Research On Simultaneous Determination Of Lead And Cadmium By Using The Multiple Linear Regression Ion-Selective Electrode

The ion selective electrode is a new and active branch in the potentiometry field in recent thirty years.Because of its special advantage,such as easy,rapid,fitful to analyse on the spot and not ruin the water sample,it has been widely used in the study of chemistry sciences ,environment sciences and medical sciences,etc.The technology provides efficient method for resolving some difficult problems in analytical chemistry field.For all that,the interference in determination arose from accompanying ions has been restricting the wide use of ion selective electrode.Traditional method for resolving the problem is adding chemistry concealment.However,the procedure of operation is complex,wasteful and it may bring new interference,at the same time,the determination is limited to single ion,so its efficient of determination is pool.In face of above problems,the research adopts ion selective electrode to determine accompanying interactional ions of Cd²⁺ and Pb²⁺.Meanwhile,combing MATLAB and EXCEL language of computer the research determines two component by using the multiple linear regression analysis to ion-selectrode.The best work conditions determining Cu²⁺ Cd²⁺ Pb²⁺with ion-selectrode are studied.The emphasis is pH value,TISAB,temperature and response-time of water sample which are effect factors on ion-selectrode.The research shows determining Cu²⁺ Cd²⁺and Pb²⁺ pH value will be controlled about 5～5.5, TISAB will adopt 0.1mol/L KNO3,temperature will be kept constant(25～300C) and response-time is less than two minutes. The linear range of regression equations are tested.Without interference,three ions'linear range are 10-3～5×10^-7mol/L.Different concentration grades 64 mix solutions are compounded.and they are determined with Cd²⁺ ion-selectrode and Pb²⁺ ion-selectrode.According to response-values and concentration,two linear regression equations are built by using the multiple linear regression analysis to ion-selectrode combing MATLAB and EXCEL language of computer.Potentionmetric of ten water samples compounded by myself are determined.By regression equations and computer procedure , the concentration of five water samples are worked out.RE% is within 10%,meanwhile ,using the method determines Cd²⁺ and Pb²⁺ concentration of true industrial waste water from a factory,and the result is compared with one of Atomic Absorption Spectrophotometry.Disparity of the...