Liquid chromatography-high resolution mass spectrometry methods for the identification of antifungal azoles’ transformation products through suspect and non-target analysis

Abstract

Azoles, known for their antifungal properties, are among the most produced and utilized chemical classes globally, categorized into imidazole ring and triazole ring molecules bearing various substituents. They are recognized as a significant group of environmental contaminants. Owing to their widespread presence, persistence, and potential toxicity to humans and the environment, several azole compounds have been incorporated into the 4th European Union Watch List, which has been in place since 2022, continuing to include azolic fungicides similarly to previous editions. Azoles can undergo metabolism by microorganisms or various chemical degradation processes, resulting in transformation products (TPs) that may possess altered chemical properties, increased toxicity, and higher persistence and concentrations. Consequently, the identification and structural elucidation of azoles’ TPs are critical, with liquid chromatography high-resolution mass spectrometry (HRMS) playing a key role.

Recent advancements in non-target and suspect screening methods, alongside improvements in LC-HRMS technology, have greatly enhanced the field of environmental analytical chemistry. These innovations enable the detection and identification of both known and unknown compounds in samples without the need to fully depend on chemical standards. This review focuses on recent advancements in LC-HRMS techniques, especially those utilizing suspect and non-target screening for analyzing and elucidating the structure of azoles’ TPs. It discusses analytical methodologies, data processing workflows, and reviews studies on TPs found in environmental matrices, as well as those investigating advanced oxidation processes and biodegradation of azoles.