Solid-phase Extraction for Analysis of Short-chain Chlorinated Paraffins in Water Samples / 分析化学

ABSTRACT

A method for short-chain chlorinated paraffins ( SCCPs) analysis in water samples based on solid-phase extraction ( SPE ) was developed using gas chromatography coupled with electron capture negative chemical ionization mass spectrometry ( GC-ENCI-MS) . SPE parameters including the sorbent, elution solvent and elution volume were optimized. Agilent Bond Elut-C18was precleaned with 3 mL of hexane, 3 mL of methanol and conditioned with 3 mL of H2O before use. After enriched by the cartridge, the sample was washed by 3 mL of methanol (10% , V/V) and eluted by 3 mL of mixture of hexane and dichloromethane (1∶1, V/V). The results showed that the limits of detection ( LOD) of SCCPs were 18 ng/L, and the corresponding limits of quantitation of SCCPs were 60 ng/L. Recovery experiment showed that, for the water samples spiked with 1 μg/L, the recoveries were in the range of 90% -135% and the relative standard deviations were less than ±10% . Finally, the SCCPs in 20 surficial water samples collected in Beijing were analyzed using the method proposed here. The range of the concentrations of SCCPs was ＜LOD to 682 ng/L with a mean concentration of 216 ng/L.