氯氮平的吸附伏安行为

Adsorptive Voltammetric Behavior of Clozapine

在０．１ｍｏｌ／ＬＮＨ４Ａｃ（ｐＨ７．８）底液中，氯氮平（ＣＬＰ）在汞电极上有一线性扫描还原峰，Ｅｐｃ＝－１．３４Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）．该峰具有明显的吸附性，吸附粒子为ＣＬＰ中性分子．测得ＣＬＰ在汞电极上的饱和吸附量为２．７×１０－１０ｍｏｌ／ｃｍ２，每个ＣＬＰ分子所占电极面积为０．６２ｎｍ２，ＣＬＰ在悬汞电极上的吸附符合Ｆｒｕｍｋｉｎ等温式．测得吸附系数β＝６．２８×１０５，吸引因素γ＝０．７５，电子转移数ｎ为２，不可逆吸附的转移系数α为０．５３．探讨了ＣＬＰ在汞电极上的还原机理，并建立了吸附溶出伏安法测定ＣＬＰ的最佳条件，检测限为８．０×１０－９ｍｏｌ／Ｌ．

In a supporting electrolyte containing 0 1 mol/L NH 4Ac(pH 7 8), a reduction peak of clozapine(CLP) was found by linear sweep voltammetry at Hg electrode. The peak shows a potential of -1 34 V( vs Ag/AgCl) and adsorptive characteristics. When the concentration of CLP is sufficiently low, the sweep rate is sufficiently rapid and the accumulation time is sufficiently long, the peak current is totally contributed by the reduction of the adsorbed CLP. The adsorbed species is most probably neutral molecules of CLP. The saturated adsorption amount of CLP at Hg electrode is 2 7×10 -10 mol/cm 2 and every CLP molecule occupies 0 62 nm 2. On the surface of HMDE, the adsorption of CLP obeys Frumkin adsorption isotherm. The adsorption coefficient is 6 28×10 5, the attractive factor is 0 75. The number of electrons transferred per CLP molecule, n , is 2 and the transfer coefficient of the irreversible adsorptive system of CLP is 0 53. The mechanism of electrochemical reduction of CLP at Hg electrode has been explored. The detection limit of the adsorptive stripping voltammetry of CLP is 8 0×10 -9 mol/L under optimum condition.