Deutsch J C, Kolhouse J F
Department of Medicine, Department of Veterans Affairs Hospital, Denver, Colorado.
Anal Chem. 1993 Feb 15;65(4):321-6. doi: 10.1021/ac00052a003.
The tert-butyldlmethylsllyl derivatives of ascorbic acid and dehydroascorbic acid were characterized by gas chromatography-mass spectrometry, and an isotope dilution assay for ascorbate and dehydroascorbate was developed using [13C6]ascorbic acid and [13C6]- and [6,6-2H2]dehydroascorbate. This assay was used to monitor ascorbic acid loss and the resulting rise of dehydroascorbic acid in aqueous solutions and plasma. Ascorbic acid was shown to rapidly decompose in aqueous solutions containing transition metal ions or when exposed to oxygen. Ethylenedlaminetetraacetic acid chelation did not prevent ascorbic acid degradation in aqueous solution, and ascorbate in ethylenedlaminetetraacetic acid chelated plasma was converted to dehydroascorbate on freezing. Gas chromatography-mass spectrometry appears to be a satisfactory method for determining the ascorbate and dehydroascorbate content of solutions including human blood plasma, whether or not there is ongoing oxidation of ascorbate in those solutions.
通过气相色谱 - 质谱联用对抗坏血酸和脱氢抗坏血酸的叔丁基二甲基硅烷基衍生物进行了表征，并使用[¹³C₆]抗坏血酸以及[¹³C₆]-和[6,6 - ²H₂]脱氢抗坏血酸开发了一种抗坏血酸盐和脱氢抗坏血酸盐的同位素稀释测定法。该测定法用于监测水溶液和血浆中抗坏血酸的损失以及由此导致的脱氢抗坏血酸的增加。结果表明，抗坏血酸在含有过渡金属离子的水溶液中或暴露于氧气时会迅速分解。乙二胺四乙酸螯合并不能防止抗坏血酸在水溶液中的降解，并且在冷冻时，乙二胺四乙酸螯合血浆中的抗坏血酸盐会转化为脱氢抗坏血酸盐。气相色谱 - 质谱联用似乎是一种用于测定包括人血浆在内的溶液中抗坏血酸盐和脱氢抗坏血酸盐含量的令人满意的方法，无论这些溶液中的抗坏血酸盐是否正在发生氧化。
