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

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。

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

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℃. 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 m×0.32 mm×0.25 μ 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 0.9971. 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.