气相色谱-脉冲火焰光度法测定水产品中的二硫氰基甲烷残留

Determination of methylene bisthiocyanate in aquatic products by gas chromatography with pulsed-flame photometric detector

建立了气相色谱-脉冲火焰光度法(GC-PFPD)测定水产品中二硫氰基甲烷(MBT)残留的分析方法。用二氯甲烷-正己烷溶液(1∶1,v/v)在超声条件下提取水产品中的MBT,然后用中性氧化铝固相萃取小柱对提取物进行净化和富集,通过HP-5MS石英毛细管柱(30 m×0.32 mm×0.25μm)分离,最后采用配有脉冲火焰光度检测器的气相色谱仪进行测定,外标法定量。MBT在1.0~20.0 mg/L范围内线性关系良好,相关系数为0.997 1;检出限为0.1 mg/kg;加标回收率为65.6%~97.6%,精密度为6.32%~12.8%(n=7)。该法能很好地满足水产品中药物残留检测的需求。

A novel method was developed for the determination of methylene bisthiocyanate (MBT) in aquatic products by gas chromatography with pulsed. flame photometric detector (GC-PFPD). The samples were extracted by dichloromethane-n-hexane (1:1, v/v), concentrated and cleaned up by neutral. alumina SPE cartridges. The extracts were eluted with 8 mL dichloromethane, and blown to dryness by nitrogen at 35 degrees C. The final extracts were redissolved with a mixture of dichloromethane-n-hexane (1:1, v/v), separated by an HP-5MS quartz capillary column (30 mx0.32 mmx0.25 mu m) and detected by PFPD with external standard method. Under the optimum experimental conditions, the standard curve was linear in the range of 1.0-20.0 mg/L with correlation coefficient of 0.997 1. The limit of detection was 0.. 1 mg/kg. Recoveries ranged from 65.6% to 97.6% with RSDs of 6.32% - 12.8% (n = 7). The method has good innovative, advanced and practical values.