Development of a slurry introduction method for multi-element analysis of antibiotics by inductively coupled plasma atomic emission spectrometry using various types of spray chamber and nebulizer configurations.

A direct sample introduction inductively coupled plasma atomic emission spectrometric (ICP-AES) method, for multi-element analysis of powdered antibiotic drugs was developed using the slurry formation technique. The slurry of powdered sample is formed in dilute nitric acid solution in presence of Triton X-100 surfactant. Two different configurations of spray chamber and nebulizer were tested for direct aspiration of slurry into the plasma: (i) cyclonic spray chamber combined with babington-type nebulizer and (ii) scott-type double-pass spray chamber combined with cross-flow nebulizer. The latter configuration proved to be less tolerable to slurry aspiration. RF power generator, nebulizer argon gas flow rate, nebulizer sample uptake flow rate and slurry sample concentration were optimized. The sensitivity of the proposed method was compared to the corresponding sensitivity obtained from aqueous solutions for each analyte. The performance characteristics of the slurry aspiration method were evaluated against the complete acid-digestion method followed ICP-AES. Finally, the proposed method was applied to the analysis of commercial antibiotics.