A simple method for routine monitoring of glyphosate and its main metabolite in surface waters using lyophilization and LC-FLD+MS/MS. Case study: canals with influence on Biscayne National Park.

A novel method was developed for the analysis of the herbicide glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) based on lyophilization. Sample preparation steps are limited to fortification with aspartic acid as internal standard and water removal by lyophilization (3-4 days for 72 samples), followed by suspension of dry residues in borate buffer (pH=9.0) and addition of ethylenediaminetetraacetic acid (EDTA) and 9-fluorenylmethylchloroformate (FMOC-Cl) for pre-column derivatization.