A rapid method for determination of acid value in transformer oil by PPy modified electrode
来源期刊：中南大学学报(英文版)2014年第6期
论文作者：XIONG Ying(熊英) HE De-liang(何德良) FENG Yong(冯勇) ZHOU Zhou(周舟) CHANG Xin-yuan(常新园) LIU Fu-rong(刘芙蓉)
文章页码：2202 - 2207
Key words：acid value; voltammetry; polypyrrole-modified electrode; transformer oil
Abstract: A polypyrrole-modified glassy carbon electrode (PPy/GC electrode) was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry (LSV). A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value (AV) of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg(KOH)·g-1, with a sensitivity of 39.42 μA0.5/(mg(KOH)·g-1) and the detection limit of 0.0014 mg(KOH)·g-1 (signal-to-noise ratio is 3, standard deviation is 2.247%). Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.
XIONG Ying(熊英)1, HE De-liang(何德良)1, FENG Yong(冯勇)1, ZHOU Zhou(周舟)2, CHANG Xin-yuan(常新园)1, LIU Fu-rong(刘芙蓉)1
(1. College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China;
2. Hunan Electric Power Corporation Research Institute, Changsha 410007, China)
Abstract:A polypyrrole-modified glassy carbon electrode (PPy/GC electrode) was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry (LSV). A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value (AV) of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg(KOH)·g-1, with a sensitivity of 39.42 μA0.5/(mg(KOH)·g-1) and the detection limit of 0.0014 mg(KOH)·g-1 (signal-to-noise ratio is 3, standard deviation is 2.247%). Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.
Key words:acid value; voltammetry; polypyrrole-modified electrode; transformer oil
