title: Ultrasensitive flow-injection electrochemical method for detection of anticancer drug tamoxifen.
abstract: This paper presents the optimization of instrumental and solution parameters for determination of tamoxifen in urine and plasma and formulation by fast Fourier transform square wave voltammetry (SWV) using a gold microelectrode in flow-injection system. The samples are subjected by the same buffer solution and are injected in the flow-injection apparatus. By applying a novel square wave voltammetry method to perform as a sensitive method the voltamograms are recorded. The method used for determination of tamoxifen by measuring the changes in admittance voltammogram of a gold ultramicroelectrode (in 0.05 mol L(-1) H(3)PO(4) solution) caused by adsorption of the tamoxifen on the electrode surface. The best sensitivity was achieved using a frequency of 600 Hz and a medium composed of 0.05 mol L(-1) phosphate buffers at pH 2.0. The best performance was obtained with the pH value of 2, pulse amplitude 25 mV, frequency 600 Hz, accumulation potential of -100 mV and accumulation time of 0.5s. Furthermore, signal-to-noise ratio has 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. Calibration plots are given for solutions containing 1.0 x 10(-11) to 3.0 x 10(-6)mol L(-1) of tamoxifen. The detection limit is calculated to be 3.0 x 10(-12)mol L(-1) ( approximately 2 pg mL(-1)). The relative standard deviation at concentration 2.0 x 10(-8)M is 6.1% for five reported measurements.
authors.affiliation: Department of Chemistry, Center of Excellence in Electrochemistry, University of Tehran, 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
authors.forename: Hassan Ali
authors.initials: HA
authors.lastname: Zamani
mesh_terms: D000970:Antineoplastic Agents / Q000032:analysis* / Q000737:chemistry*; D002138:Calibration; D004563:Electrochemistry; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D010949:Plasma / Q000737:chemistry; D012680:Sensitivity and Specificity; D013607:Tablets / Q000032:analysis / Q000737:chemistry; D013629:Tamoxifen / Q000032:analysis* / Q000737:chemistry*; D014556:Urine / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D013607:Tablets; D013629:Tamoxifen