Sensitive, rapid and non-derivatized determination of glyphosate, glufosinate, bialaphos and metabolites in surface water by LC–MS/MS

Glyphosate, glufosinate and bialaphos are widely used worldwide as herbicides. It has been reported that they can transfer into environmental water bodies, posing health threat to human. Thus, a sensitive and rapid analysis methodology for these compounds and corresponding metabolites is highly necessary. Due to their zwitterionic nature, previously reported methods for determination of these compounds generally require derivatization. Also, preconcentration step is typically needed in order to obtain high sensitivity. Herein, we report a very convenient and sensitive assay for these herbicides as well as corresponding metabolites in surface water. With judicious tuning of chromatographic conditions, very low LODs were achieved without derivatization or preconcentration step. The LODs were 0.15 ng mL−1 for glyphosate, glufosinate, MPPA and bialaphos, 0.1 ng mL−1 for AMPA. The LOQs were 0.5 ng mL−1 for glyphosate, glufosinate, MPPA and bialaphos, 0.3 ng mL−1 for AMPA. Recoveries ranging in 90.3–102.8% were obtained. The intra-day relative standard deviations (RSDs) ranged in 4.0–5.6%, while the inter-day RSDs ranged in 4.7–6.7%. The ME (n = 6) ranged from 92.6 to 97.2%. This assay was applied to real samples of surface water. This method is very promising for application in determination and routine monitoring of these compounds in environmental water bodies.