Laboratory of Analytical Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
Anal Chim Acta. 2013 Jan 25;761:217-26. doi: 10.1016/j.aca.2012.11.059. Epub 2012 Dec 10.
The applicability of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry to the screening of steroidal compounds in wastewater is demonstrated. Advanced software was utilized to identify unknown compounds in complex two-dimensional chromatograms exploiting retention indices and two different mass spectral databases. Response factors calculated as a function of the individual mass spectra of six commercial standards at different concentrations were used to develop a model allowing the quantitation of all steroidal compounds identified in the sample. The model, based on partial least squares regression equations, provided good accuracy (prediction error < 16%) in the quantitation of steroidal compounds, so offering a valuable alternative to conventional quantitation methods where reference compounds are required for the verification of analytical measurements. Special attention was paid to the development of an exhaustive sample preparation method for the separate analysis of conjugated and free steroids in both water phase and suspended solid particles. The method, including the exploitation of chemometrics, was successfully applied to the determination of steroidal compounds in effluent and influent waters collected at a local wastewater treatment plant.
本文展示了全二维气相色谱-飞行时间质谱在废水中甾体化合物筛选中的应用。利用保留指数和两个不同的质谱数据库，先进的软件被用于在复杂的二维色谱图中鉴定未知化合物。通过计算六种商业标准在不同浓度下的个体质谱的响应因子，建立了一个模型，允许对样品中鉴定出的所有甾体化合物进行定量。该模型基于偏最小二乘回归方程，在甾体化合物的定量中提供了良好的准确性（预测误差<16%），因此为需要参考化合物来验证分析测量的传统定量方法提供了有价值的替代方法。特别关注开发一种详尽的样品前处理方法，用于分别分析水相和悬浮固体颗粒中的共轭和游离甾体。该方法包括化学计量学的应用，成功地应用于当地污水处理厂的出水和进水水中甾体化合物的测定。
