Using a simple high-performance liquid chromatography separation and fraction collection methodology to achieve compound-specific isotopic analysis for dissolved organic compounds.
Using a simple high-performance liquid chromatography separation and fraction collection methodology to achieve compound-specific isotopic analysis for dissolved organic compounds.
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使用简单的高效液相色谱分离和馏分收集方法来实现溶解有机化合物的化合物特异性同位素分析。
DOI：
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发表时间：
2005
影响因子：
2
通讯作者：
I. Clark
中科院分区：
文献类型：
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作者：
M. Marschner;P. Middlestead;I. Clark
开发了溶解无机和溶解有机碳化合物定量和同位素分析的新应用。天然水样中的溶解性有机物（DOM）可以在高效液相色谱（HPLC）柱上分离，并作为馏分收集。然后可以使用St-Jean（Rapid Commun.质谱仪二○ ○三年;十七日：419-428），其中总无机碳/总有机碳（TIC/TOC）分析仪与连续流同位素比质谱仪连接。使用短链脂肪酸标准品（甲酸、乙酸和丙酸）的实验数据表明，馏分回收率可能达到100%，并且保持了样品的完整性。在提取和收集之前和之后对产品进行的13 C-同位素分析显示，没有与方法相关的同位素效应，并且误差在IRMS的可接受分析不确定性范围内。纯标准品和富含有机物的天然沃茨的数据比较表明，定量分析仍然需要用更接近模拟样品基质的标准品进行，以获得适当的校准曲线。在HPLC柱上进样富含有机物的基质不影响馏分回收率，也不会产生从HPLC柱缓慢释放的部分保留有机化合物的高背景，因此13 C-同位素结果相对不受影响。该方法的具体限制是由于与TIC/TOC分析仪相关的潜在记忆效应而需要使用无碳载体溶剂。这一应用的进一步发展可以使更广泛的有机材料的常规化合物特异性同位素分析（CSIA）成为可能。
A new application for the quantitative and isotopic analyses of dissolved inorganic and dissolved organic carbon compounds has been developed. Dissolved organic matter (DOM) in natural water samples can be separated on a high-performance liquid chromatography (HPLC) column and collected as fractions. Each discrete fraction can then be analyzed using the technique of St-Jean (Rapid Commun. Mass Spectrom. 2003; 17: 419-428) with a total inorganic carbon/total organic carbon (TIC/TOC) analyzer interfaced with a continuous-flow isotope ratio mass spectrometer. Experimental data using short-chain fatty acid standards (formic, acetic, and propionic acids) show that fraction recoveries of 100% are possible and that sample integrity is maintained. 13C-isotopic analyses of products prior to and subsequent to extraction and collection show no isotopic effects associated with the methodology, and errors are well within the accepted analytical uncertainty of the IRMS. Comparison of data from pure standards and organic-rich natural waters shows that quantitative analyses still need to be done with standards that more closely imitate the matrices of the samples, in order to acquire an appropriate calibration curve. Injections of organic-rich matrices on the HPLC column did not affect fraction recovery, nor did they create high background of partially retained organic compounds slowly released from the HPLC column, and hence 13C-isotopic results are relatively unaffected. The specific limitation on this methodology is the required use of carbon-free carrier solvents due to potential memory effects associated with the TIC/TOC analyzer. Further developments of this application could make routine compound-specific isotopic analyses (CSIA) for a wider range of organic materials possible.