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 (LCES
I-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