RESUMEN
Biomarker-driven research has been proposed as a successful method to assess the exposure of individuals to xenobiotics, including mycotoxins, through estimation of their metabolites in biological fluids. A methodology to determine patulin (PAT) and citrinin (CIT) in human urine and plasma using liquid chromatography coupled to tandem mass spectrometry was developed and validated in the present study. Selectivity/specificity, linearity, limit of detection and quantification, apparent recovery, intraday- and interday-precision and measurement uncertainty were investigated for validation purposes. Finally, the method was used to analyze human urine (n = 100) and plasma (n = 100) case-control samples, where 50 samples originated from colorectal cancer patients and 50 from age/sex-matched controls. This case-control study revealed that PAT was not detected in urine samples, however occurred in 25% of the analysed plasma samples with an average concentration of 11.62 ± 6.67 ng/mL in the positive samples. CIT was found in urine samples (74%) and plasma samples (36%) with average concentrations in the positive samples of 0.45 ± 0.24 ng/mL and 0.49 ± 0.2 ng/mL respectively. No statistically significant difference of PAT and CIT concentration among colorectal cancer and control patients (p > 0.05) was observed.