Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway.
J Chromatogr A. 2013 Jun 28;1296:196-203. doi: 10.1016/j.chroma.2013.03.072. Epub 2013 Apr 9.
Gas chromatography (GC) and liquid chromatography (LC) coupled to mass spectrometric (MS) detection have become the two main techniques for the analysis of metabolite pools (i.e. Metabolomics). These technologies are especially suited for Metabolite Profiling analysis of various metabolite groups due to high separation capabilities of the chromatographs and high sensitivity of the mass analysers. The trend in quantitative Metabolite Profiling is to add more metabolites and metabolite groups in a single method. This should not be done by compromising the analytical precision. Mass spectrometric detection comes with certain limitations, especially in the quantitative aspects as standards are needed for conversion of ion abundance to concentration and ionization efficiencies are directly dependent on eluent conditions. This calls for novel strategies to counteract all variables that can influence the quantitative precision. Usually, internal standards are used to correct any technical variation. For quantitation of single or just a few analytes this can be executed with spiking isotopically labeled standards. However, for more comprehensive analytical tasks, e.g. profiling tens or hundreds of analytes simultaneously, this strategy becomes expensive and in many cases isotopically labeled standards are not available. An alternative is to introduce a derivatizing step where the sample is derivatized with naturally labeled reagent, while a standard solution is separately derivatized with isotopically labeled reagent and spiked into the sample solution prior to analysis. This strategy, named isotope coded derivatization - ICD, is attractive in the emerging field of quantitative Metabolite Profiling where current protocols can easily comprise over hundred metabolites. This review provides an overview of isotopically labeled derivatizing reagents that have been developed for important metabolite groups with the aim to improve analytical performance and precision.
气相色谱（GC）和液相色谱（LC）与质谱（MS）检测相结合已成为分析代谢物池（即代谢组学）的两种主要技术。由于色谱仪具有高分离能力和质谱仪具有高灵敏度，这些技术特别适合于各种代谢物组的代谢物特征分析。定量代谢物特征分析的趋势是在单个方法中添加更多的代谢物和代谢物组。这不应以牺牲分析精度为代价。质谱检测存在一定的局限性，特别是在定量方面，因为需要标准品将离子丰度转换为浓度，并且离化效率直接取决于洗脱液条件。这需要新的策略来抵消所有可能影响定量精度的变量。通常，使用内标物来校正任何技术变化。对于单个或少数分析物的定量，可以通过添加同位素标记的标准品进行。然而，对于更全面的分析任务，例如同时分析数十或数百个分析物，这种策略变得昂贵，并且在许多情况下，同位素标记的标准品不可用。另一种方法是引入衍生化步骤，其中样品用天然标记的试剂衍生化，而标准溶液则用同位素标记的试剂单独衍生化，并在分析前加入到样品溶液中。这种策略称为同位素编码衍生化 - ICD，在新兴的定量代谢物特征分析领域很有吸引力，其中当前的方案很容易包含超过一百种代谢物。本文综述了为重要代谢物组开发的同位素标记衍生化试剂，旨在提高分析性能和精度。
