title: Design of a novel optical sensor for determination of trace gadolinium.
abstract: In this work, a highly selective and sensitive gadolinium (Gd) optical sensor based on immobilization of bis(thiophenal) pyridine-2,6-diamine (BPD), on a triacetylcellulose membrane has been reported. This optode exhibits a linear range of the Gd(III) ion concentration of 2.5 x 10(-6)M with a detection limit of 0.93 x 10(-8) M. Response time of the newly designed optode was within 1-2 min, depending on the Gd(III) ion concentration. Response of the sensor is independent of solution pH in the range of 2.0-9.0. It manifests advantages of: low detection limit, fast response time, and most significantly, very good selectivity with respect to a number of lanthanide ions (La, Ce, Sm, Tm, Ho, and Eu ions). The sensor was successfully regenerated with thiourea solutions and its response was reversible and reproducible (R.S.D. less than 1.4%). This optode was applied to determine Gd(III) in synthetic and water samples, and validated with certified reference materials (CRMs).
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Zare-Dorabei
authors.forename: P
authors.initials: P
authors.lastname: Norouzi
authors.forename: M R
authors.initials: MR
authors.lastname: Ganjali
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D002623:Chemistry Techniques, Analytical; D005682:Gadolinium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008956:Models, Chemical; D055095:Optics and Photonics; D011108:Polymers / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D015203:Reproducibility of Results; D045483:Rivers; D058924:Thienopyridines; D013876:Thiophenes / Q000737:chemistry*; D013890:Thiourea / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D007477:Ions; D011108:Polymers; D011725:Pyridines; D058924:Thienopyridines; D013876:Thiophenes; D014874:Water Pollutants, Chemical; C546374:bis(thiophenal)pyridine-2,6-diamine; C520056:poly(2,6-pyridinediamine); D014867:Water; D002482:Cellulose; C024671:cellulose triacetate; D005682:Gadolinium; D013890:Thiourea