摘要：Rapid and sensitive colorimetry of paraquat adsorbed on silica gel or florisil minicolumn (7 cm×1.2 mm) is described. The blood containing trace amounts of paraquat is deproteinized by the addition of a mixture of chloroform and methanol (3 : 2, v/v). After applying the supernatant to the silica gel minicolumn, the color reaction of paraquat is achieved by passing color-producing reagent (6% alkaline dithionite solution) through the minicolumn. A blue color due to paraquat radical (≨0.36 μg) is easily observed. After the adjustment of pH by the addition of activated alumina to pH=8.2-8.3, paraquat in the urine can be also detected by a similar method to silica gel minicolumn. For the semi-quantitative analysis of paraquat adsorbed on the minicolumn, paraquat is eluted with 1 N sodium hydroxide solution and the color-producing reagent is added to the eluate. Paraquat ion (0.72 μg in the blood 1 ml) can be easily determined by colorimetry. A similar method by using florisil minicolumn can be used for the qualitative analysis of paraquat in the blood and urine with pH above 13. These micromethods are suitable for the emergency detection of paraquat in the blood and urine of patients poisoned with paraquat.
关键词：paraquat;silica gel minicolumn;florisil minicolumn;paraquat adsorption;colorimetry;blood;urine
