Determination of p-hydroxyphenoxymethylpenicillin in phenoxymethylpenicillin by derivative spectrophotometry
A spectrophotometric method has been developed for the determination of p-hydroxyphenoxymethylpenicillin in samples of phenoxymethylpenicillin via the fourth-derivative spectra. The data were compared with results obtained by HPLC. For p-hydroxypenicillin V and p-hydroxyphenoxyacetic acid the HPLC method is the more selective, but its reproducibility is lower than that of the derivative spectrophotometric method. The short analysis time and low costs are the main advantages of the latter method.