Mix-mode TiO-C18 Monolith Spin Column Extraction and GC-MS for the Simultaneous Assay of Organophosphorus Compounds and Glufosinate, and Glyphosate in Human Serum and Urine

A rapid, specific, and sensitive method for the simultaneous quantitation of organophosphates (fenitrothion (MEP), malathion, and phenthoate (PAP)), glufosinate (GLUF), and glyphosate (GLYP) in human serum and urine by gas chromatography-mass spectrometry (GC-MS) has been validated. All of the targeted compounds together with the internal standard were extracted from the serum and urine using a mix-mode TiO-C-18 monolithic spin column. The recovery of organophosphates from serum and urine ranged from 12.7 to 49.5%. The recovery of GLUF and GLYP from serum and urine ranged from 1.9 to 7.9%. The intra- and inter-accuracy and precision (expressed as relative standard deviation, %RSD) were within 96.7 - 107.7% and 4.0 - 13.8%, respectively. The detection and quantitation limits for serum and urine were 0.1 and 0.1 mu g/ml, respectively, for organophosphates, 0.1 and 0.5 mu g/ml, respectively for GLUF and GLYP. The method had linear calibration curves ranging from 0.1 to 25.0 mu g/ml for organophosphates and 0.5 - 100.0 mu g/ml for GLUF, and GLYP. The validated method was successfully applied to a clinical GLYP poisoning case.