3种方法测定植物源性农产品中(噁)霉灵残留量

摘要

建立了测定大豆、糙米、黄瓜、甜菜等6种植物源性农产品中(噁)霉灵残留的气相色谱-火焰光度法(GC-FPD)、气相色谱-氮磷检测法(GC-NPD)和液相色谱-串联质谱法(LC-MS/MS).GC-FPD法采用丙酮-正己烷提取样品,O,O-二甲基硫代磷酰氯衍生,GC-FPD分析,外标法定量;GC-NPD法采用丙酮-正己烷提取样品,十八烷基键合硅胶(C18)净化,GC-NPD分析,外标法定量;LC-MS/MS法,样品采用乙腈提取,石墨化碳黑(GCB)净化,LC-MS/MS分析,基质匹配外标法定量.结果表明,(噁)霉灵的响应值与其浓度间呈良好的线性关系,3种方法的相关系数均大于0.998.在3个加标浓度下,GC-FPD法中(噁)霉灵的日间平均回收率为82%~96%,日间相对标准偏差(RSD)为3.4%~12.1%,方法的定量下限为0.25 mg/kg (甜菜为0.05 mg/kg);GC-NPD法的日间平均回收率为81%~103%,日间RSD为4.1%~14.3%,定量下限为0.25 mg/kg (甜菜为0.05 mg/kg);LC-MS/MS法的日间平均回收率为74%~110%,日间RSD为2.5%~10.7%,定量下限为0.05 mg/kg.3种方法均具有良好的准确性和稳定性,可满足(噁)霉灵残留分析的要求.%Three analytical methods were developed for the determination of hymexazol residues in 6 kinds of plant-derived agro-products(e.g.soybean,rice,cucumber,beetroot,cole and tomato) by gas chromatography with a flame photometric detector(GC-FPD),gas chromatography with a nitrogen-phosphorus detector(GC-NPD) and liquid chromatography tandem mass spectrometry(LC-MS/MS) ,respectively.In GC-FPD,samples were extracted with acetone-hexane.The extracts were derivated with dimethylthiophosphoryl(DECTP),and then determined by GC-FPD,and quantified by the external standard method.In GC-NPD,samples were extracted with acetone-hexane.The extracts were purified with octadecylsilane(C18) sorbent,and then determined by GC-NPD,with quantitation by the external standard method.In LC-MS/MS,samples were extracted with acetonitrile.The extracts were purified with graphitized carbon black(GCB) sorbent,and then determined by LC-MS/MS with quantitation by the matrix-matched calibrations.The calibration curves of three methods all showed good linearities,with correlation coefficients(r2) more than 0.998.At three spiked concentration levels,the inter-day average recoveries of hymexazol were found to be in the range of 82%-96% for GC-FPD method with relative standard deviations(RSDs) of 3.4%-12.1%,81%-103% for GC-NPD method with RSDs of 4.1%-14.3% and 74%-110% for LC-MS/MS with RSDs of 2.5%-10.7%.In GC-FPD and GC-NPD,the limits of quantitation(LOQ) in beetroot were 0.05 mg/kg,and LOQs of other five matrices were 0.25 mg/kg.In LC-MS/MS,LOQs of 6 matrix were all 0.05 mg/kg.Three methods are accurate,and could meet the detection requirements of hymexazol residue in plant-derived agro-products.