title: [UV-Vis spectroscopic characterization of Sudan series in organic solution].
abstract: The UV-Vis spectroscopic characterization of Sudan I, Sudan III and Sudan IV in nonpolar solvent ligarine, polar solvent acetonitrile, and acetonitrile-water mixture was studied. The characteristic absorption peaks of sudan series were a little red shifted in polar solvent compared to that in nonpolar solvent. In acetonitrile-water mixture the red shift of characteristic absorption peaks of sudan I and sudan III is respectively 13 and 8 nm, but the characteristic absorption peaks of sudan IV are red shifted before blue shifted. The increased adsorption strength of Sudan I, Sudan III and Sudan IV is 34.5%, 11% and 2.5% respectively. For these, the important reason is that the destroyed intramolecular hydrogen bond in Sudan series enlarges the scope of the pi delocalized bond in polar solvent.
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China.
authors.forename: Jin-ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Sheng-ke
authors.initials: SK
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Duan
authors.forename: Wen-ke
authors.initials: WK
authors.lastname: Wang