Université Aix-Marseille I-CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrométries Appliquées à la Chimie Structurale, Marseille, France.
J Am Soc Mass Spectrom. 2010 Jan;21(1):60-7. doi: 10.1016/j.jasms.2009.09.002. Epub 2009 Sep 12.
Quantitative isomeric analysis of fructose, galactose, and glucose was achieved using electrospray ionization and trimeric ion dissociation with data analysis by the kinetic method. Several L-amino acids and divalent metal cations were tested to select the best systems for isomeric distinction and quantitation of each monosaccharide. High discrimination could be achieved for most tested systems, and serine/Cu(2+) and aspartic acid/Mn(2+) were selected for quantitative analysis due to their ability to strongly distinguish the three analytes and to allow long-term reproducible measuring conditions. Accurate quantitative results were obtained for all isomers using three-point corrected calibration curves, which account for the competition effects evidenced to occur between sugars for the formation of the trimeric complexes. As a result, the relative proportion of one isomer in the liquid and in the gas phase depends on the sugar mixture composition. However, for a given reference/metal system, the extent of competition effects was shown to be constant within a given pair of sugars. The correction factors could thus be established based on data obtained from binary mixtures and successfully used for ternary sample analysis.
采用电喷雾电离和三聚体离子解离，并通过动力学方法进行数据分析，实现了果糖、半乳糖和葡萄糖的定量对映异构体分析。测试了几种 L-氨基酸和二价金属阳离子，以选择用于对映异构体区分和每种单糖定量的最佳系统。对于大多数测试系统都可以实现高的区分度，由于能够强烈区分三种分析物并允许长期可重复的测量条件，因此选择丝氨酸/Cu(2+)和天冬氨酸/Mn(2+)用于定量分析。使用三点校正校准曲线可获得所有异构体的准确定量结果，该曲线考虑了在形成三聚体配合物时糖之间存在的竞争效应。因此，一种异构体在液相和气相中的相对比例取决于糖混合物的组成。然而，对于给定的参考/金属系统，在给定的一对糖之间，竞争效应的程度被证明是恒定的。因此，可以基于从二元混合物获得的数据建立校正因子，并成功用于三元样品分析。
