Abstract

A simple and effective one-step pre-column derivatization method for reversed-phase HPLC-UV determination of the major organic acids (citric, malic, tartaric, and succinic acids) in fruit juices has been developed. The method is based on the coupling reaction of organic acids with 1-naphthylamine in the presence of N,N′-diisopropylcarbodiimide. The resulting organic acid amide derivatives were successfully separated on an AQ-C18 column and detected by a UV detector at 222 nm. Isocratic elution was performed using an acetonitrile-methanol-tetrahydrofuran-water (37:4:1:58; v/v) mixture as a mobile phase at a flow rate of 2.0 mL/min. Validation studies showed good recoveries ranging from 88.97 to 92.52% with RSD % between 2.95 and 4.56%. The detection limits obtained were 0.18, 0.48, 0.14, and 0.69 µg/mL for tartaric acid, malic acid, succinic acid, and citric acid, respectively. The method was successfully applied to three different commercial fruit juice and nectar samples with little or no clean-up procedures.

摘要

开发了一种简单有效的一步柱前衍生方法，用于反相 HPLC-UV 测定果汁中的主要有机酸（柠檬酸、苹果酸、酒石酸和琥珀酸）。该方法基于有机酸与1-萘胺在N , N存在下的偶联反应'-二异丙基碳二亚胺。所得有机酰胺衍生物在AQ-C18柱上成功分离，并通过紫外检测器在222 nm处检测。使用乙腈-甲醇-四氢呋喃-水（37:4:1:58；v/v）混合物作为流动相，以2.0 mL/min的流速进行等度洗脱。验证研究显示回收率良好，范围为 88.97 至 92.52%，RSD % 为 2.95 至 4.56%。酒石酸、苹果酸、琥珀酸和柠檬酸的检测限分别为 0.18、0.48、0.14 和 0.69 µg/mL。该方法已成功应用于三种不同的商业果汁和花蜜样品，几乎不需要或不需要清理程序。