Panoramic Semiquantitave Analysis for Multielement Characterization of Liquid and Solid Waste Samples

Abstract

Wastewater treatment results in large amounts of sewage sludge in the wastewater treatment plant (WWTP) which imposes on its reuse. The most promising application is as a fertilizer in agriculture which is regulated by national and European legislation. Along with the mandatory determination of potentially toxic elements (PTEs), in order to assess not only the risks, but also the beneficial properties, the determination of the total chemical composition is desirable. Inductively coupled plasma mass spectrometry (ICP-MS) is the most promising technique for multielement characterization which can be applied both for quantitative and semiquantitative analysis. A significant difference between the approaches is that the semiquantitative analysis is performed after a calibration with one standard solution containing at least three elements, but, at the same time, the accuracy is worse. In the present work, the accuracy of semiquantitative analysis with a different number of calibration elements using both water standard solutions and certified reference material (CRM) for calibration was investigated for the determination of 69 elements in sewage sludge CRMs and samples. It has been found that the accuracy can vary within a wide range, depending on the concentration of the elements, the number of calibration elements, and/or the presence of neighboring masses. In order to obtain an accuracy of up to 30%, it is recommended to shorten the mass intervals and perform the calibration with at least 18 elements, mainly microelements. The method was applied for fast panoramic analysis of sewage sludge samples from WWTPs and the concentrations were close to the data from quantitative analysis.