Solid-phase Extraction for Analysis of Short-Chain Chlorinated Paraffins in Water Samples

A method for analysis of short-chain chlorinated paraffins (SCCPs) in water based on solid-phase extraction (SPE) was established using electron capture negative chemical ionization mass spectrometry (GC-ENCI-MS). The SPE parameters, including the sorbent, eluent and elution volume were optimized. The Agilent Bond Elut-C-18 was precleaned with 3 mL of hexane and 3 mL of methanol, and subsequently conditioned with 3 mL H2O prior to use. After the water samples were enriched by the cartridge, the sample was washed with 3 mL of 10% (V/V) methanol and eluted with 3 mL of hexane-dichloromethane (1:1, V/V) solution. The results indicated that the limits of detection (LOD) for SCCPs were 18 ng L-1, while the corresponding limits of quantitation (LOQ) were 60 ng L-1. The spiked recovery range was 90%-135%, with a relative standard deviation of less than 10%. Finally, 20 surficial water samples around Beijing were collected and SCCPs contents were analyzed using the proposed method. The SCCPs concentrations ranged from less than LOD to 682 ng L-1 with a mean concentration of 216 ng L-1.