Development and validation of a generic nontarget method based on liquid chromatography – high resolution mass spectrometry analysis for the evaluation of different wastewater treatment options

Abstract

A comprehensive workflow for using nontarget approaches as process evaluation tools was implemented, including data acquisition based on a LC-HRMS (QTOF) system using direct injection and data post-processing for the peak recognition in "full scan" data. Both parts of the approach were not only developed and validated in a conventional way using the suspected analysis of a set of spiked known micropollutants but also the nontarget analysis of a wastewater treatment plant (WWTP) effluent itself was utilized to consider a more environmental relevant range of analytes. Hereby, special focus was laid on the minimization of false positive results (FPs) during the peak recognition. The optimized data post-processing procedure reduced the percentage of FPs from 42% to 10-15%. Furthermore, the choice of a suitable chromatography for biological treated wastewater systems was also discussed during the method development. The workflow paid also attention to differences in the performance levels of the LC-HRMS system by implementation of an adaption system for intensity variations comparing different measurements dates or different instruments. The application of this workflow on wastewater samples from a municipal WWTP revealed that more than 91% compounds were eliminated by the biological treatment step and that the received effluent contained 55% newly formed potential transformation products.

Transformation of diclofenac in hybrid biofilm–activated sludge processes

“…Further details of the chromatography and acquisition method can be found in Schlüsener et al. (2015) and Nürenberg et al. (2015).…”

Extended Targeted and Non-Targeted Strategies for the Analysis of Marine Toxins in Mussels and Oysters by (LC-HRMS)

“…While there are several studies in the literature regarding the characterization and validation of targeted methods for the analysis of marine toxins in different matrices, both in low and high resolution [ 11 , 15 , 16 , 18 , 22 , 23 , 24 , 25 ], there are no studies presenting an appropriate characterized strategy for the non-targeted approach in the field of marine toxins. Only a few papers, inspired from the metabolomics approaches dealing with the analysis of environmental samples (wastewaters), addressed this challenge [ 26 , 27 , 28 , 29 , 30 , 31 ].…”

“…The expression “method characterization” should be understood throughout the manuscript as the assessment of some performances of the method but is different from a method validation, which is a more extensive and complete process. The method developed relies on a workflow ( Figure 1 ) combining both targeted and non-targeted analysis composed of three approaches; (1) targeted screening similar to low resolution MS where reference standards are used to search for the compounds of interest; (2) suspect screening that consists of querying a database/library including an exhaustive list of suspect compounds for which reference standards might not be available; and, (3) non-targeted screening performed without a priori, thus, without reference standards or suspects to identify unexpected compounds [ 26 , 28 ]. First, suitable chromatographic conditions are chosen for the separation of the selected toxins with a broad range of polarities.…”

High-throughput evaluation of organic contaminant removal efficiency in a wastewater treatment plant using direct injection UHPLC-Orbitrap-MS/MS

“…Nürenberg et al also presented a generic non-target screening approach that can be employed to study the effects of wastewater treatment. 31 Compared to our study, the data processing workow in Nürenberg et al (2015) used the picked peaks instead of compounds to assess relationships and differences within a sample set. An advantage of their workow is the amount of time saved by not conducting compound annotation and conrmation.…”

“…† The samples were analyzed in triplicate and each sample was injected three times, as multiple injections have been proven useful in reducing false positive results and in partially correcting for false negatives generated during the peak picking step in the non-target analysis protocol. 30,31 2.5. HRMS data post-processing workow All HRMS data were processed using Compound Discoverer 2.1 (Thermo Scientic).…”