An ultra-high performance liquid chromatography-tandem quadrupole mass spec-trometry (UPLC-MS/MS) method was developed for the determination of hydroxycinnamoyltar-taric esters, such as caftaric acid, p-coutaric acid and fertaric acid in grape juice, peel and seed. The target analytes were separated on a Waters UPLC HSS T3 column (150 mm × 2. 1 mm, 1. 7 μm) at 35 ℃ with gradient elution at a flow rate of 0. 3 mL/min. The grape juice was freeze-centrifuged, the supernatant was diluted with 20% methanol. The grape peel and grape seed samples were extracted with 80% ethanol. The extract was cleaned-up on-line with the analytical column by valve switching technology. The mobile phases were water-acetonitrile (both containing 0. 1% formic acid). The identification and quantification were achieved by MS/MS in multiple reaction monitoring (MRM) mode via negative electrospray ionization. As lack of commercial standards, p-coutaric acid and fertaric acid were quantified by caftaric acid equivalent. The developed method showed a good linearity over the range of 25 - 2 000 μg/L with good correlation coefficient (r2 =0. 998 9). The limit of detection was 0. 25 μg/L, and the limit of quantification was 25 μg/L. The average recoveries of caftaric acid were between 97. 7% -99. 5% and the precisions were within 2. 5% at the spiked levels of 250, 750 and 1 200 μg/L. The working solutions were stable for 74 h at room temperature. The results showed that there are significant differences of hydroxycinnamoyltartaric esters distribution in grape juice, peel and seeds. Therefore, this method, owing to its simplicity, rapidity, good recovery, high sensitivity and accuracy, can be used for the analysis of caftaric acid, p-coutaric acid and fertaric acid in grape juice, peel and seeds.%建立了超高效液相色谱-串联四极杆质谱测定葡萄汁、皮和籽中羟基桂皮酒石酰酯类化合物含量的方法.采用的色谱柱为Waters UPLC HSS T3(150 mm×2.1 mm,1.7μm),流动相为含0.1％甲酸的水-乙腈体系,梯度洗脱,流速0.3 mL/min,柱温35℃；质谱采用电喷雾离子源、负离子多反应检测模式.对单香豆酰酒石酸酯和单阿魏酰酒石酸酯,其含量以单咖啡酰酒石酸酯当量表示.结果表明,单咖啡酰酒石酸酯在25 ～2 000 μg/L范围内线性关系良好(r2=0.998 9)；检出限为0.25 μg/L,定量限为25 μg/L;在250、750、1 200 μg/L添加水平下单咖啡酰酒石酸酯的平均回收率为97.7％～99.5％,相对标准偏差小于2.5％.实验结果表明,葡萄汁、皮和籽中羟基桂皮酒石酰酯类化合物的含量差异显著.该方法简单快速、灵敏度高、回收率高、准确性好,可用于葡萄产品中单咖啡酰酒石酸酯、单香豆酰酒石酸酯和单阿魏酰酒石酸酯的分析.
展开▼
