Analysis Of Copper Corrosion Inhibitor BTA And MBT In Circling Water

Based on the in-depth study of the current situation of copper corrosion inhibitor, we foundthat the copper corrosion inhibitor often need to compound used to increase the corrosion inhibitor effect.The complex compound of the benzotriazole (referred BTA) and mercaptobenzothiazole sodium (referred MBT) was a commonly used method. From learning a variety of methods of analysis and study the BTA and MBT,we found that no one has proposed analytical method of BTA and MBT simultaneously.In this paper, we used the UV spectrophotometry, first studied the analytical methods alone of BTA and MBT in the circulating water, then by studying its complex solution, the method for simultaneous determination of copper corrosion inhibitor is established. On this basis, we were studied the influence of other factors for the determination in the circulating cooling water system. Therefore. We draw the following conclusions:(1).The results show that, pH has a greater impact on the absorption wavelength and absorbance of BTA and MBT in the circulating water.1) In the range of pH11-13, we measured the absorbance of273.8nm and308.6nm respectively.Then we drew each standard curve of BTA and MBT. According to the absorbance at308.6nm and273.8nm of the sample in the circulating water system, as well as the respective standard curves,we could calculated the content of two copper corrosion BTA and MBT.2) In the range of pH4～6, we measured the absorbance of258nm and321nm respectively.Then we drew each standard curve of BTA and MBT. According to the absorbance at321nm and258nm of the sample in the circulating water system, as well as the respective standard curves,we could calculated the content of two copper corrosion inhibitor BTA and MBT.(2).With the increase of concentration, the absorption value is increased, and there was a linear relationship. According to the relationship of concentration and absorbance, we can eliminate the interference of inorganic salts on the method. (3). Used tap water to establish simulation and measured directly(do not adjust the pH of the water), we found that absorption peak of BTA at273.8nm,and accord to the peaks of BTA at alkaline conditions. However there was a big difference between the absorbance values. The pH value of the solution was adjusted to between water4-6, found that the absorption peak of BTA at258nm, and accord to the peaks of BTA at acidic conditions. The absorbance values were also consistent with the acidic conditions.(4). In the determination of the power plant water samples, we found no significant absorption peak at258nm. This absorption may be generated by salts. In the determination of BTA and MBT in the circulating water, the UV spectrophotometry operation is relatively simple, but many confounding factors will affect the accuracy of measurement results. Therefore this method suitable for the simultaneous determination of BTA and MBT in the circulating water when fewer interfering substances, or applied research the content of BTA and MBT when two copper corrosion inhibitor in circulating cooling in the water.