A multi-residue chiral liquid chromatography coupled with tandem mass spectrometry method for analysis of antifungal agents and their metabolites in aqueous environmental matrices

Abstract

The presence and fate of antifungal agents in the environment have hardly been investigated. This is despite the increased usage of antifungal agents and higher prevalence of antifungal resistance. Stereochemistry of antifungal agents has been largely overlooked due to lack of analytical methods enabling studies at the enantiomeric level. This paper introduces a new analytical method for combined separation of achiral and chiral antifungal agents and their metabolites with the utilization of chiral chromatography coupled with triple quadrupole tandem mass spectrometry to enable comprehensive profiling of wide-ranging antifungal agents and their metabolites in environmental matrices. The method showed very good linearity and range (r² > 0.997), method accuracy (61–143%) and precision (3–31%) as well as low (ng L⁻¹) MQLs for most analytes. The method was applied in selected environmental samples. The following analytes were quantified: fluconazole, terbinafine, N-desmethyl-carboxyterbinafine, tebuconazole, epoxiconazole, propiconazole and N-deacetyl ketoconazole. They were predominantly present in the aqueous environment (as opposed to wastewater) with sources linked with animal and plant protection rather than usage in humans. Interestingly, chiral fungicides quantified in river water were enriched with one enantiomer. This might have consequences in terms of their ecological effects which warrants further study.