High-throughput identification and determination of antifungal triazoles in human plasma using UPLC-QDa

Triazoles are common agents for invasive fungal infections, while therapeutic drug monitoring is needed to improve antifungal efficacy and reduce toxicity. This study aimed to exploit a simple and reliable liquid chromatography-mass spectrometry method for high-throughput monitoring of antifungal triazoles in human plasma using UPLC-QDa. Triazoles in plasma were separated by chromatography on a Waters BEH C18 column and detected using positive ions electrospray ionization fitted with single ion recording. M⁺ for fluconazole (m/z 307.11) and voriconazole (m/z 350.12), M²⁺ for posaconazole (m/z 351.17), itraconazole (m/z 353.13) and ketoconazole (m/z 266.08, IS) were selected as representative ions in single ion recording mode. The standard curves in plasma showed acceptable linearities over 1.25-40 μg/mL for fluconazole, 0.47-15 μg/mL for posaconazole and 0.39-12.5 μg/mL for voriconazole and itraconazole. The selectivity, specificity, accuracy, precision, recovery, matrix effect, and stability met acceptable practice standards under Food and Drug Administration method validation guidelines. This method was successfully applied to the therapeutic monitoring of triazoles in patients with invasive fungal infections, thereby guiding clinical medication.