Study On The Chromogenic Reaction And Application Of Two Lactone Dyes With Metal Ions

Chapter 1:The concept,types and properties of leuco dyes were briefly introduced in this chapter.The mechanism of chromogenic reaction and research status of the fluoran dyes was introduced mainly.At the same time,it also gived a detailed introduction of the research progress in the field of detection of trace iron.Chapter 2:Firstly,the chromogenic reaction of lbc-25 and 15 kinds of metal ions were studied.It was found that Fe³⁺had the best coloration effect on lbc-25.Next,the absorption spectra of lbc-25 with Fe³⁺was studied,it was found that lbc-25 produced two absorption peaks at 464 nm and 600 nm,and its molar absorption coefficient?_464nm64nm is 1.08×10³ L·mol^-1·cm^-1,?_600nm00nm is0.88×10³ L·mol^-1·cm^-1.The complexation ratio of lbc-25 and Fe³⁺is 1:2 and the instability constant is 7.6×10^-66 at 464 nm.The above experiments provide a theoretical basis for the further applied research.Chapter 3:The spectral behavior of ck-16 and 15 kinds of metal ions were studied by a qualitative methods,and the most sensitive chromogenic agent is Fe³⁺according to the experimental results.Then their absorption spectra were examined and it was found that ck-16 has a strong absorption peak at534 nm,and its molar absorption coefficient?_534nm34nm is 1.3×10⁴ L·mol^-1·cm^-1.The experimental results showed that the complex ratio of ck-16 to Fe³⁺was1:1 and the instability constant is 4.9×10^-7.Comparing the two fluoran dyes,it was found that ck-16 is more sensitive to Fe³⁺than lbc-25,and the insability constant of ck-16 is smaller than lbc-25.Therefore,the color reaction of ck-16 is more promising than that of lbc-26.Chapter 4:Due to the high selectivity and high sensitivity of ck-16 to Fe³⁺,it is proposed to establish a new spectrophotometric method for the detection of trace iron in medicines.The ck-16 and Fe³⁺would generate a stable red complexes in ethanol systems,The maximum absorption wavelength of the complex is 534 nm.Iron content is consistent with Lambert-Beer law in the range of 0.5 to 100 ug/g,and the correlation coefficient R² is 0.991.This method was applied to the determination of trace iron in heme.The content of iron in heme was 32.00 ug/g,and the recovery was 98.5%.The method is higher sensitivity compared with phenanthroline spectrophotometry,and it avoids the problem of unfavorable standard linearity due to oxidation of Fe²⁺with air in the method of phenanthroline spectrophotometry.Chapter 5:The application of ck-16 to the color reaction of Fe³⁺was extended and a water-induced fading whiteboard pen ink was prepared in this chapter.The ink was composed of solvent?ethanol?,colorant?fluoran dyes?,developer(Fe³⁺),binder?polyvinyl butyral,PVB?,surfactant?OP-10?and a amount of cyclodextrin.The prepared ink has smooth writing,stable performance,no irritating odor,and it can be faded with clear water.The whiteboard pen ink has a simpler formulation,a lower cost,and better writing performance compared with the currently available whiteboard pen ink.Finally,All the experimental results were summarized and further works were proposed as well.