二硝基番木鳖碱在汞电极上的电化学行为及其应用  

ELECTROCHEMICAL BEHAVIOR OF DINITROSTRYCHNINE AT Hg ELECTRODE AND ITS APPLICATION

作　　者：李美仙[1] 胡乃非[1] 林树昌[1] 

机构地区：[1]北京师范大学化学系

出　　处：《北京师范大学学报（自然科学版）》1995年第4期491-495,共5页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金

摘　　要：在０．０２ｍｏｌ·Ｌ－１ＨＡｃ－ＮａＡｃ，ｐＨ４．０的底液中，二硝基番木鳖碱（ＤＮＳ）在汞电极上有一不可逆线性扫描还原峰，（ｖｓ．饱和Ａｇ／ＡｇＣｌ电极）。该峰具有明显吸附性。当ＤＮＳ浓度较小，扫描较快，搅拌富集时间较长时，电极反应完全为吸附态的ＤＮＳ的还原所控制，吸附型体为ＤＮＳ中性分子。测得ＤＮＳ在汞电极上的饱和吸附量为２．７５×１Ｏ－１１ｍｏｌ·ｃｍ－２，每个ＤＮＳ分子所占电极面积为６．０４ｎｍ２。探讨了吸附伏安法测定ＤＮＳ的最佳条件。可将非电活性的番木鳖碱硝化转化为ＤＮＳ，然后用吸附伏安法对番木鳖碱进行间接测定。In a supporting electrolyte containing 0.02 mol·L-1 HAc-NaAc,PH4.0,an irreversible reduction peak of dinitrostrychnine(DNS) was found by linear-sweep voltammetry at Hg electrode.The peak showed a potential of -0.28V(vs.Ag/AgCl) and adsorptive characteristics.When the concentration of DNS is sufficiently low,the sweep rate is sufficiently fast and the preconcentration time is sufficiently long,the peak current is totally contributed by the reduction of adsorbed DNS at Hg electrode.The adsorbed species is most probably neutral molecule of DNS.The amount of saturated adsorption of DNS on Hg surface is 2.75×10-11 mol·cm-2 and every DNS molecule occupies 6.04 nm2.The optimized conditions for the determination of DNS by adsorptive stripping voltammetry were found.The electroinactive strychnine can be transformed into DNS after reacted with HNO3,and then be indirectly measured by adsorptive stripping voltammetry.

关 键 词：番木鳖碱 二硝基番木鳖碱 汞电极 电分析化学 

分 类 号：O629.3[理学—有机化学] O657.1[理学—化学]