Determination of citrinin and sterigmatocystin in human urine: a risk assessment of citrinin exposure in the Valencian population

Aim: Mycotoxins are toxic secondary metabolites produced by various fungal species, commonly found as contaminants in food products and biological matrices. Due to their potential adverse effects on human health, reliable analytical methods for their detection are essential. Methods: This study presents the development and validation of an analytical method based on ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of the emerging mycotoxins citrinin (CIT) and sterigmatocystin (STG) in human urine. Sample preparation was optimized, performed using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction technique, selected for its high recovery rates and reproducibility. Results: The method demonstrated satisfactory linearity, precision, and sensitivity, with limits of quantification of 2.5 pg/mL and 0.75 pg/mL for CIT and STG, respectively. Analysis of twenty urine samples revealed the presence of CIT in six samples at trace concentrations, while STG was not detected above the quantification limit. Conclusions: A preliminary risk assessment of CIT indicated that the detected levels do not pose a significant toxicological risk. The validated method shows great potential for application in human biomonitoring studies aimed at assessing exposure to mycotoxins.