New Fluorescent Reagent Synthesis And Determination Of Metal Elements In Applied Research

More than 18,000 thousand kinds of chemicals have been included in Chemical Abstrat, tens of thousands of which have entered our environment. Some data show that about 3 to 4 Hundred million tons of poisonous substances enter the environment every year, a lot of which has done great harm to human health and ecological environment. Environmental pollution have been more and more widely concerned by all governments and people of the world. One of the characteristics of environment analytical chemistry, which is the necessary base of environmental chemistry, is to conduct quantitative analysis, demanding not only conventional index but also trace and ultratrace analysis, which becomes more and more important. The fluorescent monitor analytical method is widely used owing to its high sensitivity, fine selectivity, small sampling as well as its simplicity and high speed.One of the main directions of the development of environment analytical chemistry is to improve the sensitivity and selectivity of the analytical in order to energetically expand the space to the field of environment science. According to this objection and the characteristics of fluorescent analysis in itself, we developed a series of researches in the synthesis of special effective fluorescent reagents and interaction between reagents and poisonous metal elements. The paper falls into three parts:Part one: Synthesis and indication of R-NH-CS-NH-R'. In order to improve the sensitivity of the reagent, we must increase molecular conjugationand the co-planar effect of reagent by introducing salicylaldehyde and 2-hydroxy-1-naphthaldehyde at the spot of R when we design its structure. Thus the fluorescent intensity of the reagent are increased remarkably. Under these directions, we have synthesized four kinds of R-NH-CS-NH-R' and indicated them.Part two: According to Lewis' theory of acids and bases and the characteristic structure of R-NH-CS-NH-R', which includes atoms of N and atoms of S that have strong complexation and can form steady complexes between reagents and metal ions, we established the fluorescent quenching analytical method of Pb,Ete,Cd in food and water.Part three: Synthesis of three rhodanine derivative. When we conducted molecular design, we increased reagent's solubility in solution by adding hydrophilic groups and increase molecular conjugation by introducing structures of salicylaldehyde, 2-hydroxy-1-naphthaldehyde and anisaldehyde. We studied and indicated their nature and measured dissociation constants of different reagents.