title: Fluorescence enhancement method for measuring anionic surfactants with a hydrophobic cyanine dye.
abstract: A novel fluorimetric method based on use of a hydrophobic cationic cyanine dye has been developed for determination of the anionic surfactant sodium dodecylbenzenesulfonate (DBS). The method is based on the enhancement effect of DBS on the fluorescence of the hydrophobic cyanine dye 2-[-4'-chloro-7'-(1"-ethyl-3",3"-dimethylindolin-2"-ylidene)-3',5'-(propane-1"',3"'-diyl)-1',3',5'-heptatrien-1'-yl]-1-ethyl-3,3-dimethyl-3 H-indolium iodide. Under the optimum conditions the extent of fluorescence enhancement is proportional to the concentration of DBS in the range 0.05-5.0 mg L(-1); the detection limit is 0.014 mg L(-1). The relative standard deviation for 0.35 mg L(-1) DBS was 1.1% (n=10). The proposed method, which avoided use of toxic solvents and tedious solvent-extraction, and was applied to the determination of DBS in natural water with recoveries between 99.9 and 107%. Preliminary research shows that the fluorescence enhancement is due to the formation of a dye aggregate facilitated by DBS.
authors.affiliation: College of Chemistry and Materials Science, Anhui Normal University, 241000 Wuhu, China. zhucq625@163.com
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Zhu
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Wu
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Chen
authors.forename: Shu-Juan
authors.initials: SJ
authors.lastname: Zhuo
authors.forename: Yong-Xin
authors.initials: YX
authors.lastname: Li
mesh_terms: D000838:Anions / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry*; D002232:Carbocyanines / Q000737:chemistry*; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000838:Anions; D001557:Benzenesulfonates; D002232:Carbocyanines; D012997:Solvents; D013501:Surface-Active Agents; C001114:dodecylbenzenesulfonic acid