高效液相色谱串联质谱法同时测定水稻中丙炔(口恶)草酮、吡氟酰草胺和二甲戊灵的残量

目的]建立了在水稻植株、稻壳和糙米中同时测定丙炔口恶]草酮、吡氟酰草胺和二甲戊灵3种农药的高效液相色谱串联质谱分析方法,为我国制定吡氟酰草胺在糙米上的最大残留限量提供数据依据,同时为这3种农药在水稻植株、糙米和稻壳上的残留监测提供依据。方法]样品通过含甲酸的乙腈提取,QuEChERS法净化,C18色谱柱分离,以(0.1%甲酸+5 mmol/L乙酸铵)水-甲醇为流动相进行梯度洗脱,高效液相色谱串联质谱分析。结果]丙炔口恶]草酮、吡氟酰草胺和二甲戊灵在植株中的添加水平为0.01、0.1、0.5 mg/kg,在稻壳和糙米中的添加水平为0.005、0.01、0.1、0.5 mg/kg,丙炔口恶]草酮水稻植株、稻壳和糙米的平均回收率分别为88.2%~98.7%、74.1%~88.2%和92.4%~97.8%,相对标准偏差分别为1.7%~4.6%、2.3%~5.8%、1.5%~4.8%;吡氟酰草胺在水稻植株,稻壳和糙米的平均回收率分别为90.3%~99.0%、78.1%~96.0%和92.8%~97.9%,相对标准偏差分别为1.0%~4.8%、4.4%~6.6%、1.4%~4.6%;二甲戊灵在水稻植株,稻壳和糙米的平均回收率分别为88.0%~94.5%、89.1%~98.1%和90.6%~92.6%,相对标准偏差分别为2.6%~4.5%、2.5%~4.8%、1.9%~5.6%。该方法中丙炔口恶]草酮、吡氟酰草胺和二甲戊灵最低检出限分别为0.01、0.005、0.005 mg/kg。结论]该方法灵敏度、准确度、精密度能满足水稻中丙炔草酮、吡氟酰草胺和二甲戊灵的残留检测要求,而且快速简便。

Multi-Residue Determination of Oxadiargyl,Diflufenican, and Pendimethalin in Rice by HPLC-MS/MS

Aims] A new method for analysis of oxadiargyl, diflufenican and pendimethalin residues in rice plants, rice husks and brown rice by high performance liquid chromatography-tandem mass spectrometry was developed to provide data support for the maximum residue limit for diflufenican on brown rice, and to provide basis for monitoring the residue of these three pesticides on rice plants, brown rice and rice husk. Methods] The sample was extracted with acetonitrile containing formic acid, purified by Qu ECh ERS method, separated by reversed phase C18 column, and eluted with(0.1% formic acid+5 mmoL ammonium acetate) water: methanol as mobile phase. Finally, the samples were detected by high performance liquid chromatography-tandem mass spectrometry. Results] The levels of addition of oxadiargyl, diflufenican and pendimethalin in the plants were 0.01, 0.1 and 0.5, and the levels of addition of oxadiargyl,diflufenican and pendimethalin in rice husks and brown rice were 0.005, 0.01, 0.1 and 0.5. The average recoveries of oxadiargyl in rice plants, rice husk and brown rice were 88.2-98.7, 74.1-88.2 and 92.4-97.8%, with the relative standard deviations of 1.7-4.6, 2.3-5.8 and 1.5-4.8%, respectively. The average recoveries of diflufenican in rice plants, rice husk and brown rice were 90.3-99.0, 78.1-96.0 and 92.8-97.9%, with the relative standard deviations of 1.0-4.8, 4.4-6.6 and1.4-4.6%, respectively. The average recoveries of pendimethalin in rice plants, rice husk and brown rice were 88.0-94.5,89.1-98.1 and 90.6-92.6%, with the relative standard deviations of 2.6-4.5, 2.5-4.8 and 1.9-5.6%, respectively. The minimum detection concentrations of oxadiargyl, diflufenican and pendimethalin were 0.01, 0.005, 0.005 mg/kg,respectively. Conclusions] The method is simple and reliable, besides, the sensitivity, accuracy and precision of the method can meet the requirements of pesticide residue analysis, which can be applied for analysis of oxadiargyl,diflufenican and pendimethalin residues in rice.