Determination of Amoxicillin with Novel Rhodanine Ramification by Flow Injection Chemiluminescence

3-(4´-fluorophenyl)-5-(2´-sulfonylphenylazo)-rhodanine (4FRASP) firstly synthesized by the authors was used as chemiluminescence (CL) reagent. In acidic medium, CL was observed when amoxicillin was injected into the mixture of 4FRASP-potassium permanganate. Based on this phenomenon, a flow injection CL method was established for the determination of amoxicillin. The CL intensity was correlated linear with the concentration of amoxicillin over the range of 5.0times10^-8 to 2.0times10^-5 g-mL^-1 and the detection limit was 4.5times10^-9 g-mL^-1. The relative standard deviation (RSD) was 1.3 % for determination of 1.0times10^-6 g-mL^-1 amoxicillin (n=11). This method was applied to the determination of amoxicillin in amoxicillin capsules successfully.