磁固相萃取—热脱附—气相色谱—串联质谱检测水中7种多氯联苯

利用氧化石墨烯—四氧化三铁(Fe_3O_4@GO)磁性吸附剂进行磁固相萃取(MSPE),结合在线热脱附—气相色谱—三重四极杆串联质谱系统(TD-GC-MS/MS)建立了一种免有机溶剂的定量检测水中7种指示性多氯联苯(PCBs)的方法。优化了Fe_3O_4@GO的用量、萃取时间及溶液pH等影响磁固相萃取效率的关键因素。在最优条件下,7种PCBs在2~100ng/L内呈良好线性关系,线性相关系数(r)>0.98。检测限(S/N=3)和定量限(S/N=10)分别为0.18~0.40,0.57~1.32ng/L。平均回收率为85.9%~106.2%,相对标准偏差(RSD)为4.0%~13.1%。该方法可用于水样中痕量PCBs污染的快速监测。

Determination of 7 kinds of polychlorinated biphenyls in water by magnetic solid phase extraction/thermal desorption-gas chromatography-tandem mass spectrometry

Magnetic solid phase extraction(MSPE)based on Fe 3O 4-grafted graphene oxide(Fe 3 O 4@GO)was combined with thermal desorption-gas chromatography-tandem mass spectrom-etry(TD-GC-MS/MS)to develop an organic solvent free quantitative analysis method for the determination of 7 kinds of indicative polychlorinated biphenyls(PCBs)in water.The factors affecting the extraction efficiency,induding amount of Fe 3O 4@GO,extraction time and pH value of water sample,were investigated.Under the control of the optimized conditions,an excellent linearity was observed in the range of 2~100 ng/L for the 7 kinds of PCBs,with the correlation coefficients(r)>0.98.The detection limits(S/N=3)and the quantitation limits(S/N=10)were 0.18~0.40 ng/L and 0.57~1.32 ng/L,respectively.The mean recoveries at 2 spiked levels ranged from 85.9%to 106.2%with relative standard deviations(RSD)of 4.0%~13.1%.The proposed method could be used in the monitoring of trace PCBs contaminants in water sample.