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.