Flow‐injection–chemiluminescence method for the determination of penicillin G potassium

The degradation product of penicillin G potassium can react with potassium permanganate in acidic medium and produce chemiluminescence, which is greatly enhanced by formaldehyde. The optimum conditions for this chemiluminescent reaction were studied in detail using a flow‐injection system. The experiments indicated that under optimum conditions, the chemiluminescence intensity was linearly related to the concentration of penicillin G potassium within the range 1.0 × 10 −7 –1.0 × 10 −5 g/mL, with a detection limit (3 σ ) of 7 × 10 −8 g/mL. The relative standard deviation was 1.0% for 4.0 × 10 −7 g/mL penicillin G potassium solution ( n = 11). This method has the advantages of simple operation, fast response and high sensitivity. The method was successfully applied to the analysis of penicillin G potassium in raw medicines. Copyright © 2005 John Wiley & Sons, Ltd.