DETERMINATION OF ERYTHROMYCIN IN URINE AND PLASMA USING MICROBORE LIQUID-CHROMATOGRAPHY WITH TRIS(2,2'-BIPYRIDYL)RUTHENIUM(II) ELECTROGENERATED CHEMILUMINESCENCE DETECTION

Erythromycin is determined in both urine and plasma samples using micr obore reversed-phase liquid chromatography with tris(2,2'-bipyridyl)ru thenium(II) [Ru(bpy)(3)(2+)] electrogenerated chemiluminescence (ECL) detection. Ru(bpy)(3)(2+) is included in the mobile phase thus elimina ting band broadening caused by post-column reagent addition. Extra col umn band broadening is an important concern in microbore liquid chroma tography due to the small peak volumes. Erythromycin was studied in bo th water and biological samples. The detection limit for erythromycin in standards is 0.01 mu M or 50 fmol injected with a S/N of 3 and a li near working range that extends four orders of magnitude. Human urine and blood plasma were also studied. Urine samples were diluted and fil tered before injection. Ultrafiltration was used to remove protein fro m blood plasma samples prior to injection. Erythromycin was selectivel y detected in the body fluid samples without any further sample prepar ation, The detection limits obtained for erythromycin in urine and pla sma are 0.05 and 0.1 mu M, respectively, for 5 mu l injected on a 150X 1 mm I.D. C-18 column. (C) 1997 Elsevier Science B.V.