Yuuko S. Endoh

HPLC Determination of Sulfonamides, Their N4-Acetyl Metabolites and Diaminopyrimidine Coccidiostats in Chicken Tissues

Abstract A reversed-phase HPLC method is described for the quantitative determination of 5 sulfonamides, their N4-acetyl metabolites and 3 diaminopyrimidine coccidiostats in chicken muscle, liver, kidney, skin and plasma. Average recoveries from chicken tissues fortified with 0.05 and 0.2 μ/g of the 13 compounds were ranged from 53.9 to 106.3 % for individual compounds from individual tissues, with only 2 compounds from 1 tissue below 70 %. Coefficients of variation (C. V.) ranged from 0.6 to 21.3 %, with only 3 compounds from 1 tissue above 15 %. Detection limits were 0.0 2-0.0 5 μg/g for each compounds. The applicability of the method was demonstrated by determining concentrations of the 13 compounds in tissues from chickens administered with sulfonamides and diaminopyrimidines.

Simultaneous High-Performance Liquid Chromatographic Determination of Amprolium, Ethopabate, Sulfaquinoxaline and N4-Acetylsulfaquinoxaline in Chicken Tissues

Abstract A reversed-phase high-performance liquid chromatographic method is described for the quantitative simultaneous residue determination of amprolium with fluorometric detection using post-column reaction, and ethopabate, sulfaquinoxaline and its major metabolite, N4-acetylsulfaquinoxaline with UV detection, in chicken muscle, liver, kidney, skin and plasma. Average recoveries from chicken tissues fortified with 0.1 μg/g of the four compounds tested were ranged from 81.0 to 103.8 % for individual compounds from individual tissues. Coefficients of variation were ranged from 1.1 to 8.6 %. Detection limits were 0.002–0.004 μg/g for each compound. The applicability of this method was demonstrated by determining concentrations of the four compounds in tissues from chickens administered with the three parent compounds.

High-performance liquid chromatographic determination of pamaquine, primaquine and carboxy primaquine in calf plasma using electrochemical detection

A high-performance liquid chromatographic method with electrochemical detection is described for quantification of pamaquine, primaquine and carboxy primaquine in calf plasma. After the proteins had been precipitated with acetonitrile, the drugs were separated on a 5-microns C18-modified polymer gel column with an isocratic mobile phase. The detection limit was 0.01 microgram/ml in plasma for all three compounds. The applicability of the method in pharmacokinetic studies was demonstrated by determining the plasma concentrations of the three substances in calves administered a single dose of pamaquine or primaquine.