Determination of gentian violet in animal feed, human urine, and wastewater by high pressure liquid chromatography.

Sensitive and specific procedures are described for the analysis of residues of gentian violet in animal feed, human urine, and wastewater at levels of 1000 ppm down to 10 ppb, 1 ppb, and 10 ppb, respectively. The cleaned-up extracts were analyzed by reverse-phase high pressure liquid chromatography by using an absorption detector at 588 nm. Recoveries of the compound from animal feed, human urine, and wastewater at the 10 ppb level were 79%, 58%, and 60%, respectively. Information concerning the stability of the compound in animal feed and the efficiency of extracting the residues is presented. Ancillary information is also reported concerning the separation and analysis of six related triphenylmethane dyes.