Liquid chromatographic determination of strychnine as poison in domestic animals

A liquid chromatographic (LC) method is described, using a preliminary thin layer chromatographic (TLC) screen followed by LC quantitation of strychnine in biological specimens of domestic animals. The TLC solvent system is also used as the LC mobile phase. Samples are extracted using acidic acetone, followed by evaporation of the acetone. The aqueous residue is extracted with ethyl ether, made basic with ammonium carbonate, and back-extracted into methylene chloride before TLC-LC analysis. The method has been successfully applied to liver, kidney, and urine specimens, as well as stomach contents. Six replicates each of a 0.75 and 7.5 ppm strychnine standard were taken through the method; recoveries ranged from 94 to 104%. Six replicates of a naturally incurred canine liver sample had a mean value of 3.9 ppm strychnine, with a standard deviation of 0.138 and a coefficient of variation of 3.58%.