基于固相萃取-响应面优化的碳骨架在线催化/GC-MS/MS技术测定含油金属原料表面痕量氯污染物

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

采用碳骨架在线催化/气相色谱-串联质谱(Online catalytic/GC-MS/MS)技术建立了进口含油金属原料中多氯联苯(PCBs)、多氯萘(PCNs)、短链和中链氯化石蜡(SCCPs、MSCCPs)等含氯污染物的测定方法,考察了固相萃取(SPE)条件,研究了催化剂的制备、在线催化温度、氢气流速及氯化程度等对催化效率的影响,并运用三维响应面法优化催化条件。样品通过自制催化衬管在线脱氯加氢,目标物经催化后转化为碳骨架不变的正构烷烃和芳烃化合物,采用多反应监测模式进行检测。10种还原产物在0.02~1.00μg/mL质量浓度范围内与其对应的峰面积呈线性关系,方法定量下限为0.26~5.33μg/kg。样品的加标回收率为87.2%~111%,相对标准偏差(RSD,n=6)不大于7.1%。该方法催化快速、灵敏度高、准确性好,无需化学电离源或高分辨气相色谱-质谱仪即能达到较低的检出限,适用于含油金属原料中氯污染物的测定。

A gas chromatography-tandem mass spectrometry with online catalysis was established for the determination of polychlorinated biphenyls(PCBs),polychlorinated naphthalene(PCNs),shortchain 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 selfmade 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 μg/mL.The limits of quantitation were 0.26-5.33 μg/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.