【摘要】 目的建立了离子色谱-质谱联用技术测定葡萄酒样品中柠檬酸的分析方法。方法以高容量、强亲水性的IonPac AS20型阴离子交换柱为分析柱,EGC在线产生梯度浓度KOH为淋洗液,淋洗液经捕获柱、抑制器成水后将样品带入质谱检测器。ESI-SIM监测模式监控柠檬酸根离子(m/z=191),并以峰面积进行定量。结果该方法对柠檬酸的检出限(S/N=3)为17.6μg/L,且柠檬酸浓度在50~1000μg/L范围内具有良好的线性,线性相关系数r=0.9992。200μg/L标准溶液重复进样8次,柠檬酸峰面积的相对标准偏差即精密度为0.77%。运用该方法测定市售5种不同品牌葡萄酒样品中柠檬酸的含量,并对样品加标回收,得回收率大于95%。结论该方法可以满足葡萄酒中柠檬酸定量分析的要求,且有效改善了分析的灵敏度和准确性。更多还原

【Abstract】 Objective To establish a rapid method for determination of citric acid in wine samples by ion chromatography-electrospray ionization tandem mass spectrometry(IC/ESI-MS) in the negative ESI and se- lected ion monitor(SIM) mode. Methods Citric acid was separated by high capacity and hydroxide selective column IonPac AS20 with KOH eluent generated from EGC. Peak area of citrate ion(m/z=191) was monitored for quantifying. Results The limit of detection was 17.6 μg/L for citric acid. A linear calibration was obtained over the range from 50 to 1000 μg/L with a correlation coefficient of 0.9992. The relative standard deviation for 8 injections of standard solution(200 μg/L) was 0.77%. This method was applied to detect the citric acid in different kinds of wine samples which were purchased in market, and the rates of recovery were higher than 95%. Conclusion The method could meet the requirements of quantitative analysis of citric acid in wine samples, and also could improve the sensitivity and accuracy of the analysis.更多还原