High-performance liquid chromatographic determination of piperacillin in plasma

A high-performance liquid chromatographic method has been developed for the quantitative determination of piperacillin in plasma. The compound is first extracted from acid-treated plasma into chloroform: 1-pentanol (3:1) and reextracted into a small volume of an aqueous phase at pH 7, which is injected in the chromatographic column (microgram-Bondapack C18; 10 micrometers). The mobile phase is a mixture of 0.01 M acetate buffer (pH 4.8) and methanol. The method is accurate and reproducible with a sensitivity of about 50 ng of piperacillin per ml of serum.