Avaliação de glifosato e ácido aminometilfosfônico (AMPA) Em urina de gestantes e puérperas na cidade do Rio de Janeiro por cromatografia líquida de alta eficiência acoplada a detector de fluorescência (CLAE-FLD)

Abstract

Glyphosate is a pesticide widely used in Brazil and worldwide, whose presence in environmental and biological matrices has raised scientific interest, particularly in the context of human biomonitoring studies. In this regard, the present study aimed to develop, optimize, validate, and apply an analytical method for the determination of glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), in urine samples from pregnant women. The method is based on high-performance liquid chromatography coupled with a fluorescence detector (HPLC-FLD), following derivatization with 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl). Sample preparation involved liquid–liquid extraction clean-up, derivatization, and solid-phase extraction steps, which were systematically optimized in terms of solvents, volumes, reaction time, and temperature. Method validation was carried out in accordance with national and international guidelines, including the Brazilian National Institute of Metrology, Quality and Technology (INMETRO), evaluating selectivity, linearity, limits of detection and quantification, precision, accuracy, repeatability, and intermediate precision. The method showed linear behavior over the concentration range of 0.5–10 μg L⁻¹ for both analytes, no significant matrix effect, and limits of detection of 0.03 μg L⁻¹ for glyphosate and 0.15 μg L⁻¹ for AMPA, with limits of quantification of 0.11 μg L⁻¹ and 0.50 μg L⁻¹, respectively. Recovery assays performed at different concentration levels within the established linear range yielded recoveries between 107–109% for glyphosate and 97–100% for AMPA, with low relative standard deviation values. After validation, the method was applied to the analysis of 10 urine samples from pregnant women residing in the state of Rio de Janeiro, Brazil. Glyphosate and AMPA concentrations in all analyzed samples were below the method detection limits. The analytical performance in real matrix was confirmed by fortified control samples at 2.5 μg L⁻¹, which demonstrated the robustness and reliability of the method. These results indicate that the developed method is suitable for the determination of glyphosate and AMPA in urine and presents strong potential for application in human biomonitoring studies.