Automated Derivatization, SPE Cleanup and LC/MS/MS Determination of Glyphosate and Other Polar Pesticides

Glyphosate and glufosinate are widely used herbicides and, thus, there is an interest in the reliable and sensitive determination of glyphosate in water and food. These pesticides are diffi cult to extract and analyze because of their high polarity. In this report, we describe an automated workfl ow for the FMOC-derivatization, sample cleanup, and LC/MS/MS analysis using a GERSTEL MultiPurpose Sampler (MPS XL) confi gured with an online solid phase extraction (SPEXOS) module coupled to an AB SCIEX QTRAP® 4500 system for the identifi cation and quantitation of glyphosate, its major metabolite AMPA, and glufosinate in water and food samples. The online SPE-LC/MS/MS method allowed detection and quantitation of all target pesticides in matrix samples at 10 μg/kg concentration levels with excellent reproducibility and values well within the ± 20 % range.