OBJECTIVE: To establish a new method for the analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector. METHODS: An initial procedure of precipitation was performed by adding hydrochloric solution with sodium chloride and a mixture of chloroform and ethanol. Then the analyte contained in supernatant was reduced by a reduction system of sodium borohydride and nickel chloride and extracted by acetic ether. Ethyl paraquat (EPQ) was used as internal standard. GC/TSD was used to identify and quantify the analyte. RESULTS: The limits of detection (S/N=3) in blood and urine were 0.002 and 0.004 microg/mL, respectively. The linear ranges were 0.050-30.0 microg/mL. Correlation coefficients in blood and urine were 0.999 and 0.998, respectively. The recoveries exceeded 80% both in blood and urine. CONCLUSION This method is applicable for quantification of paraquat in biological fluids.
Borohydrides/chemistry* ; Chromatography, Gas/methods* ; Forensic Toxicology ; Herbicides/urine* ; Humans ; Nickel/chemistry* ; Oxidation-Reduction ; Paraquat/urine* ; Sensitivity and Specificity