title: Quantification of benzocaine and its metabolites in channel catfish tissues and fluids by HPLC.
abstract: Methods for extraction and gradient HPLC quantification were developed for benzocaine (BZ) and three of its metabolites to be used in conjunction with a reverse isotope technique. The metabolites were p-aminobenzoic acid (PABA), acetyl-p-aminobenzoic acid (AcPABA) and acetylbenzocaine (AcBZ). The matrixes studied were white muscle, red muscle, skin, liver, trunk kidney, head kidney, plasma and the bile of channel catfish. Analytes were validated for each of the compounds at 25 and 100 nmol per sample in the various tissues and fluids. The intraday variability (R.S.D.) was less than 13% in all tissues and fluids except for BZ in the liver. Recoveries varied from matrix to matrix for each analyte. The highest recoveries were obtained from plasma which ranged from 82.8-99.8% depending on the concentration. The average recovery of the compounds from tissues was between 50 and 78%, except for liver where the recovery of PABA and BZ was below 30%. Detection was by UV absorbance at 286 nm and the linear range was 2.5-15 nmol 100 ml-1 for all analytes. The method was selective; no interference peaks coeluted with the analytes.
authors.affiliation: Ohio State University, College of Pharmacy, Columbus 43210, USA.
authors.forename: A
authors.initials: A
authors.lastname: Szoke
authors.forename: W L
authors.initials: WL
authors.lastname: Hayton
authors.forename: I R
authors.initials: IR
authors.lastname: Schultz
mesh_terms: D010129:4-Aminobenzoic Acid / Q000032:analysis* / Q000493:pharmacokinetics; D000818:Animals; D001566:Benzocaine / Q000032:analysis* / Q000378:metabolism / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D007059:Ictaluridae / Q000378:metabolism*; D015203:Reproducibility of Results; D014018:Tissue Distribution; D062366:para-Aminobenzoates
chemical_list: D062366:para-Aminobenzoates; C023730:Acedoben; D010129:4-Aminobenzoic Acid; D001566:Benzocaine