Fluorescence enhancement method for measuring anionic surfactants with a hydrophobic cyanine dye.
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.
Zhu
Chang-Qing
CQ
College of Chemistry and Materials Science, Anhui Normal University, 241000 Wuhu, China. zhucq625@163.com
Wu
Yu-Qin
YQ
Zheng
Hong
H
Chen
Jin-Long
JL
Zhuo
Shu-Juan
SJ
Li
Yong-Xin
YX
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
D000838:Anions; D001557:Benzenesulfonates; D002232:Carbocyanines; D012997:Solvents; D013501:Surface-Active Agents; C001114:dodecylbenzenesulfonic acid