Determination of paraquat in blood and urine by liquid chromatography-electrospray-

Paraquat (PQ) is a toxic quaternary ammonium compound widely used in agriculture. numerous cases of paraquat intoxication have been reported either accidentally or intentionally as suicidal attempts. A method for the determination of the herbicide PQ in blood and urine samples was developed using liquid chromatography-(electrospray ionization) mass spectrometry (LcesI-ms), following extraction with oasis® WcX solid-phase cartridges. chromatographic separation was achieved using an Atlantis® HILIc silica column, eluted isocratically with acetonitrile and ammonium formate (200mm) buffer, pH 3.8, at a 300 μL/min flow rate. Quantitation was achieved by the addition of ethyl paraquat as internal standard (Is). the compounds were detected monitoring two ions for PQ (m/z 185 and m/z 171) and m/z 213 for the Is. the method was applied to determine PQ in two cases: a non fatal case, a 42-year-old female with 0.13 μg/mL PQ concentration in blood and 6.29 μg/mL in urine and a lethal case, a 51-year-old male with 0.27 μg/ mL PQ concentration in blood. the authors developed a specific, sensitive and rapid assay for the identification and quantification of PQ, very important for monitoring suspected paraquat intoxications in hospitals and subsequently help in the treatment of these patients.