Abstract: A fluoride ion (F?) colorimetric sensing polyimide (PI) film, a preparation method therefor and application thereof; the preparation method for a F? colorimetric sensing polyimide film comprises: mixing an aromatic diamine monomer and an aromatic dianhydride monomer in a strong polar aprotic organic solvent, adding a catalyst, vacuumizing at room temperature-introducing argon repeatedly for multiple times, and then reacting same under the protection of argon to obtain a polyimide solution; then preparing a PI fiber; dissolving the PI fiber in the strong polar aprotic organic solvent, thoroughly stirring to dissolve same and then applying same evenly on a clean glass plate, removing the solvent, cooling, then soaking same in hot water for film stripping so as to obtain the F? colorimetric sensing PI film.

Abstract: The present invention relates to a new kind of heavy metal chelating agents and a preparation process and uses thereof. The said heavy metal chelating agents are expressed in &agr;-[D(+)glucose-1-yl-amino]-&bgr;3-mercapto-(S)-propanoic acid (abbreviated to NGP,I) and/or N,N′-di[D(+)glucose-1-yl]-L-cystine (abbreviated to NGCD,II). In the process of preparation, glucose and cysteine are reacted with a base, with a reducing agent, and the obtained products are acidified to give NGP,I, which can be used in and/or as drugs, health foods and food additives for accelerating the excretion of heavy metals including Pb, Cd, Hg, Al, Sb, As, etc. The structural feature of the compounds of the present invention is that they contain glucose and cysteirie in their molecules.