Ascorbic acid (AA, vitamin C) and dehydroascorbic acid (DHA) constitute a biological couple. No technique can accurately, independently, and simultaneously quantify both members of the couple in animal and human samples, thereby constraining advances in physiology and pathophysiology. Here we describe a new UPLC/MS/MS method to measure both compounds directly and independently in human plasma. Lower limits of quantification were 16 nM, with linear coefficients >0.99 over a 100-fold concentration range. The method was stable and reproducible with <10 % injection-to-injection variation. Use of isotopic labeled internal standards for both compounds ensured precision and accuracy. Plasma preparation required only 2 steps. In plasma samples from 14 anonymized subjects who met criteria for blood donation, mean concentrations were 6±2 μmol/L (mean ± SD) and 56 ± 14 μmol/L for DHA and AA respectively, with (DHA)/(AA + DHA) ratio of 9.8 %. This method represents a pioneering approach to measuring the AA/DHA couple in human plasma.

中文翻译：

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人血浆中脱氢抗坏血酸的定量分析：通过 UPLC/MS-MS 同时直接测量抗坏血酸/脱氢抗坏血酸对


抗坏血酸（AA，维生素 C）和脱氢抗坏血酸 （DHA） 构成生物对。没有任何技术可以准确、独立和同时量化动物和人类样本中的这对夫妇，从而限制生理学和病理生理学的进步。本文介绍了一种新的 UPLC/MS/MS 方法，可直接独立地测量人血浆中的两种化合物。定量下限为 16 nM，在 100 倍浓度范围内线性系数为 >0.99。该方法稳定且可重现，进样间差异为 <10%。对两种化合物使用同位素标记的内标可确保精密度和准确度。血浆制备仅需 2 个步骤。在 14 名符合献血标准的匿名受试者的血浆样本中，DHA 和 AA 的平均浓度分别为 6±2 μmol/L（平均 ± SD）和 56 ± 14 μmol/L，（DHA）/（AA + DHA） 比率为 9.8 %。该方法代表了测量人血浆中 AA/DHA 对的开创性方法。