氟哌酸伏安行为的研究

STUDIES ON VOLTAMMETRIC BEHAVIOUR OF NORFLOXACIN

在０．０５ｍｏｌ·Ｌ－１ＮＨ４Ｃｌ溶液中，富集电位－１．１０Ｖ（Ａｇ／ＡｇＣｌ）、富集时间１２０ｓ、扫速１２０ｍＶ·ｓ－１时，氟哌酸出现一吸附伏安还原峰，峰电位为－１．４８Ｖ．用线性扫描与循环伏安法、交流极谱和恒电位库仑法等手段研究体系的伏安行为及电极反应机理．测得扩散系数Ｄ＝９．３８×１０－７ｃｍ２·ｓ－１，电极反应电子数ｎ＝２，电子转移因数α＝０．５１，参与电极反应Ｈ＋数ｘ＇＝１．体系吸附符合Ｆｒｕｍｋｉｎ吸附等温式，吸附因数β＝３．２×１０５，吸引因数α＝１．２，吸附自由能ΔＧ°＝－３１．４ＫＪ·ｍｏｌ－１，实验表明，体系属不可逆吸附波．

In0.05mol·L-1NH4Cl solution,a voltammetric reduction peak of norfloxacin was obtained by adsorptive voltammetry after accumulation of 120s at initial potential -1.10V(Ag/AgCl).The peak potential was -1.48V.The voltammetric behaviour of the system and its electrode reaction mechanism were studied by means of linear sweep and cyclic voltammetry,AC polarography and constant-potential coulometry,etc.The diffusion coefficient D was 9.38×10-7cm2·s-1,the number of electrons transferred was 2 and the tranfer coefficient αwas 0.51,the number of H+ was 1.The adsorption of the system obeys Frumkin adsorption isotherm.The adsorption coefficient βwas 3.2×105,the interaction factor αwas 1.2 and the adsorption free energy was-31.4kJ·mol-1.The system was a irreversible adsorption wave.