QuEChERS analytical approach for monitoring endocrine-disrupting chemicals in human urine

This study introduces an analytical method for the determination of endocrine-disrupting chemicals (EDCs) in human urine samples, employing QuEChERS as a clean-up step for the first time in this biological matrix. Sample preparation was rigorously optimized through the evaluation of sample and final dilution volumes, balancing the need to reduce matrix interference without sacrificing sensitivity. High-performance liquid chromatography coupled with a triple quadrupole-time-of-flight mass spectrometer (HPLC-QTOF) was employed, enabling the detection of 13 target analytes (five OPEs, five phthalates, and three parabens' metabolites). Chromatographic separation was achieved in 16 min, and mass spectrometry parameters were fine-tuned to maximize signal sensitivity. The method was validated by assessing parameters such as selectivity, linearity, precision, accuracy, and sensitivity. Linearity of response was demonstrated for all of the compounds (r² > 0.99), with method detection limits of 0.01-0.33 ng/mL and limits of quantification of 0.03-1.08 ng/mL. Accuracy ranged from 67 to 99% and inter- and intra-day precision were under 20%, for the majority of the analytes. The validated method was then applied to 39 human urine samples, confirming its reliability and practical utility for monitoring EDC exposure in urban populations. The highest concentrations were found in parabens, followed by phthalates and finally OPEs, with median values of 117, 43.5, and 25.4 ng/g of creatinine, respectively. The detection of all three EDC groups in 100% of the samples underscores the importance of this comprehensive analytical approach being capable of simultaneously assessing these contaminants in human biomonitoring studies.