolved by GC × GC–ECNI-HRTOFMS. • vSCCPs including C₈Cl_5–8 and C₉Cl_5–9 CPs were identified in commercial products. • C₈ − C₁₇ CP congener group abundances varied among different CP-52 products. • Source association of C₈ − C₁₇ CPs were found between CP-52 and environment samples. Commercial chlorinated paraffins (CPs) are a source of CPs in the environment, and clarification of the different CP groups present in commercial products is important for source characterization. Resolving CP congener groups is hindered by the complex CP compositions of commercial products. We used comprehensive two-dimensional gas chromatography coupled with electron capture negative ionization high-resolution time-of-flight mass spectrometry to profile 57 C₈ − C₁₇ CP congener groups in 18 CP-42, CP-52, and CP-70 commercial products. Very short-chain CPs (vSCCPs), including C₈Cl_5–8 and C₉Cl_5–9 CPs, and other chlorinated aromatic compounds were identified in the commercial products. The mass fractions of total vSCCPs, short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in the commercial products ranged from 0.02% to 3.61%, 0.75% to 51.4%, and 0.39% to 69.1%, respectively. Two-dimensional hierarchical cluster analysis with a heat map plot highlighted variations in the C₈ − C₁₇ CP congener group patterns among different commercial CP formulations. The principal component analysis results indicated that commercial CPs products might be important contributors to vSCCPs, SCCPs, and MCCPs in various environmental matrices. This study provides comprehensive and well-resolved compositional data for CPs in commercial products, which will be helpful for CP source characterization.