Analysis of glyphosate, aminomethylphosphonic acid, and glufosinate from human urine by HRAM LC-MS

• Published in: Analytical and bioanalytical chemistry Vol. 412; no. 30; pp. 8313 - 8324
• Main Authors: Franke, Adrian A., Li, Xingnan, Lai, Jennifer F.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2020; Springer; Springer Nature B.V
• Subjects: Accuracy; Acetic acid; Aminobutyrates - urine; Analysis; Analytical Chemistry; Antibiotics; Biochemistry; Characterization and Evaluation of Materials; Chemical properties; chemical species; Chemistry; Chemistry and Materials Science; Chlorides; Chromatography, Liquid - methods; Cross-sectional studies; derivatization; detection limit; Detergents; Edetic acid; EDTA (chelating agent); Ethylenediaminetetraacetic acids; Food Science; Glufosinate; Glycine - analogs & derivatives; Glycine - urine; Glyphosate; Health risks; Herbicides; Herbicides - urine; Human wastes; Humans; Laboratory Medicine; Limit of Detection; Liquid chromatography; Mass spectrometry; Mass Spectrometry - methods; Mass spectroscopy; Metabolites; Methods; Monitoring methods; Monitoring/Environmental Analysis; Organic acids; Organophosphonates - urine; Phosphonic acids; Pretreatment; Reproducibility of Results; Research Paper; Sensitivity analysis; solid phase extraction; Solid Phase Extraction - methods; Solid phases; Urine; United States; Urine; LC-MS; Aminomethylphosphonic acid; Glyphosate; Humans; Glufosinate
• ISSN: 1618-2642; 1618-2650; 1618-2650
• DOI: 10.1007/s00216-020-02966-1

Aminomethylphosphonic acid (AMPA) is the main metabolite of glyphosate (GLYP) and phosphonic acids in detergents. GLYP is a synthetic herbicide frequently used worldwide alone or together with its analog glufosinate (GLUF). The general public can be exposed to these potentially harmful chemicals; thus, sensitive methods to monitor them in humans are urgently required to evaluate health risks. We attempted to simultaneously detect GLYP, AMPA, and GLUF in human urine by high-resolution accurate-mass liquid chromatography mass spectrometry (HRAM LC-MS) before and after derivatization with 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) or 1-methylimidazole-sulfonyl chloride (ImS-Cl) with several urine pre-treatment and solid phase extraction (SPE) steps. Fmoc-Cl derivatization achieved the best combination of method sensitivity (limit of detection; LOD) and accuracy for all compounds compared to underivatized urine or ImS-Cl-derivatized urine. Before derivatization, the best steps for GLYP involved 0.4 mM ethylenediaminetetraacetic acid (EDTA) pre-treatment followed by SPE pre-cleanup (LOD 37 pg/mL), for AMPA involved no EDTA pre-treatment and no SPE pre-cleanup (LOD 20 pg/mL) or 0.2–0.4 mM EDTA pre-treatment with no SPE pre-cleanup (LOD 19–21 pg/mL), and for GLUF involved 0.4 mM EDTA pre-treatment and no SPE pre-cleanup (LOD 7 pg/mL). However, for these methods, accuracy was sufficient only for AMPA (101–105%), while being modest for GLYP (61%) and GLUF (63%). Different EDTA and SPE treatments prior to Fmoc-Cl derivatization resulted in high sensitivity for all analytes but satisfactory accuracy only for AMPA. Thus, we conclude that our HRAM LC-MS method is suited for urinary AMPA analysis in cross-sectional studies.