Amoxicillin is a member of a β-lactam antibiotic family. It is highly active against Gram- positive and Gram-negative organisms, including several pathogenic enteric organisms. Amoxicillin is often used in veterinary practice for gastro-intestinal therapy and systemic infections [1]. Chemiluminescence (CL) is the eliciting light from electronically excited species generated through an exothermic chemical reaction [2]. Determination of amoxicillin is very important in the quality control process during drug preparation in the pharmaceutical industry. In this study, after implementing some preliminary experiments, it found that amoxicillin showed inhibitory effect on the β-MnOOH nanoplates-enhanced H2O2-NaHCO3 CL system. Based on this finding, a sensitive and easy CL method was developed for the determination of amoxicillin in pharmaceutical formulations. Perhaps it is interesting to mention that among deferent CL systems such as peroxalate, lucigenin, 1,10-phenanthroline and luminol exploited as analytical detection system, the CL reaction of H2O2–NaHCO3 is one of the simplest and green CL systems involving non-toxic, easy available and inexpensive reagents [2]. After optimization, calibration graph of CL intensity versus amoxicillin concentration was plotted. The linear range of the calibration graph was 1.0 × 10-3 to 5.0 × 10- 5 mol L-1 with the correlation coefficient of the calibration line being r2 = 0.99. The limit of detection was equal to 4.9 × 10-5 mol L-1 and the relative standard deviation of the method with respect to 1.0 × 10-4 mol L-1 amoxicillin was equal to 2.4% (n = 4). In order to evaluate the selectivity of the CL method for amoxicillin, the effect of the presence of some foreign species, which might coexist with amoxicillin in real samples, on the CL signals recorded for the determination of 1.0 × 10-4 mol L-1amoxicillin was studied. The developed method was successfully applied to the determination of amoxicillin in pharmaceutical formulations. M
