Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, Spain.
J Chromatogr A. 2010 Jul 9;1217(28):4682-7. doi: 10.1016/j.chroma.2010.05.001.
This article reports a new procedure for the direct determination of faecal sterols coprostanol and cholesterol in wastewater samples as tracers of human sewage contamination. The method combines in-tube solid-phase microextraction (IT-SPME) for analyte enrichment and capillary liquid chromatography (LC) for separation with diode array detection for identification and quantification. A titania-based polymeric capillary column and a conventional octadecyl silica (ODS) capillary column were evaluated and compared for their ability to separate the analytes. The titania-based column allowed the separation of the analytes in much shorter chromatographic times and with better chromatographic profiles, which in turn resulted in better detectability. In addition, IT-SPME allowed the direct injection into the chromatographic system of sample volumes as large as 200 μL, thus making unnecessary off-line clean-up and concentration steps. In such a way, the tested compounds could be directly analysed in less than 10 min, the limits of detection (LODs) being 10 and 1.2 μg/L for coprostanol and cholesterol, respectively. The reliability of the proposed method was tested by processing several wastewater samples.
本文报道了一种新的方法，用于直接测定废水中粪便甾醇粪甾醇和胆固醇，作为人类污水污染的示踪物。该方法结合了管内固相微萃取（IT-SPME）进行分析物富集和毛细管液相色谱（LC）进行分离，二极管阵列检测用于鉴定和定量。评估并比较了基于 TiO2 的聚合物毛细管柱和常规十八烷基硅（ODS）毛细管柱分离分析物的能力。基于 TiO2 的柱允许在更短的色谱时间内分离分析物，并具有更好的色谱轮廓，从而提高了检测的灵敏度。此外，IT-SPME 允许直接将 200 μL 大体积的样品注入色谱系统，从而无需进行离线清洗和浓缩步骤。通过这种方式，测试化合物可以在不到 10 分钟的时间内直接分析，粪甾醇和胆固醇的检测限（LOD）分别为 10 和 1.2 μg/L。通过处理多个废水样品验证了所提出方法的可靠性。
