Gilker C D, Pesola G R, Matthews D E
Department of Medicine, Cornell University Medical College, New York, New York 10021.
Anal Biochem. 1992 Aug 15;205(1):172-8. doi: 10.1016/0003-2697(92)90595-x.
The stable isotope tracer [1,1,2,3,3,-2H5]glycerol has been commonly used as a tracer to measure glycerol kinetics and lipolysis in vivo. The method for measuring samples using the trimethylsilyl derivative and electron impact gas chromatograph-mass spectrometry retains only three of the five deuteriums, resulting in the possibility of incorrectly identifying the whole glycerol tracer molecule. This reports preparation of glycerol as the heptafluorobutyrl derivative and measurement by negative ion chemical ionization gas chromatography-mass spectrometry to produce a derivative with an intense molecular ion that retains all five deuterium labels. Thus the heptafluorobutyrl derivative analyzed by negative ion mass spectrometry overcomes the problems associated with fragmentation and loss of the isotopic label. Glycerol concentration using a labeled internal standard can be determined in plasma with a precision of 3%. Nanomole amounts of glycerol can be analyzed for 13C or 2H enrichments with a precision of +/- 0.14 mol% excess isotope. This simple, sensitive method for measuring glycerol levels and stable isotopic enrichment in plasma uses a simple extraction procedure and requires a minimal volume of plasma (less than 300 microliters).
稳定同位素示踪剂[1,1,2,3,3,-2H5]甘油已被广泛用作示踪剂，以测量体内甘油动力学和脂肪分解。使用三甲基硅烷基衍生物和电子轰击气相色谱-质谱法测量样品的方法仅保留了五个氘中的三个，从而有可能错误地识别整个甘油示踪剂分子。本报告介绍了甘油作为七氟丁酰基衍生物的制备方法，以及通过负离子化学电离气相色谱-质谱法进行测量，以产生具有强烈分子离子的衍生物，该衍生物保留了所有五个氘标记。因此，通过负离子质谱分析的七氟丁酰基衍生物克服了与同位素标记的碎片化和损失相关的问题。使用标记内标物可在血浆中测定甘油浓度，精密度为3%。可对纳摩尔量的甘油进行13C或2H富集分析，精密度为±0.14 mol%过量同位素。这种测量血浆中甘油水平和稳定同位素富集的简单、灵敏方法采用简单的提取程序，所需血浆体积最小（小于300微升）。
