title: Electrochemical determination of 6-mercaptopurine at silver microdisk electrodes.
abstract: The electrochemical behaviour of 6-mercaptopurine (6-MP) at a microdisk electrode is investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that 6-MP can be strongly adsorbed on the surface of the static mercury drop electrode (SMDE) and reacts with Ag+ ions which are produced at positive potentials. 6-MP yields a well-defined cathodic stripping signal during the negative scan at about -0.812 V (vs. SCE) in pH 9.0 phosphate buffer solution. The electrode has hence been used for the determination of 6-MP by differential pulse voltammetry (DPV). The linear range is between 2.0x10(-7) and 5.0x10(-5) mol/l, with the calculated detection limit (S/N=3) of 8.0x10(-8) mol/l. The relative standard deviation is 3.0% for eight successive determinations of 4.0x10(-5) mol/l 6-MP. The determination of 6-MP in tablets has also been carried out and satisfactory results have been obtained.
authors.affiliation: School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China. limaoguo@263.net
authors.forename: Mao-Guo
authors.initials: MG
authors.lastname: Li
authors.forename: Yin-Ling
authors.initials: YL
authors.lastname: Wang
authors.forename: Guang-Feng
authors.initials: GF
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Fang
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D015122:Mercaptopurine / Q000032:analysis*; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver; D015122:Mercaptopurine