Teruyo Yasui

Determination of Butylated Hydroxyanisole and Its Conjugated Metabolites in the Organs, Blood and Excreta of Mice by High-Performance Liquid Chromatography

The determination of butylated hydroxyanisole (BHA) and its conjugated metabolites (glucuronide and sulfate) in tissues and excreta of BHA administered mice was investigated by normal-phase high-performance liquid chromatography (HPLC). Male mice were orally administered BHA at 50 and 500 mg/kg, BHA and its metabolites were extracted from the liver and kidney by continuous extraction and from the blood, stomach, intestine, urine and feces by direct extraction. Conjugated metabolites were hydrolyzed with enzymes before extraction. BHA could be determined without influence from obstructive substances. In animals administered BHA at 500 mg/kg, unchanged BHA was present at high concentration in the liver, kidney and the blood 0.5 h later, but at 8 h could not be detected in any sample. The sulfate of BHA exceeded the glucuronide of BHA in the liver at 0.5 h, but the latter exceeded the former during 1 and 3 h after dosing. Mice excreted about 52% of 500 mg/kg during 8 h, and about 76% within 48 h in the urine as glucuronide (72.3±7.6%), sulfate (3.0±2.4%) and unchanged BHA (0.3±0.1%). However, about 25% of unchanged BHA was recovered from stomach at 8 h, and even after 48 h. some unchanged BHA could be found.