LC-MS-MS法测定葡萄中的脱落酸含量

Analysis of abscisic acid content in grape by LC-MS-MS

葡萄中含有较多的糖类、色素和果胶,干扰项较多,对微量脱落酸进行定量分析较为困难。针对此问题,建立了高效测定葡萄中脱落酸含量的LC-MS-MS方法,对提取剂、提取方式、富集净化、色谱条件和质谱条件多个关键环节进行了研究。将葡萄样品粉碎匀浆制成待测样,以甲醇+甲酸(二者体积比为99.5∶0.5)作为提取剂,振荡提取30min,将提取液经MAX Cartridge SPE柱富集净化后进行分析。当上样溶剂为20%~50%(质量分数)的甲醇时,净化洗脱效率较好,能有效去除杂质。色谱条件为ODS2色谱柱(2.1mm×150 mm,5μm),乙腈为A相、质量分数为0.1%的甲酸作为B相流动相,流量为0.2mL/min,梯度洗脱。在负离子监测模式下,选择263.1~153.2作为定性定量离子对,采用标准物质的保留时间和SRM图谱,对照2种方式对样品进行准确定性,外标法以峰面积计算进行定量。结果表明,在19.05~381.00ng/mL范围内线性关系良好,回收率为92.2%~110.4%,RSD值<8.1%,可为高效、快速、准确测定葡萄中的脱落酸含量提供有价值的分析方法。

Grape contains much sugar,pigment and pectin,which has interference and makes it difficult for quantitative analysis of trace abscisic acid.To solve this problem,LC-MS-MS method for the determination of abscisic acid in grape is established.Several key aspects including extractant,extract methods,enrichment,chromatographic conditions and mass spectrometry are studied.The test sample is prepared through pulverization and homogenate of grape sample,and analyzed with methanol+formic acid(V/V=99.5/0.5)as the extractant,after oscillation extraction for 30 min,and with MAX Cartridge SPE as the enrichment and purification extractant.The research shows that the elution efficiency is better and the impurities can be removed effectively when the solvent is methanol of 20% ~50%(mass fraction);the chromatographic condition is of ODS2(2.1 mm×150 mm,5μm)column,acetonitrile as the phase A,0.1%formic acid as mobile phase B,flow rate at 0.2 mL/min,and gradient elution is performed;263.1~153.2 is used as the qualitative-quantitative ion pair in the negative ion monitoring mode,the samples are characterized by the retention time and the SRM atlas,and the external standard method is quantified bythe peak area.The method has a calibration curves of good linearity over the range from 19.05 to 381.00 ng/mL.The recovery rate is 92.2%~110.4%,and RSD is less than 8.1%.This research provides an efficient and accurate method for the determination of abscisic acid in grapes.