HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF CLINDAMYCIN ANTIBIOTICS USING TRIS(BIPYRIDINE)-RUTHENIUM(III) CHEMILUMINESCENCE DETECTION

Postcolumn derivatization using the chemiluminescent reagent tris(2,2'-bipyridine)ruthenium(III) [Ru(bpy)33+] is applied to the detection of pharmaceuticals containing aliphatic tertiary amines. A detector designed to provide efficient mixing of the analyte and reagent with minimal extracolumn band broadening is characterized. The temperature of the Ru(bpy)33+ reagent is controlled at 0-2°C to increase stability. Also, flow rate profiles of both the reagent and carrier streams and the effect of an organic modifier on response are investigated. The optimized detector was used in the determination of the antibiotics clindamycin-2-phosphate and clindamycin in pharmaceutical samples. Detection limits are 10 ppb and 100 ppb for clindamycin-2-phosphate and clindamycin, respectively. This represents improvement by factors of about 100 and 30 over UV detection at 214 nm. The linear range covered 4 orders of magnitude.; Postcolumn derivatization using the chemiluminescent reagent tris(2,2′-bipyridine)ruthenium(III) [Ru(bpy)33+] is applied to the detection of pharmaceuticals containing aliphatic tertiary amines. A detector designed to provide efficient mixing of the analyte and reagent with minimal extracolumn band broadening is characterized. The temperature of the Ru(bpy)33+ reagent is controlled at 0-2°C to increase stability. Also, flow rate profiles of both the reagent and carrier streams and the effect of an organic modifier on response are investigated. The optimized detector was used in determination of the antibiotics clidamycin-2-phosphate and clindamycin in pharmaceutical samples. Detection limits are 10 ppb and 100 ppb for clidamycin-2-phosphate and clindamycin, respectively. This represents improvement by factors of about 100 and 30 over UV detection at 214 nm. The linear range covered 4 orders of magnitude.