Spectrofluorometric Determination of Glyphosate in Water

Abstract

A sensitive, simple and selective spectrofluorometric method was developed for the trace level quantification of glyphosate from water. Due to lack of chromophore in glyphosate, the derivatization was accomplished using 9-fluoroenylmethoxycarbonyl chloride (FMOC-Cl). The derivatization conditions viz. pH of buffer, concentration of buffer, FMOC-Cl concentration etc. with respect to sensitivity of the analytical method were optimized. Under the optimized derivatization conditions, different concentrations of glyphosate ranging from 0.001-20 μg mL^–1 were quantified using fluorescence spectrophotometer, HPLC-UV and UV-visible spectrophotometer. In all cases coefficient of determination (R²) was 0.999. The minimum quantifiable limit using HPLC-UV, UV and fluorescence spectrophotometer were 0.03, 0.15, 0.003 μg mL^–1, indicating fluorescence spectrophotometer was the most sensitive technique. The percentage recoveries of glyphosate ranged from 95.2 ± 5.51 to 97.3 ± 6.07 with relative standard deviation (RSD) less than 6.3 %.