Determination of Pyridine as a Decomposition Product in Ceftazidime and Mouthwash Solution

Abstract

In the practical procedure, 5 mu L of dimethyl sulfoxide (extraction/collection solvent) containing 1-pentanol (internal standard) is placed into a liner-shaped extraction vessel. The vessel is passed through the septum of a vial containing the sample solution. Then it is placed into a water bath thermostated at 70 degrees C. After a predetermined time, 1 mu L of the extraction/ collection solvent is removed and injected into the separation system. The factors influencing the extraction efficiency including extraction/collection solvent kind and its volume, ionic strength, extraction time, extraction temperature, and pH were investigated and optimized. Under optimum extraction conditions, the method showed a wide linear range between 0.012 and 500 mg L-1. Enrichment factor and extraction recovery were obtained as 314 and 94%, respectively. Limit of detection was calculated as 0.004 mg L-1 in solution and 0.08 mg kg(-1) in solid. Relative standard deviation for the extraction of 0.05 mg L-1 of the analyte was obtained as 4 and 6% for intra-day (n = 6) and inter-day (n = 4) precisions, respectively. Finally, the target analyte was determined in ceftazidime and mouthwash solution by the proposed method. In this study, a dynamic headspace liquid-phase microextraction method is reported for the extraction and preconcentration of pyridine as a decomposition product in some pharmaceuticals before its determination by gas chromatography-flame ionization detection.