UPLC-MS/MS法同时测定生菜叶片中五种植物内源激素

Simultaneous Determination of Five Plant Endogenous Hormones in Lettuce Leaves by Ultra High Performance Liquid Chromatography-tandem Mass Spectrometry

以有机生菜为试材,采用甲醇∶甲酸∶水=15∶1∶4作为提取剂,经过超声、离心、氮吹,DiKMA ProElut PXA固相萃取柱分离纯化后得到植物激素提取液,在38℃恒温水浴中氮吹浓缩干燥,甲醇作为复溶液进行复溶,得到植物激素待测液。采用ACQUITY UPLC BEN反相色谱柱(2.1 mm×100 mm,1.7μm)对5种植物激素进行分离,流动相A为0.1%甲酸水溶液,流动相B为甲醇溶液,梯度洗脱,流速为0.30 mL·min^(-1),柱温为40℃;在液相色谱质谱联用多反应监测(MRM)模式下进行定性定量分析,外标法测定植物激素回收率。建立了应用超高效液相色谱-串联质谱(UPLC-MS/MS),同时测定叶菜类蔬菜中赤霉素、生长素、脱落酸、水杨酸、茉莉酸5种植物内源激素含量的方法,并优化了生菜基质中激素的前处理方法、质谱色谱条件等。结果表明:生菜在低、中、高浓度加标时,5种激素的加标回收率为60.15%~107.73%,且相对标准偏差均小于7.6%,检出限为0.30~0.52μg·kg^(-1),定量限为0.68~1.56μg·kg^(-1)。该方法快速灵敏,可适用于其它叶菜类植物中赤霉素、生长素、水杨酸、茉莉酸、脱落酸含量的检测,以期为叶菜类植物叶片中多种内源激素的同时检测提供了一个快速有效的方法。

Organic lettuce sample was ground in liquid nitrogen and placed in the extractant(v/v,methanol∶formic acid∶water ratio of 15∶1∶4)followed by ultrasonic,centrifugation,nitrogen blowing,and purification with the DiKMA ProElut PXA solid phase extraction column.The extract was concentrated and dried in vacuum at 38℃,then redissolved with methanol.Chromatographic separation of 5 types of plant hormones was performed using an ACQUITY UPLC BEN reverse-phase chromatography column(2.1 mm×100 mm,1.7μm).Phase A(0.1%formic acid solution)and Phase B(methanol solution)of UPLC-MS/MS were used to conduct gradient elution at a constant flow rate of 0.30 mL·min^(-1) at 40℃.Qualitative and quantitative analysises were carried out in multiple-reaction monitoring(MRM)mode,and the recovery rates of plant hormones were calculated with external standard.A method was established for the simultaneous determination of gibberellin,auxin,abscisic acid,salicylic acid and jasmonic acid in leafy vegetables using ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)in this study.Additionally,the method for purifying hormones in the lettuce matrix and mass spectrometry conditions were optimized.The results showed that the spiked recovery rates of five types of hormones ranged from 60.15%to 107.73%,and all the relative standard deviations were less than 7.6%when lettuce was spiked with low,middle,and high concentrations.Further,the detection limit and the limit of quantification ranged from 0.30μg·kg^(-1) to 0.52μg·kg^(-1) and 0.68μg·kg^(-1) to 1.56μg·kg^(-1),respectively.This efficient and sensitive method will be used to detect gibberellin,auxin,salicylic acid,jasmonic acid,and abscisic acid in other leafy vegetables.