Determination of Trace Chlorine Pollutants in Oil-bearing Metal Raw Materials by Gas Chromatography£­Tandem Mass Spectrometry with Solid Phase Extraction£­Response Surface Optimized Carbon Skeleton Online Catalysis

KeyWord:online catalysis  hydrodechlorination  gas chromatography£­tandem mass spectrometry  chlorine pollutants  oil-bearing metal raw materials

Abstract:

      A gas chromatography£­tandem mass spectrometry with online catalysis was established for the determination of polychlorinated biphenyls£¨PCBs£©£¬polychlorinated naphthalene£¨PCNs£©£¬short-chain chlorinated paraffins£¨SCCPs£© and medium-chain chlorinated paraffins£¨MSCCPs£© in imported oil-bearing metal raw materials£®The pretreatment conditions for solid phase extraction£¨SPE£© were investigated£¬and the effects of catalyst preparation£¬catalytic temperature£¬hydrogen flow rate and chlorination degree on the catalytic efficiency were investigated£®And the catalytic conditions were optimized by response surface method£®The samples were online dechlorinated and hydrogenated by self-made catalytic device£®The target compounds were converted into n-alkanes and aromatic hydrocarbons with unchanged carbon framework after catalysis£¬and detected in multi-reaction monitoring mode£®The calibration curves for ten reduction products were linear in the range of 0.02£­1.00 ¦Ìg/mL£®The limits of quantitation were 0.26£­5.33 ¦Ìg/kg£®The recoveries ranged from 87.2% to 111%£¬with the relative standard deviations£¨RSDs£© not more than 7.1%£®The method is simple£¬accurate and reliable£¬and it could achieve a low detection limit with no need of GC£­CI£­MS or HRMS£®Therefore£¬it is suitable for the determination of chlorine pollutants in imported oil-bearing metal raw materials.