title: Determination of piroxicam by solid-phase spectrophotometry in a continuous flow system.
abstract: A simple flow injection UV spectrophotometric method was developed for the determination of piroxicam. The method is based on its transient retention and concentration on Sephadex DEAE-A-25 anion-exchange gel beads packed in the flow cell and the continuous monitoring of its native absorbance on the solid phase at 354 nm. The sample was injected into a 0.1 M NaCl carrier stream at pH 9.5 by using a simple monochannel FIA manifold. When the analytical signal reached a maximum value, piroxicam was eluted from the solid support by means of a desorbing solution (0.2 M, pH 4.5). The response of the sensor was linear in the concentration range 0.5-10 microg ml(-1) with a R.S.D. (%) of 1.8, a detection limit (3 sigma criterion) of 0.1 microg ml(-1) and a sampling rate of 13 h(-1). Application to the analysis of pharmaceutical samples testifies to the utility of this sensor. The accuracy of the proposed method was better than 5%.
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, E-23071 Jaén, Spain. ipascual@ujaen.es
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Pascual-Reguera
authors.forename: María Jose
authors.initials: MJ
authors.lastname: Ayora-Cañada
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Castro Ruiz
mesh_terms: D000837:Anion Exchange Resins / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D002138:Calibration; D002626:Chemistry, Pharmaceutical; D004304:Dosage Forms; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D015394:Molecular Structure; D010894:Piroxicam / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation* / Q000379:methods*
chemical_list: D000837:Anion Exchange Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004304:Dosage Forms; D010894:Piroxicam