Simultaneous determination of glyphosate, glufosinate ammonium and their metabolites in maize and soybean by ultra-performance liquid chromatography with tandem mass spectrometry

Glyphosate and glufosinate ammonium are non-selective, broad spectrum herbicides for controlling grasses in agriculture and forestry. Rapid and sensitive analytical methods for effective monitoring and subsequent risk control of glyphosate and glufosinate ammonium and their metabolites in crops are not available. In this paper, an analytical method for the simultaneous determination of glyphosate, glufosinate ammonium, and their metabolites in maize and soybean by ultra-performance liquid chromatography with tandem mass spectrometry was established. The seven compounds were well separated on an anion exchange analytical column within 10 min, with the mean recoveries of the target compounds ranging from 78.2 to 110.9%. The method showed good linearity (R² ≥ 0.9819) with a limit of quantification for glyphosate, glufosinate ammonium, and their metabolites of 0.01 mg kg^-1 in both maize and soybean. The method simplifies and expedites the sample preparation procedures, overcomes the traditional disadvantages including derivatization, weak retention, and low sensitivity, and has been successfully validated in actual maize and soybean samples.