University of Natural Resources and Life Sciences, BOKU Vienna, Department of Chemistry, Division of Analytical Chemistry, Vienna, Austria.
Metallomics. 2011 Dec;3(12):1304-9. doi: 10.1039/c1mt00114k. Epub 2011 Sep 16.
Integrating elemental labeling in quantitative LC-ICP-MS based bio-analysis requires fundamental experiments concerning the stability of complexes during analysis. In a competitive approach complex stability of the chelating moieties 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraaceticacid (DOTA), 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA) and diethylenetriaminepentaacetic dianhydride (DTPA) in combination with 11 different lanthanides was investigated under typical chromatographic conditions. Measurements were carried out via LC-ICP-QMS using a novel mixed mode separation method. The influence of chromatographic separation, pH and temperature on complex stability constants was assessed regarding further applications of multiplexing in bio-analytical assays. The limit of detection (LOD) for LC-ICP-QMS was 0.03 nM for all investigated Tm complexes (0.15 fmol absolute). Quantification of the complexes was performed via external, flow injection based calibration. For all investigated complexes the stability was significantly decreased by the chromatographic conditions. Moreover, complexation by DOTA revealed two different signals suggesting the presence of a stable intermediate product. Ln(3+)-DOTA and Ln(3+)-NOTA complexes provided high stability at 5 °C and 37 °C over a time of 12 hours, whereas Ln(3+)-DTPA complexes showed significant degradation at 37 °C.
在基于 LC-ICP-MS 的定量生物分析中整合元素标记需要关于分析过程中配合物稳定性的基础实验。在竞争方法中，研究了螯合部分 1,4,7,10-四氮杂环十二烷-N,N',N'',N'''-四乙酸（DOTA）、1,4,7-三氮杂环壬烷-N,N',N''-三乙酸（NOTA）和二亚乙基三胺五乙酸二酐（DTPA）与 11 种不同镧系元素的配合物稳定性，在典型的色谱条件下进行。通过 LC-ICP-QMS 进行测量，使用新型混合模式分离方法。评估了色谱分离、pH 值和温度对配合物稳定常数的影响，以进一步应用于生物分析测定中的多重分析。对于所有研究的 Tm 配合物，LC-ICP-QMS 的检测限（LOD）为 0.03 nM（0.15 飞摩尔绝对）。通过外部、基于流动注射的校准进行了配合物的定量。对于所有研究的配合物，其稳定性都因色谱条件而显著降低。此外，DOTA 的络合作用显示出两个不同的信号，表明存在稳定的中间产物。Ln(3+)-DOTA 和 Ln(3+)-NOTA 配合物在 5°C 和 37°C 下 12 小时内提供高稳定性，而 Ln(3+)-DTPA 配合物在 37°C 下显示出明显的降解。
