HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF SPECTINOMYCIN IN SWINE, CALF AND CHICKEN PLASMA

A rapid clean-up procedure based on ion-pair solid-phase extraction (S PE) for the high-performance liquid chromatographic (HPLC) determinati on of spectinomycin in swine, calf and chicken plasma at a limit of de tection of 50 ng/ml is described. After dilution with water and adjust ment of the pH to approximately 5.6, the plasma is applied to a high-h ydrophobic C18 SPE column treated with sodium dioctylsulphosuccinate. Spectinomycin is eluted with methanol and derivatized with 2-naphthale ne sulphonyl chloride prior to chromatography. The HPLC set-up consist s of a dual-column system using two Chromspher silica columns and dich loromethane-acetonitrile-ethyl acetate-acetic acid, in different ratio s, as mobile phases. Detection is performed at 250 nm. Quantification is carried out using external standards prepared in blank cleaned plas ma. Mean recoveries were 83 +/- 3% (n = 5), 93 +/- 6% (n = 5) and 92 /- 6% (n = 6) for swine, calf and chicken plasma, respectively, at the 0.1 mug/ml level.