A new concept for isotope ratio monitoring liquid chromatography/mass spectrometry
A new concept for isotope ratio monitoring liquid chromatography/mass spectrometry
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DOI：
10.1002/rcm.1620
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发表时间：
2004-01-01
影响因子：
2
通讯作者：
Pesch, R
中科院分区：
文献类型：
--
作者：
Krummen, M;Hilkert, AW;Pesch, R
研制并测试了一种新的高效液相色谱仪与稳定同位素比质谱仪的在线联用接口。该接口可用于有机化合物的C-13/C-12测定，允许测量单个分析物物种中C-13丰度的微小变化。每个分析物中的所有碳都被定量地转化为二氧化碳，而分析物仍然溶解在水液相中。这是通过过氧二硫酸铵等氧化剂来实现的。二氧化碳从液体中分离出来，并转移到质谱仪。结果表明，整个集成过程没有引入同位素分馏。测得的碳同位素比值准确，重现性好。整个系统的灵敏度使同位素比率测定可以在柱上进行，最低可达400 ng化合物。绕过高效液相色谱(HPLC)分离，使得批量同位素分析的样本量大大低于传统元素分析仪所需的样本量。首次应用于氨基酸、碳水化合物和药物，从不同类型的高效液相色谱柱洗脱，提出了结果。广泛的色谱方法使化合物的分析前所未有地服从于同位素比质谱学技术，并可能导致许多新的分析方法的发展。版权所有(C)2004 John Wiley Sons，Ltd.
A new interface for the on-line coupling of a liquid chromatograph to a stable isotope ratio mass spectrometer has been developed and tested. The interface is usable for C-13/C-12 determination of organic compounds, allowing measurement of small changes in C-13 abundance in individual analyte species. All of the carbon in each analyte is quantitatively converted into CO2 while the analyte is still dissolved in the aqueous liquid phase. This is accomplished by an oxidizing agent such as ammonium peroxodisulfate. The CO2 is separated from the liquid phase and transferred to the mass spectrometer. It is shown that the whole integrated process does not introduce isotope fractionation. The measured carbon isotope ratios are accurate and reproducible. The sensitivity of the complete system allows isotope ratio determination down to 400ng of compound on-column. Bypassing the high-performance liquid chromatography (HPLC) separation allows bulk isotopic analysis with substantially lower sample amounts than those required by conventional elemental analyzers. The results of the first applications to amino acids, carbohydrates, and drugs, eluted from various types of HPLC columns, are presented. The wide range of chromatographic methods enables the analysis of compounds never before amenable to isotope ratio mass spectrometry techniques and may lead to the development of many new assays. Copyright (C) 2004 John Wiley Sons, Ltd.