基于离子交换色谱法同时测定果酒中8种有机酸

Simultaneous determination of eight organic acids in fruit wine based on ion-exchange chromatography

该研究通过对样品前处理和仪器条件的优化,建立同时测定果酒中8种有机酸的离子交换色谱分析方法。结果表明,样品经稀释和RP柱净化后,经Dionex IonPac AS19色谱柱(4 mm×250 mm)分离,4 mmol/L(0~13 min)和16 mmol/L(14~33 min)氢氧化钾梯度洗脱,采用抑制型电导检测器进行检测,可同时对果酒中奎宁酸、乳酸、乙酸、甲酸、苹果酸、酒石酸、琥珀酸、柠檬酸8种有机酸进行定性和定量分析,8种有机酸标准曲线的相关系数R2在0.996 5~0.998 7之间,检出限为0.82~4.05 mg/L,定量限为2.74~13.5 mg/L,精密度试验结果的相对标准偏差(RSD)均<3%,稳定性试验结果的RSD≤3.65%,加标回收率为82%~125%,加标回收率试验结果的RSD为0.21%~5.13%。该方法操作简便、性能稳定、安全环保,适用于各类果酒的测定。采用该方法对5类市售果酒样品中的8种有机酸进行检测,发现葡萄酒样品主要有机酸成分为乳酸、酒石酸、琥珀酸和乙酸,这四种有机酸的总含量为5 498.50 mg/L;桑葚酒、蓝莓酒、杨梅酒、荔枝酒的主要有机酸均为柠檬酸,其含量在2 888.65~5 730.89 mg/L之间。

Through the optimizing of sample pretreatment and instrument conditions,an ion exchange chromatography analysis method for simultaneous determination of 8 organic acids in fruit wine was established.The samples were diluted and purified by RP column,separated by Dionex IonPac AS19(4 mm×250 mm) column,gradient elution of potassium hydroxide at 4 mmol/L(0-13 min) and 16 mmol/L(14-33 min),and detected by suppressed conductivity detector.The method could qualitatively and quantitatively determine quinic acid,lactic acid,acetic acid,formic acid,malic acid,tartaric acid,succinate acid and citric acid,and the correlation coefficient R2of the standard curve of 8 organic acids were between 0.996 5 and0.998 7,the detection limit was 0.82-4.05 mg/L,the limit of quantification was 2.74-13.5 mg/L,the relative standard deviation(RSD) of the precision tests results was<3%,the RSD of stability tests results≤3.65%,the recovery rate of spike was 82%-125%,and the RSD of the spiked recovery test results was 0.21%-5.13%.The method was simple,stable and eco-friendly,which was suitable for the determination of fruit wine.The method was used to detect 8 organic acids in 5 types of commercially available fruit wine samples.It was found that the main organic acid components of wine samples were lactic acid,tartaric acid,succinic acid,and acetic acid,and the total content of these four acids were 5 498.50 mg/L.The main organic acids of mulberry wine,blueberry wine,waxberry wine and lychee wine were citric acid,and the content were 2 888.65-5 730.89 mg/L.