Mori K, Kidawara M, Iseki M, Umegaki C, Kishi T
Faculty of Pharmaceutical Sciences, Kobe-Gakuin University, Japan.
Chem Pharm Bull (Tokyo). 1998 Sep;46(9):1474-6. doi: 10.1248/cpb.46.1474.
A simple and accurate method for determination of vitamin C (ascorbic acid (AsA) and dehydroascorbic acid (DHA)) using 4,5-dimethyl-o-phenylenediamine (DMPD) was investigated. It was found that DMPD is a useful fluorescent reagent. The reaction product of DMPD with DHA showed strong and stable fluorescence (Ex; 360 nm, Em; 440 nm). Fluorometric derivatives were extracted with isobutanol or n-butanol. Extraction with isobutanol was superior to that with n-butanol in terms of specificity, since fluorometric derivatives of keto acids were extracted with n-butanol, together with DHA. The fluorescence intensity of DMPD derivatives was absolutely stable in isobutanol for at least 24 h. The sensitivity of determination of vitamin C was improved by removing several non-fluorometric compounds coexisting in the samples. The derivative derived from AsA was easily separated from those of keto acids by an HPLC method. The determination of vitamin C in natural products was thus improved by extraction and the HPLC method.
研究了一种使用4,5-二甲基邻苯二胺（DMPD）测定维生素C（抗坏血酸（AsA）和脱氢抗坏血酸（DHA））的简单准确方法。发现DMPD是一种有用的荧光试剂。DMPD与DHA的反应产物显示出强烈且稳定的荧光（激发波长；360nm，发射波长；440nm）。荧光衍生物用异丁醇或正丁醇萃取。就特异性而言，用异丁醇萃取优于用正丁醇萃取，因为酮酸的荧光衍生物与DHA一起被正丁醇萃取。DMPD衍生物的荧光强度在异丁醇中至少24小时绝对稳定。通过去除样品中共存的几种非荧光化合物提高了维生素C测定的灵敏度。通过HPLC方法，AsA衍生的衍生物很容易与酮酸的衍生物分离。因此，通过萃取和HPLC方法改进了天然产物中维生素C的测定。
