Application of Azure C for the extractive spectrophotometric determination of microgram amounts of penicillin.
A simple, accurate, and rapid method for the quantitative determination of penicillin is proposed. The method is based on the formation of a blue penicillin-Azure-C ion-pair that can be extracted into chloroform in phosphate-citric acid buffer. The molar absorptivities for sodium penicillin G and potassium penicillin V at 635 nm were 5.46 X 10(3) and 2.19 X 10(4) l/mol/cm, respectively. Beer's law was valid over the concentration range of 4-80 micrograms/ml for sodium penicillin G and 3-55 micrograms/ml for potassium penicillin v. Maximum absorbance was obtained almost instantaneously and was stable for several days. The method was successfully applied to pharmaceutical preparations.
D001399:Azure Stains; D002021:Buffers; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D010400:Penicillin G / Q000032:analysis; D010404:Penicillin V / Q000032:analysis; D010406:Penicillins / Q000032:analysis*; D010640:Phenothiazines; D013053:Spectrophotometry
D001399:Azure Stains; D002021:Buffers; D007202:Indicators and Reagents; D010406:Penicillins; D010640:Phenothiazines; C045363:Azure C; D010400:Penicillin G; D010404:Penicillin V