高效液相色谱-串联质谱法测定水果中多种天然植物生长调剂的残留量

Determination of several natural plant growth regulators in fruits by high performance liquid chromatography-tandem mass spectrometry

目的采用高效液相色谱-串联质谱法建立了同时测定水果中赤霉素GA3、吲哚-3-乙酸和1-萘乙酸3种天然植物生长调剂残留的检测方法。方法样品经QuEChERS法进行预处理,以1%乙酸乙腈提取,无水硫酸镁和C18粉末净化。选用水-乙腈为流动相,C18色谱柱分离,采用Agilent AJS ESI源、负离子扫描和多反应检测模式(MRM)进行质谱检测,基质匹配标准溶液外标法定量。结果 3种天然植物生长调剂在0.005～1.000mg/L浓度范围内线性关系良好,赤霉素GA3的方法定量限(S/N=10)分别为0.010 mg/kg,吲哚-3-乙酸和1-萘乙酸均为0.005 mg/kg。对空白水果样品进行0.020、0.050、0.100 mg/kg 3个添加水平的回收实验,赤霉素GA3、吲哚-3-乙酸和1-萘乙酸的回收率分别为75.4%～109.8%、79.1%～109.3%和79.6%～112.9%,相对标准偏差(n=6)分别为3.5%～17.4%、6.5%～15.8%和4.8%～13.9%。结论该方法快速简便,定量准确,可满足水果中3种农药的残留检测要求。

Objective To develop a method for the simultaneous detection of GA3, IAA and NAA in fruits by QuEChERS-HPLC-ESI-MS/MS. Methods The samples were extracted with acetonitrile with 1%acetic acid, purified using powder of magnesium sulfate and C18. Three pesticides were separated on a C18 column with the mobile phases of water and acetonitrile and finally detected with negative electrospray io-nization in MRM mode. The matrix-matched external standard calibration curves were used for quantitative analysis. Results The linearities of GA3, IAA and NAA were in the concentration ranges of 0.005～1.000 mg/L, with the correlation coefficients higher than 0.9990 for the 3 pesticides. The limit of quantification (LOQ) were 0.010 mg/kg for GA3, 0.005 mg/kg for IAA and NAA. For all the samples, the mean spiked re-coveries of GA3, IAA and NAA ranged from 75.4%～109.8%, 79.1%～109.3% and 79.6%～112.9%, respec-tively, and the relative standard deviations (RSD, n=6) were in the range of 3.5%～17.4%, 6.5%～15.8% and 4.8%～13.9%, respectively. Conclusion The method is quick, easy, effective, sensitive and accurate, and it can meet the requirements for the determination of GA3, IAA and NAA pesticide residues in fruits.