An efficient and selective flourescent optode membrane based on 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione as a novel fluoroionophore for determination of cobalt(II) ions.
ABSTRACT A novel fluorescence chemical sensor for the highly sensitive and selective determination of Co(2+) ions in aqueous solutions is prepared. The cobalt sensing system was prepared by incorporating 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione (L) as a neutral cobalt-selective fluoroionophore in the plasticized PVC membrane containing sodium tetraphenylborate as a liphophilic anionic additive. The response of the sensor is based on the strong selective fluorescence quenching of L by Co(2+) ions. At a pH 5.0, the proposed sensor displays a calibration curve over a wide concentration range of 5.0 x 10(-7) to 2.0 x 10(-2)M with a relatively fast response time of less than 5 min. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Co(2+) ion with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to the determination of cobalt content of vitamin B12 ampoule, cobalt cake, cobalt alloy and tap water samples.
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ABSTRACT: A novel fluorescence chemosensor based on 2,6-dicarbonylpyridine was designed and synthesized and its photophysical properties were characterized. Upon coordination of Co(2+) by the central 2,6-dicarbonylpyridinyl functional group, the chemosensor 2,6-bis(4-diphenylamino-styrylcarbonyl)pyridine (PhPy) showed nearly complete fluorescence quenching, while no fluorescence response was seen towards other competing cations. The experimental results show the chemosensor is highly selective and sensitive towards Co(2+) in the presence of competing ions, even in the ppb range. Job plot analysis was carried out and the results suggested that the binding of PhPy and Co(2+) was probably a 2 : 1 stoichiometry.The Analyst 12/2011; 136(24):5283-6. · 4.23 Impact Factor
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ABSTRACT: An optode system based on a plasticized polymer membrane containing cesium ion-selective fluoroionophore and lipophilic anions for the determination of cesium ions has been developed. In this work, 15-crown-5 derivative including anthracene was used as a fluoroionophore. Emission intensity of the optode membrane incorporating 15-crown-5-anthracene was measured at 500 nm with excitation at 360 nm in the presence of Tris-HCl buffer solution. Under optimum experimental condition, the relative fluorescence intensity was linear with the concentration of cesium ion in the range of 1.0 × 10(-4) M to 1.0 × 10(-1) M and the detection limit was obtained 4.2 × 10(-5) M, as defined by LOD=3 × S(b)/m (where S(b)=standard deviation of blank signal and, m=slope of the calibration curve). The effect of pH of sample solution on the fluorescent response, the selectivity, response time and reproducibility of the optode membrane were also discussed. The fluorescent optode system shows a high selectivity and sensitivity for cesium ion with respect to other cations such as K(+), Na(+) and Li(+).Journal of Fluorescence 11/2010; 21(2):747-51. · 1.79 Impact Factor