Determination of glyphosate and its derivative, aminomethylphosphonic acid, in human urine by gas chromatography coupled to tandem mass spectrometry and isotope pattern deconvolution

An analytical method for the simultaneous determination of glyphosate (GLY) and its main derivative, aminomethyl-phosphonic acid (AMPA), in human urine has been developed using gas chromatography coupled to tandem mass spectrometry (MS/MS) operated multiple reaction monitoring mode (MRM). Sample preparation involved dilution with water derivatization a mixture trifluoroacetic anhydride trifluoroethanol. Derivatization conditions such as time temperature, derivative stability, injection solvent, MS ionization MS-MS transitions, among others, were studied obtain highest sensitivity. The target compounds initially quantified by isotope isotopically labelled analogs GLY AMPA internal standards. However, due spectral overlap between selected quantitative transition, quantification based on pattern deconvolution (IPD) developed. instrumental limits detection 0.05 ng mL−1 both compounds, while 0.39 0.25 mL−1, GLY, respectively. mean recoveries from spiked at different concentrations 77 69% 90 102% respectively, relative standard deviations 8–10% (urine samples, n = 12) 3.6–4% (water 6). Once validated, feasibility was tested samples people living close agricultural areas. affords these trace complex matrices urine, avoiding elaborate handling cleanup steps. Isotope proven be successful alternative calibration curve overriding uncertainties associated overlapping.