title: Simple regression model using an optode for the simultaneous determination of zinc and cadmium mixtures in aqueous samples.
abstract: An optical-fiber chemical sensor (optode) is described for the simultaneous determination of Zn2+ and Cd2+ mixtures using 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol immobilized onto XAD-4 (Br-PADAP/XAD-4). A simultaneous analysis was achieved by using a single-wavelength kinetic approach coupled with a regression model. Here, the regression model was derived for the slope response of Br-PADAP/XAD-4 to binary mixtures of the metal ions, Zn2+ and Cd2+, at pH 8. The model was used then to predict the concentration of one metal ion while the other was kept constant. This was found to be reasonably successful for Zn2+ and Cd2+, with deviations of 3% and 10%, respectively. The sensor was also found to provide excellent sensitivity for both metal ions with excellent LODs (< 0.1 ppm) and very short analysis times (< 30 s).
authors: Department of Chemistry, University of Jember, Indonesia. b_kuswandi@hotmail.com
authors: B
authors: B
authors: Kuswandi
authors: A A
authors: AA
authors: Vaughan
authors: R
authors: R
authors: Narayanaswamy
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D002104:Cadmium / Q000032:analysis*; D002852:Chromatography, Ion Exchange; D007202:Indicators and Reagents; D012044:Regression Analysis; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
chemical_list: D001391:Azo Compounds; D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical; D002104:Cadmium; C037882:2-(5-bromo-2-pyridylazo)-5-diethylaminophenol; D015032:Zinc