摘要
在非电活性的阳离子表面活性剂十二烷基二甲基苄基氯化铵(1227)中加入镉(Ⅱ),1227浓度对镉(Ⅱ)峰电流明显影响,镉(Ⅱ)作为指示离子,可测定微量阳离子表面活性剂的浓度。影响机理为配离子CdCl+和1227的阳离子(R+)都在阴极上吸附,CdCl+吸附使峰电流增大,R+吸附使峰电流减小。CdCl+吸附快,R+吸附慢。利用Oring 7.0拟合出1227存在下镉(Ⅱ)的还原峰电流数学模型。通过Origin 7.0非线性拟合出了CdCl+与R+的吸附常数和促进因子,对复杂吸附过程峰电流可进行定量计算。该方法为相对标准偏差(n=5)为2.2%,加标回收率为96.8%。
It was found that by the addition of a definite amount of CA（ Ⅱ ） ion, the non-electroactive cationic surfactant, dodecyl dimethyl benzyl ammonium chloride or designated as 1227, in microamounts, was determined by square wave polarography. Value of peak current of Cd （Ⅱ） ion （called the indicative ion） increases with the increase of concentration of 1227 in a definite range. Mechanism of the reaction at the working electrode was somewhat complex, composing the fast adsorption of the cationic CdCl＋ ion and slow adsorption of the cation of 1227, R＋ on the cathode, leading to increase of peak current in the former case and decrease of peak current in the latter case. Mathematical model of reduction peak current of Cd（ Ⅱ ） ion in the presence of 1227 was obtained by simulation with the program Origin 7.0. And also by the NLSF simulation with Origin 7.0, Values of adsorption constants and affecting factors of the cations CdCl＋ and R＋ were found, and values of peak current of the complex adsorption process were calculated quantitatively. Value of RSD （n=5） of this method was found to be 2. 2%, and result of recovery test obtained by standard addition method were 96. 8%.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2010年第1期17-19,共3页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
国家自然科学基金资助项目(50574006)
