Ion-Pairing Flow Injection Analysis of Phenobarbiturate with Piezoelectric Detection

✍ Scribed by Zhihong Mo; Xiaohui Long; Yifeng Xu; Xudong Zhou

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 58 KB
• Volume: 62
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1999.1695

✦ Synopsis

New developments of ion-pairing flow injection with piezoelectric detection have been made for the analysis of the anionic drug phenobarbiturate. A cationic surfactant, hexadecyl trimethyl ammonium bromide, was used, and its adsorption and interfacial ion-pair formation with phenobarbiturate on the gold surface of piezoelectric quartz crystal were investigated. Modifications of the analytical system have been developed to improve its sensitivity, using reference and working detectors with higher frequencies, buffered reagent and sample solutions, and a short connecting tube. Influences of surfactant concentration and operating parameters were demonstrated. Under optimization for the determination of phenobarbiturate, the calibration curve was linear in the range 0 -1 mg ml Ϫ1 , with a detection limit of 0.44 g ml Ϫ1 , a recovery of 99.%, an RSD of 0.11% and a sampling frequency of 60 h Ϫ1 . The method has been satisfactorily applied to the determination of phenobarbiturate in pharmaceutical formulations.