A wall-jet disc electrode for simultaneous and continuous on-line measurement of sodium dithionite, sulfite and indigo concentrations by means of multistep chronoamperometry
A wall-jet disc electrode for simultaneous and continuous on-line measurement of sodium dithionite, sulfite and indigo concentrations by means of multistep chronoamperometry
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壁射流圆盘电极，用于通过多步计时安培法同时连续在线测量连二亚硫酸钠、亚硫酸盐和靛蓝浓度
DOI：
10.1016/s0003-2670(03)00500-2
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发表时间：
2003
影响因子：
6.2
通讯作者：
P. Kiekens
中科院分区：
文献类型：
--
作者：
E. Gasana;P. Westbroek;E. Temmerman;H. Thun;P. Kiekens
本文提出了一种多步计时电流法同时连续测定靛蓝、连二亚硫酸钠和亚硫酸盐浓度的方法。该方法基于连二亚硫酸钠的氧化和靛蓝在铂盘电极上的还原形式。连二亚硫酸钠在相对于Ag/AgCl为0.3V的电势下被氧化，并且在旋转盘电极和壁喷射电极处显示出传输控制的稳态电流。后者是为应用程序的目的而开发的。壁喷射代替旋转盘电极的实施更容易且成本有效。靛蓝在− 0.55 V（相对于Ag/AgCl）下氧化为几乎不溶于水的产物，该产物在电极表面沉淀。靛蓝表现为准可逆性，在相对于Ag/AgCl的− 0.9 V电位下还原。为了清洁电极表面，该还原被用作多步骤序列中的一个步骤。最后，亚硫酸盐在相对于Ag/AgCl为0.8V的电位下被氧化，但没有产生明确的运输控制极限电流。然而，其浓度的测定仍有可能在5%的误差范围内。
In this paper, a multistep chronoamperometric method is presented to measure continuously and simultaneously the concentrations of indigo, sodium dithionite and sulfite for application in textile dyeing processes. The method is based on the oxidation of sodium dithionite and the reduced form of indigo at a platinum disc electrode. Sodium dithionite is oxidized at a potential of 0.3V versus Ag/AgCl and shows transport controlled steady state currents at a rotating disc electrode and a wall-jet electrode. The latter has been developed for the purpose of the application. Implementation of a wall-jet instead of a rotating disc electrode is much easier and cost-effective. Indigo is oxidized at −0.55V versus Ag/AgCl to a virtually water insoluble product, which precipitates at the electrode surface. Indigo behaves quasi-reversibly, and is reduced at a potential of −0.9V versus Ag/AgCl. In order to clean the electrode surface this reduction is used as a step in the multistep sequence. Finally, sulfite is oxidized at a potential of 0.8V versus Ag/AgCl but did not give rise to well defined transport controlled limiting currents. However, determination of its concentration is still possible within error margins of 5%.