Mihajlović Lj V, Mihajlović R P, Antonijević M M, Vukanović B V
Department of Chemistry, Faculty of Sciences, University of Kragujevac, Radoja. Domanovica 12, P.O.Box 60, 34000 Kragujevac, Serbia & Montenegro.
Talanta. 2004 Nov 15;64(4):879-86. doi: 10.1016/j.talanta.2004.03.061.
The possibility of applying natural monocrystaline pyrite as a sensor for the potentiometric titration of weak acids in N,N-dimethylformamide, methylpyrrolidone and pyridine was investigated. The potential of this electrode in N,N-dimethylformamide, methylpyrrolidone and pyridine exhibits a sub-Nernst dependence. In N,N-dimethylformamide the slope (mV/pH) is 39.0 and in methylpyrrolidone it is 45.0. The potential jumps at the titration end-point obtained in the titration of weak acids are higher than those obtained by the application of a glass electrode as the indicator electrode The potential in the course of the titration and at the titration end-point (TEP) are rapidly established. Sodium methylate, potassium hydroxide and tetrabutylammonium hydroxide (TBAH) proved to be very suitable titrating agents for these titrations. The results obtained in the determination of the investigated weak acids deviate by 0.1-0.35% with respect to those obtained by using a glass electrode as the indicator electrode.
研究了将天然单晶黄铁矿用作电位滴定N,N - 二甲基甲酰胺、N - 甲基吡咯烷酮和吡啶中弱酸的传感器的可能性。该电极在N,N - 二甲基甲酰胺、N - 甲基吡咯烷酮和吡啶中的电位呈现亚能斯特依赖性。在N,N - 二甲基甲酰胺中斜率(mV/pH)为39.0,在N - 甲基吡咯烷酮中为45.0。弱酸滴定中获得的滴定终点处的电位突跃高于使用玻璃电极作为指示电极时获得的电位突跃。滴定过程中和滴定终点(TEP)处的电位能迅速建立。甲醇钠、氢氧化钾和四丁基氢氧化铵(TBAH)被证明是这些滴定非常合适的滴定剂。使用所研究的弱酸进行测定时获得的结果与使用玻璃电极作为指示电极时获得的结果相比,偏差为0.1 - 0.35%。