Cullum M E, Olson J A, Veysey S W
Int J Vitam Nutr Res. 1984;54(1):3-10.
To evaluate the total body reserves of vitamin A in humans, deuterated forms of vitamin A are potentially useful probes. In the present investigation, we have selected anhydroretinol as a useful indicator of retinol isolated from plasma during GC/MS analysis because of its relatively high volatility, its formation from retinol in good yield directly on GC columns, and the improbability of deuterium loss or exchange during its formation. The major drawback in its use is the extensive isomerization to cis-isomers which occurred on GC columns even under mild conditions of analysis. Favorable conditions for the GC/MS assay of anhydroretinol in the EI mode were defined. The mass spectral response is linear with the amount of retinol injected from 10 to 400 ng, and the observed sensitivity is adequate for the measurement of retinol in 1 ml of plasma. By using isobutane or methane, chemical ionization mass spectra of anhydroretinol and retinaldehyde are reported for the first time. Although both gave the expected [M + H]+ molecular ion, analysis of anhydroretinol in the EI mode was a more appropriate and sensitive measure of retinol under our assay conditions.
为评估人体维生素A的全身储备情况，氘代形式的维生素A可能是有用的探针。在本研究中，我们选择脱水视黄醇作为在气相色谱/质谱分析期间从血浆中分离出的视黄醇的有用指标，这是因为它具有相对较高的挥发性、在气相色谱柱上能以较高产率直接由视黄醇形成，并且在其形成过程中氘丢失或交换的可能性较小。使用它的主要缺点是即使在温和的分析条件下，在气相色谱柱上也会广泛异构化为顺式异构体。确定了在电子轰击（EI）模式下对脱水视黄醇进行气相色谱/质谱分析的有利条件。质谱响应与注入的视黄醇量在10至400纳克范围内呈线性关系，观察到的灵敏度足以测量1毫升血浆中的视黄醇。首次报道了使用异丁烷或甲烷时脱水视黄醇和视黄醛的化学电离质谱。虽然两者都给出了预期的[M + H]+分子离子，但在我们的分析条件下，以EI模式分析脱水视黄醇对视黄醇来说是一种更合适且灵敏的测量方法。
