Modified Electrodes In The Detection Of Trace Heavy Metal Ions Modified

Heavy metals is extremely dangerous pollutants in water. It is dangerous to human andother living organisms.hence, It is of great significant to develop a rapid, accurate, sensitiveand convenient method to determine trace heavy metals. Compared with other heavy metaldetection methods, electrochemical detection method exhibit the merits of its fastmulti-element capabilities, simple operation and high sensitivity which plays an importantrole in the detection of trace amounts of heavy metals In this paper, we use theFTO(Conductive glass), Bi-FTO, HAP-FTO as a working electrode. Heavy metal Cd2+andPb2+are determined by differential pulse anodic stripping voltammetry. The conclusion is asfollows:(1)FTO as working electrode which was used for voltammetric detection of Cd2+andPb2+. The effects of deposition potential and time, and increment were investigated andfindings that when the deposition potential and the time was-1.0V and360s, the amplitudeis50mV, the Cd2+and Pb2+show the highest sensitivity; the linear concentration windows ofPb2+and Cd2+are0.2-1.0mg/L and0.5-2.5mg/L.The detection limit is1.26×10-3mg/L and0.84×10-3mg/L(2)The FTO was modified with bismuth film electrode, we studied them the influencesof deposition time, deposition potential and amplitude detection of heavy metal ions, too.Wefind the best deposition potential, deposition time and amplitude were still-1.0V,360s and50mV; The linear concentration windows of Pb2+and Cd2+were0.05-0.25mg/L and0.1-0.5mg/L. Compared with the FTO electrode, The detection limit is0.44×10-3mg/L and0.51×10-3mg/LBismuth film can improve Pb2+and Cd2+detection sensitivity significantly.(3)We use TiO2as a binder, using hydroxyapatite modified FTO as working electrode.We studied the effect of heat treatment conditions and amount of investigated binder on thetest results. The results showed that: when the amount of TiO2is30μL, heat it at450℃for16min, we obtain better Pb2+and Cd2+detection sensitivity. The linear concentration windowsof Pb2+and Cd2+were0.03-0.15mg/L and0.15-0.75mg/L. The detection limit is0.41×10-3mg/L and0.44×10-3mg/L.Compared with the FTO electrode, HAP-FTO can improve Pb2+and Cd2+detection sensitivityan significantly.In this paper, FTO was modified with bismuth film and hydroxyapatite as the workingelectrode, establishing a rapid and high sensitivity electrochemical detection method for Pb2+and Cd2+. This study is the practical application of electrochemical detection of heavy metalions in solution and lay a solid experimental basis, and provide some theoretical guidance.