Guide to Semi-Quantitative Non-Targeted Screening Using LC/ESI/HRMS

Autor: Amina Souihi, Louise Malm, Anneli Kruve, Jaanus Liigand, Merle Plassmann, Emma Palm
Rok vydání: 2021
Předmět:
Zdroj: Molecules, Vol 26, Iss 3524, p 3524 (2021)
Molecules
ISSN: 1420-3049
DOI: 10.3390/molecules26123524
Popis: Non-targeted screening (NTS) with reversed phase liquid chromatography electrospray ionization high resolution mass spectrometry (LC/ESI/HRMS) is increasingly employed as an alternative to targeted analysis; however, it is not possible to quantify all compounds found in a sample with analytical standards. As an alternative, semi-quantification strategies are, or at least should be, used to estimate the concentrations of the unknown compounds before final decision making. All steps in the analytical chain, from sample preparation to ionization conditions and data processing can influence the signals obtained, and thus the estimated concentrations. Therefore, each step needs to be considered carefully. Generally, less is more when it comes to choosing sample preparation as well as chromatographic and ionization conditions in NTS. By combining the positive and negative ionization mode, the performance of NTS can be improved, since different compounds ionize better in one or the other mode. Furthermore, NTS gives opportunities for retrospective analysis. In this tutorial, strategies for semi-quantification are described, sources potentially decreasing the signals are identified and possibilities to improve NTS are discussed. Additionally, examples of retrospective analysis are presented. Finally, we present a checklist for carrying out semi-quantitative NTS.
Databáze: OpenAIRE
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