Zhang Lingyi, Wang Zhicong, Zhang Weibing
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
Se Pu. 2013 Feb;31(2):122-6. doi: 10.3724/sp.j.1123.2012.09047.
An ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method was developed for the determination of hydroxycinnamoyltartaric 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 x 2.1 mm, 1.7 microm) at 35 degrees C 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 microg/L with good correlation coefficient (r2 = 0.998 9). The limit of detection was 0.25 microg/L, and the limit of quantification was 25 microg/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 microg/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.
建立了一种超高效液相色谱 - 串联四极杆质谱法（UPLC-MS/MS），用于测定葡萄汁、葡萄皮和葡萄籽中的羟基肉桂酰酒石酸酯，如咖啡酸、对香豆酰酒石酸和阿魏酸。目标分析物在Waters UPLC HSS T3柱（150 mm×2.1 mm，1.7μm）上于35℃分离，采用梯度洗脱，流速为0.3 mL/min。葡萄汁经冷冻离心，上清液用20%甲醇稀释。葡萄皮和葡萄籽样品用80%乙醇提取。提取物通过阀切换技术在分析柱上进行在线净化。流动相为水 - 乙腈（均含0.1%甲酸）。通过负电喷雾电离在多反应监测（MRM）模式下进行MS/MS鉴定和定量。由于缺乏商业标准品，对香豆酰酒石酸和阿魏酸通过咖啡酸当量进行定量。所建立的方法在25 - 2000μg/L范围内具有良好的线性，相关系数良好（r2 = 0.9989）。检测限为0.25μg/L，定量限为25μg/L。在250、750和1200μg/L的加标水平下，咖啡酸的平均回收率在97.7% - 99.5%之间，精密度在2.5%以内。工作溶液在室温下稳定74小时。结果表明，羟基肉桂酰酒石酸酯在葡萄汁、葡萄皮和葡萄籽中的分布存在显著差异。因此，该方法因其简便、快速、回收率好、灵敏度高和准确性高，可用于分析葡萄汁、葡萄皮和葡萄籽中的咖啡酸、对香豆酰酒石酸和阿魏酸。
