title: A sequential injection method for the determination of Tween-80 in natural water samples using a fluorescence enhancement of the dye Eosin-B.
abstract: A simple sequential injection (SI) method is reported for the determination of the non-ionic surfactant polyoxyethylene sorbitan monoleate (Tween-80). The proposed method is based on a fluorescence enhancement of the probe 4',5'-dibromo-2',7'-dinitro fluorescein, disodium salt (Eosin B) in the presence of a surfactant. The procedure is optimized using the univariate method of optimization. The optimum operating conditions are as follows: reagent concentration, 40 ppm; pH, 4.5; aspirated volumes of sample and reagent, 120 microL and 100 microL, respectively. With the optimum conditions described, linear calibration curves were obtained from 10-200 ppm. The detection limit was 1.7 ppm and the maximum relative standard deviation of the method was 2.7% (n = 5). The fluorescence excitation and emission were fixed at lambda(ex) = 545 mn and lambda(em) = 585 nm. The method was successfully applied to the determination of (TW-80) in natural water samples.
authors.affiliation: Department of Chemistry, College of Science, Sultan Qaboos University, Box 36, Al-Khod 123, Sultanate of Oman. alkindy@squ.edu.om
authors.forename: Salma M Z
authors.initials: SM
authors.lastname: Al-Kindy
authors.forename: Fakhr Eldin O
authors.initials: FE
authors.lastname: Suliman
authors.forename: Salama B
authors.initials: SB
authors.lastname: Salama
authors.forename: Mohamed
authors.initials: M
authors.lastname: Aoudia
authors.forename: Seif N
authors.initials: SN
authors.lastname: Al-Bahry
authors.forename: Hamoud S
authors.initials: HS
authors.lastname: Al-Bahlany