建立了固相萃取/液相色谱-串联质谱技术(LC-MS/MS)同时检测橙中2,4-二氯苯氧乙酸、赤霉素、吲哚-3-丁酸、α-萘乙酸、对氟苯氧乙酸、对氯苯氧乙酸和吲哚-3-乙酸7种植物生长调节剂(PGRs)残留量的分析方法.样品经含2％甲酸的乙腈溶液提取,Poly-Sery MAX混合型阴离子交换固相萃取柱净化后,以含4％甲酸的甲醇溶液洗脱,氮吹至近干以1mL乙腈-水(1∶9)溶液定容,采用Phenomenex Gemini-NX 5uC18 110A柱(2.0mm i.d.×1.50 mm,5.0 μm)进行分离,经液相色谱-串联质谱法在多反应监测(MRM)模式下检测,基质匹配溶液外标法定量.结果表明,7种植物生长调节剂在各自范围内线性关系良好,相关系数均大于0.99.7种植物生长调节剂的检出限(S/N＞3)为0.3～3.5 μg/kg,定量下限(S/N＞ 10)为5.4～57.7 μg/kg.空白基质橙在低、中、高3个加标水平下的回收率为79.6％ ～ 110.3％,相对标准偏差(RSDs)为3.1％～10.0％.该方法操作简便、灵敏度高,可满足对瓜果中多种植物生长调节剂残留的分析要求.%A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method with solid phase extraction was developed for the determination of 7 plant growth regulators (PGRs),including 2,4-dichlorophenoxyacetic acid,gibberellic acid,indole-3-butyric acid,α-naphthaleneacetic acid,4-fluorophenoxyacetic acid,4-chlorophenoxyacetic acid and indole-3-acetic acid,in orange.The samples were extracted with acetonitrile (contain 2％ formic acid),and cleaned up on a Poly-Sery MAX.The extract was eluted with 4％ formic acid in methanol,then evaporated with a stream of nitrogen to near dryness,and redissoved with acetonitrile-water(1 ∶ 9).The targeted compounds were separated on a Phenomenex Gemini-NX 5u C1s 110A(2.0 mm i.d.× 150 mm,5.0 μm),and determined by LC-MS/MS under MRM mode with the matrix-matched external standard meth od.The results indicated that the calibration curves were linear in the certain concentration range with correlation coefficients greater than 0.99.The limits of detection (LODs,S/N ＞ 3) were in the range of 0.3-3.5 μg/kg and the limits of quantitation (LOQs,S/N ＞ 10) were 5.4-57.7 μg/kg.The recoveries of 7 PGRs in orange at three spiked levels ranged from 79.6％ to 110.396 with relative standard deviations(RSDs) of 3.1％-10.0％.The established method was simple and sensitive,and could meet the requirements for simultanous analysis of PGRs in amphisarcas.
展开▼
