Determination of glyphosate and glufosinate in human serum by monospin TiO extraction and liquid chromatography–tandem mass spectrometry

We developed and validated an assay for determination of glyphosate (GLYP) and glufosinate (GLUF) in human serum. Serum samples were extracted by using a MonoSpin® TiO column and analyzed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). MonoSpin® TiO tends to specifically bind to phosphate groups. The assay was linear over a concentration range of 1–250 μg/mL. The recoveries for the 2 compounds were 1.6%–2.3%. The intra- and inter-day variations were <15%. Precision and accuracy were 5.6%–12.7% and 97.0%–103.9%, respectively. The validated method was applied to quantify the GLYP and GLUF content in the serum of GLYP and GLUF-poisoned patients. In conclusion, the method was successfully applied for accurate determination of GLYP and GLUF in serum obtained from patients with GLYP and GLUF poisoning.