Comparative metabolite profiling of carboxylic acids in rat urine by CE-ESI MS/MS through positively pre-charged and 2H-coded derivatization
Comparative metabolite profiling of carboxylic acids in rat urine by CE-ESI MS/MS through positively pre-charged and 2H-coded derivatization
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DOI：
10.1002/elps.200800156
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发表时间：
2008-11-01
期刊：
影响因子：
2.9
通讯作者：
Adamec, Jiri
中科院分区：
文献类型：
--
作者：
Yang, Wen-Chu;Regnier, Fred E.;Adamec, Jiri
采用正电荷预充电和H-2编码衍生化的CE-MS方法，建立了一种新的大鼠尿液中羧酸类选择性比较代谢物谱分析方法。介绍了一种新型衍生化试剂--N-烷基-4-氨甲基吡啶碘化物（烷基=丁基、丁基-d9或己基），它含有季胺和稳定同位素原子（氘），可用于羧酸的衍生化。正极性CE分离显示出高重现性（迁移时间的0.99-1.32% RSD），消除了CE-MS阴离子分析中已知的毛细管涂层问题。衍生化后基本上完全的电离和增加的疏水性也增强了MS检测灵敏度（例如，在0.5 pg下检测到甲酸）。使用两种结构相似的试剂N-丁基-4-氨甲基-碘化吡啶（BAMP）和N-己基-4-氨甲基-碘化吡啶同时衍生一个样品，为识别未知样品中的羧酸提供了额外的信息。此外，通过在线CE-MS/MS获得的特征碎片允许对羧酸进行鉴定和分类。应用这种方法对大鼠尿液，我们发现59个离子匹配的特征模式的羧酸。在这59种离子中，有32种离子得到了阳性鉴定并用标准品进行了确认。为了进行比较分析，24种标准羧酸被化学上相同但同位素上不同的BAMP和N-丁基-d9-4-氨甲基-碘化吡啶衍生化，并测定其衍生化限度和线性范围。还对用BAMP和N-丁基-d9-4-氨甲基-碘化吡啶衍生的两个个体尿样进行了比较分析。这两份样品之间的代谢产物谱变化清晰可见。
A new approach to the selective comparative metabolite profiling of carboxylic acids in rat urine was established using CE-MS and a method for positively pre-charged and H-2-coded derivatization. Novel derivatizing reagents, N-alkyl-4-aminomethyl-pyridinum iodide (alkyl = butyl, butyl-d9 or hexyl), containing quaternary amine and stable-isotope atoms (deuterium), were introduced for the derivatization of carboxylic acids. CE separation in positive polarity showed high reproducibility (0.99-1.32% RSD of migration time) and eliminated problems with capillary coating known in CE-MS anion analyses. Essentially complete ionization and increased hydrophobicity after the derivatization also enhanced MS detection sensitivity (e.g. formic acid was detected at 0.5 pg). Simultaneous derivatization of one sample using two structurally similar reagents, N-butyl-4-aminomethyl-pyridinum iodide (BAMP) and N-hexyl-4-aminomethyl-pyridinum iodide, provided additional information for recognizing a carboxylic acid in an unknown sample. Moreover, characteristic fragmentation acquired by online CE-MS/MS allowed for identification and categorization of carboxylic acids. Applying this method on rat urine, we found 59 ions matching the characteristic patterns of carboxylic acids. From these 59, 32 ions were positively identified and confirmed with standards. For comparative analysis, 24 standard carboxylic acids were derivatized by chemically identical but isotopically distinct BAMP and N-butyl-d9-4-aminomethyl-pyridinium iodide, and their derivatization limits and linearity ranges were determined. Comparative analysis was also performed on two individual urine samples derivatized with BAMP and N-butyl-d9-4-aminomethyl-pyridinium iodide. The metabolite profiling variation between these two samples was clearly visualized.