Study On Simulataneous Determination Of Poisonous Heavy Metal Ions By Multiwave Spectrophotometry

With the development of industrial and agricultural production, the products with poisonous heavy metal are used extensively. Therefore, it has caused people's great attention to the mankind's security question. Spectrophotometry is widely used in heavy metal analysis, which advantage is instrument simple, wide analytical range, good precision and accuracy. However, working of chemical separation must be need before determining when sample contain some coexist metal ions. In recent years, there is more research of the method of the chemometrics in simultaneous determination of multicomponents, but other interference ion usually needs preliminary separation, which can not really achieve the goal of measuring quickly.Four kinds of poisonous metal ion (Cu~2+, Cd~2+,Pb~2+,Hg~2+) can be determined directly without chemical separation under nine kinds of common coexist metal ion in this paper, this article introduces the following research: 1. We determine directly content of the metal ion in an aqueous medium with not extracting under the existence of tritonX-100 and β-cyclodextrin. 2.The necessary compromise conditions for the coloration of all of the copper, cadmium, lead and mercury ions using dithizone in the presence of surfactant for their simultaneous determination have been optimized. 3. Comparison of the three chemometrics methods (i.e. P-matrix, Principal component regression, Kalman filtering) with above color systems for the simultaneous determination of the cited four cations have been carried out. It was found that of the three chemometrics methods, Principal component regression, Kalman filtering are well suitable for the mixtures. The result of Cu~2+ and Hg~2+ is better and rate of recovery is close to 100%. The RSD for Cu~2+ is 3.66% and 3.24% separately and the RSD for Hg~2+ is 1.50% and 1.03% separately. Some samples of Cu~2+and Hg~2+have certain errors. However, all results can reflect the information in mixing solution.The use of room temperature ionic liquids as an alternate solvent to replace tradition organic solvents in liquid/liquid extraction of heavy metal ions was introduced in the other part of this paper. We use l-butyl-3-methylimmidazolium hexafluorophosphate as extractant which can dissolve more metal-dithizonate and donot dissolve each other with water, and investigated the resulted from pH of solutions and different metal ion, the results suggested that the extraction ability of [bmim]PF6 is strong , the result is better, and it can eliminate the environmental pollution brought from volatile extraction solvents from its source.