title: Application of a continuous square-wave potential program for sub nano molar determination of ketotifen.
abstract: An electroanalytical method has been developed for the determination of the ketotifen by continuous square wave adsorptive stripping voltammetry on a ultra-gold microelectrode (Au UME) in aqueous solution with phosphate buffer as supporting electrolyte. The best adsorption conditions were found to be pH 2.3, an accumulation potential of 300 mV (Au vs. Ag: AgCl-KCl 3 M) and an accumulation time of 400 ms. Variation of admittance in the detection process is created by inhibition of oxidation reaction of the electrode surface, by adsorption of ketotifen. Furthermore, signal-to-noise ratio was significantly increased by application of discrete fast Fourier transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. Also in this work some parameters such as square-wave frequency, eluent pH, and accumulation time were optimized. Effects of square-wave frequency, step potential and pulse amplitude were examined for the optimization of instrumental conditions. The calibration curve is linear in the range 2.0x10(-7)---5.0x10(-12) M with a detection limit of 2.0x10(-12) M (ca. 0.7 pg/ml). The method maybe applied direct determination of the drug in pharmaceutical and biological samples. For a concentration of 5.0x10(-8) M a recovery value of 99.89% is obtained.
authors.affiliation: Department of Chemistry, University of Tehran, Iran.
authors.forename: Parandis
authors.initials: P
authors.lastname: Daneshgar
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
mesh_terms: D000465:Algorithms; D002021:Buffers; D002138:Calibration; D003627:Data Interpretation, Statistical; D004563:Electrochemistry / Q000295:instrumentation; D006634:Histamine H1 Antagonists / Q000032:analysis* / Q000097:blood / Q000652:urine; D006863:Hydrogen-Ion Concentration; D007665:Ketotifen / Q000032:analysis* / Q000097:blood / Q000652:urine; D008839:Microelectrodes; D036103:Nanotechnology; D012984:Software; D012996:Solutions
chemical_list: D002021:Buffers; D006634:Histamine H1 Antagonists; D012996:Solutions; D007665:Ketotifen