优化高效液相色谱-串联质谱法检测水产品中孔雀石绿及隐色孔雀石绿的残留量

Optimization of methods for determination of malachite green and leucomalachite green in aquatic products by high performance liquid chromatography-tandem mass spectrometry

目的对GB/T 19857-2005中检测水产品中孔雀石绿及隐色孔雀石绿残留量的高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)进行优化。方法经匀质的水产品样品,加20 mL乙腈和5 g酸性氧化铝旋涡振荡,取4 mL提取液,35℃水浴氮吹近干,用7:3(V:V)乙酸铵和乙腈混合溶液1 mL定容,过0.22μm滤膜。样液用HPLC-MS/MS进行检测,以氘代孔雀石绿和氘代隐色孔雀石绿为内标物进行定量。结果本实验的线性范围在0.5~10.0μg/kg,相关系数为0.9994和0.9995,孔雀石绿和隐色孔雀石绿的平均检出限达到0.0241μg/kg和0.0475μg/kg,方法的回收率在91.1%~107.3%之间,相对标准偏差在1.0%~10.4%之间。结论该方法灵敏度高,准确性好,与GB/T 19857-2005相比,简化了前处理步骤,回收率稳定。通过验证,该方法适用于开展水产品中孔雀石绿及隐色孔雀石绿残留的检测。

Objective To optimize the method in GB/T 19857-2005 of determination of malachite green （MG） and leucomalachite green （LMG） residues in aquatic product by high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. Methods A total of 20 mL acetonitrile and 5 g acid alumina were added into homogeneous aquatic samples, then they were thoroughly vortex oscillated. About 4 mL of extracted liquid was dried by nitrogen under 35℃ water bath, then it was fixed capacity to 1 mL by adding ammonium acetate and acetonitrile solution （7：3, V：V）. Then they were filtered by 0.22 μm filter membrane. The sample solution was separated by HPLC-MS/MS, and the contents were quantitatively carried out by deuterium malachite green （MG-D5） and deuterium leucomalachite green （LMG-D6）. Results The linear ranges of the experiment were from 0.5μg/kg to 10 μg/kg, and the correlation coefficients were 0.9994 and 0.9995, respectively. The average limits of detection of malachite green and leucomalachite green were 0.0241 μg/kg and 0.0475 μg/kg, respectively. The recoveries were 91.1%-107.3%, and the relative standard deviations were 1.0%-10.4%. Conclusion Compared with the existing national standard, the established method is sensitive and accurate, and the pretreatment steps are simplified and the recovery rate is stable, which is suitable for determination of malachite green and leucomalachite green residues in aquatic products.