固相萃取/液相色谱-串联质谱对瓜果中7种植物生长调节剂残留的测定

Determination of 7 Plant Growth Regulator Residues in Orange by Solid Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry

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1 mL乙腈-水(1∶9)溶液定容,采用Phenomenex Gemini-NX 5uC18110A柱(2.0 mm i.d.×150 mm,5.0μm)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0.3～3.5μg/kg,定量下限(S/N>10)为5.4～57.7μg/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-naphthaleneacetie 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 C18 l10A（2. 0 mm i.d. x 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, The recoveries of 7 PGRs in orange at three spiked levels ranged S/N〉 10） were 5.4 -57.7 μg/kg. from 79. 6% to 110. 3% with relative standard deviations（RSDs） of 3.1% -10. 0%. The established method was simple and sensitive, and could meet the requirements for simuhanous analysis of PGRs in amphisarcas.