Zeng Baizhao, Yang Yuxia, Ding Xiaogang, Zhao Faqiong
Department of Chemistry, Wuhan University, Wuhan 430072, China.
Talanta. 2003 Dec 23;61(6):819-27. doi: 10.1016/S0039-9140(03)00381-3.
A novel method for the determination of perphenazine has been developed. The method is based on the accumulation of perphenazine at a gold electrode modified with decanethiol (DEC) self-assembled monolayer (SAM) and its oxidation at about 0.6 V (vs. saturated calomel electrode (SCE)). Because some coexistent electroactives were blocked and perphenazine was selectively accumulated by the SAM, the electrode exhibited good selectivity and sensitivity. Various conditions were optimized for practical application. Under the selected conditions (i.e. 0.05 M pH 10 sodium borate buffer, accumulation time: 120 s, accumulation potential: -0.4 V, scan rate: 100 mV s(-1)), the anodic stripping peak current was linear to perphenazine concentration in the ranges of 6x10(-9)-5xl0(-7) and 5x10(-7)-5x10(-6) M with correlation coefficients of 0.998 and 0.995, respectively. For a 1.0x10(-6) M perphenazine solution, the relative standard deviation of peak height was 2.3% (n=8). This method was applied to the determination of perphenazine in some drugs and the recovery was 92-101%. In addition, it was found that in the presence of perphenazine, the SAM structure changed a little and more needle holes appeared. However, the SAM could recover the original form when perphenazine and its redox product were removed from the monolayer by repeatedly cycling the electrode in a blank solution for a minute. The modified electrode was characterized by alternating current impedance and electrochemical probe.
已开发出一种测定奋乃静的新方法。该方法基于奋乃静在癸硫醇（DEC）自组装单层（SAM）修饰的金电极上的积累及其在约0.6 V（相对于饱和甘汞电极（SCE））的氧化。由于一些共存的电活性物质被SAM阻断且奋乃静被选择性积累，该电极表现出良好的选择性和灵敏度。针对实际应用对各种条件进行了优化。在选定条件下（即0.05 M pH 10硼酸钠缓冲液、积累时间：120 s、积累电位：-0.4 V、扫描速率：100 mV s⁻¹），阳极溶出峰电流在6×10⁻⁹ - 5×10⁻⁷和5×10⁻⁷ - 5×10⁻⁶ M范围内与奋乃静浓度呈线性关系，相关系数分别为0.998和0.995。对于1.0×10⁻⁶ M的奋乃静溶液，峰高的相对标准偏差为2.3%（n = 8）。该方法应用于某些药物中奋乃静的测定，回收率为92 - 101%。此外，发现存在奋乃静时，SAM结构略有变化且出现更多针孔。然而，当通过在空白溶液中反复循环电极一分钟从单层中去除奋乃静及其氧化还原产物时，SAM可恢复原始形态。通过交流阻抗和电化学探针对修饰电极进行了表征。
