液相色谱-串联质谱法快速筛查测定浓缩果蔬汁中的156种农药残留

建立了浓缩果蔬汁中156种农药多残留的液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)测定方法。样品用1%醋酸乙腈溶液萃取,经Waters Sep-Pak Vac固相萃取柱净化,乙腈-甲苯(体积比为3∶1)洗脱,旋转蒸发浓缩,用乙腈-水（体积比为3∶2）溶解，以Agilent ZORBAX SB-C18色谱柱分离,以电喷雾电离串联质谱在正离子多反应监测(MRM)模式下进行测定。对156种农药在5种浓缩果蔬汁(橙汁、苹果汁、葡萄汁、白菜汁、胡萝卜汁)中两个添加水平下的回收率进行了测定,回收率范围为57.2%～122.7%,相对标准偏差范围为0.9%～19.8%。方法的检出限(S/N=3)和定量限(S/N=10)范围分别为0.10～56.77 μg/kg和0.33～189.23 μg/kg。该方法样品前处理简单、快速、分析时间短,灵敏度、准确度和精密度均符合农药多残留检测技术的要求,适用于苹果汁、橙汁、葡萄汁、白菜汁、胡萝卜汁等浓缩果蔬汁中156种农药多残留的快速筛查测定。

Rapid screening and confirmation of 156 pesticide residues in concentrated fruit and vegetable juices using liquid chromatography-tandem mass spectrometry

A multiresidue analytical method was developed for the determination of 156 pesticides in concentrated fruit and vegetable juices using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The pesticide residues were extracted from the samples by acetonitrile containing 1% acetate acid, cleaned-up by a Waters Sep-Pak Vac cartridge, eluted with 25 mL acetonitrile-toluene (3∶1, v/v) and concentrated with a rotary evaporator. The sample was redissolved in the acetonitrile-water (3∶2, v/v), then analyzed using LC-MS/MS in multiple reaction monitoring (MRM) mode via positive electrospray ionization with an Agilent ZORBAX SB-C18 column as the analytical column. The method was validated at two fortification levels in five fruit and vegetable juices, orange, apple, grape, cabbage and carrot juices. The validation results were as follows: The overall recoveries were from 57.2% to 122.7% with the relative standard deviations (RSDs) of 0.9%-19.8%, and the limits of detection (S/N=3) and the limits of quantification (S/N=10) were 0.10-56.77 μg/kg and 0.33-189.23 μg/kg, respectively. The results demonstrated that this method is simple, rapid and characterized with acceptable sensitivity and accuracy to meet the requirements of the multiple pesticide residue analysis. This method is applicable to confirm 156 pesticide residues in the above five juices.