Evaluation of Quantitative Approaches in Non-Target LC/ESI/HRMS Analysis#

Authors#

Louise Malm, Jaanus Liigand, Reza Aalizadeh, Nikiforos Alygizakis, Kelsey Ng, Emil Egede Frøkjær, Mulatu Y. Nanusha, Martin Hansen, Merle Plassmann, Stefan Bieber, Thomas Letzel, Lydia Balest, Pier Paolo Abis, Michele Mazzetti, Barbara Kasprzyk-Hordern, Nicola Ceolotto, Sangeeta Kumari, Stephan Hann, Sven Kochmann, Teresa Steininger-Mairinger, Coralie Soulier, Giuseppe Mascolo, Sapia Murgolo, Manuel Garcia-Vara, Miren Lopez De Alda, Juliane Hollender, Katarzyna Arturi, Gianluca Coppola, Massimo Peruzzo, Hanna Joerss, Carla Van Der Neut-Marchand, Eelco N. Pieke, Pablo Gago-Ferrero, Ruben Gil-Solsona, Viktória Licul-Kucera, Claudio Roscioli, Sara Valsecchi, Austeja Luckute, Jan H. Christensen, Selina Tisler, Dennis Vughs, Nienke Meekel, Begoña Talavera Andújar, Dagny Aurich, Emma Schymanski, Gianfranco Frigerio, André Macherius, Uwe Kunkel, Tobias Bader, Pawel Rostkowski, Hans Gundersen, Belinda Valdecanas, W. Clay Davis, Bastian Schulze, Sarit Kaserzon, Martijn Pijnappels, Mar Esperanza, Aurelie Fildier, Emmanuelle Vulliet, Laure Wiest, Adrian Covaci, Alicia Macan Schönleben, Lidia Belova, Alberto Celma, Lubertus Bijlsma, Emilie Caupos, Emmanuelle Mebold, Julien Le Roux, Eugenie Troia, Eva De Rijke, Rick Helmus, Gaëla Leroy, Niels Haelewyck, David Chrastina, Milan Verwoert, Nikolaos S. Thomaidis, Anneli Kruve

Abstract#

Non-targeted screening (NTS) utilizing liquid chromatography electrospray ionization high-resolution mass spectrometry (LC/ESI/HRMS) is increasingly used to identify environmental contaminants. Major differences in the ionization efficiency of compounds in ESI/HRMS results in widely varying responses and complicates quantitative analysis. Despite an increasing number of methods for quantification without authentic standards in NTS, the approaches are evaluated on limited and diverse datasets with varying chemical coverage collected on different instruments, complicating an unbiased comparison. Here we evaluate five quantification approaches in an interlaboratory study organized by the NORMAN Network. Three approaches are based on surrogate standard quantification (parent-transformation product, structurally similar or close eluting) and two on predicted ionization efficiencies (RandFor-IE and MLR-IE). Shortly, HPLC grade water, tap water, and surface water spiked with 45 compounds at two concentration levels were analyzed together with 41 calibrants at six known concentrations by the laboratories using in-house NTS workflows. The accuracy of the approaches was evaluated by comparing the estimated and spiked concentrations across quantification approaches, instrumentation, and laboratories. The RandFor-IE approach performed best with reported mean prediction error of 15× and over 83% of compounds quantified within 10× error. Despite different instrumentation and workflows, the performance was stable across laboratories and did not depend on the complexity of water matrices.

Keywords: Liquid chromatography, Mass spectrometry, Semi-quantification, Interlaboratory study, Water samples, Ionization efficiency, Quantitative non-targeted analysis