采用离子排斥分离,电导检测模式,对威力酸中的4种有机酸成份进行分离测定。将威力酸样品通过萃取、洗涤、过滤之后进样,可以测定其柠檬酸、乳酸、苹果酸、富马酸4种有机酸,在一定的色谱条件下,4种阴离子都具有很好的线性和较低的检出限。威力酸中的柠檬酸,乳酸,苹果酸,富马酸的检出限分别是0.10、0.14、0.30和0.12μg/L,线性相关系数r^2在0.9997~0.9999范围内,样品中待测离子峰面积的RSD在4.3%以下(n=10),回收率在94%~105%之间。采用抑制电导的离子色谱法是分析威力酸中的有机酸成份的高效与准确的方法。
In this paper, a method for the simultaneous determination of four kinds of organic acids in Wei Li acid is proposed. The organic acids including citric acid, lactic acid, malic acid and fumaric acid were ananlyzed by means of ion chromatography using a gradient elution with heptafluorobutyric acid as mobile phase, Ion Pac ICE-AS6 as the separation column and suppressed conductivity detection. Optimized analytical conditions were further validated in terms of accuracy, precision and total uncertainty. The results showed the reliability of the IC method. Under favorable chromatographic conditions, good linear relationship, sensitivity and reproducibility were obtained. Detection limits of citric acid, lactic acid, malic acid and fumaric acid were 0.10, 0.14, 0.30 and 0.12 μg/L, respectively. Relative standard deviations of repeated analyses were less than 4.3% (n = 10). Recoveries were 94% - 105%.