Abstract
A simplified assay method based upon that of Queree et al. for determination of paraquat ion in the liver and hemolyzed blood by reverse phase ion-pair chromatography is described for application to plasma samples. In the sample purification step by ion-pair extraction, after the back extration of paraquat with 0.5M sulfuric acid, the pH was raised to the permissible level by adding a sodium acetate solution in order to avoid peak splitting. Paraquat and ethylviologen, used as an internal standard, are eluted within about 8 min. Paraquat can be quantified by the present method down to a level comparable to that by second-derivative spectroscopy and a good correlation of the results was obtained between the two techniques for the concentration range of 0.4 to 90μg/ml. The coefficient of variation was about 3% at a paraquat ion concentration of about 5μg/ml.
