title: Natural analcime zeolite modified with 5-Br-PADAP for the preconcentration and anodic stripping voltammetric determination of trace amount of cadmium.
abstract: A procedure for separation and preconcentration of trace amounts of cadmium has been proposed. A column of analcime zeolite modified with benzyldimethyltetradecylammonium chloride and loaded with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) was used for retention of cadmium. The cadmium was quantitatively retained on the column at pH approximately 9 and was recovered from column with 5 ml of 2 M nitric acid with a preconcentration factor of 140. Anodic stripping differential pulse voltammetry was used for determination of cadmium. A 0.05 ng/ml detection limit for the preconcentration of aqueous solution of cadmium was obtained. The relative standard deviation (RSD) for eight replicate determinations at the 1 microg/ml cadmium levels was 0.31% (calculated with the peak height obtained). The calibration graph using the preconcentration system was linear from 0.01 to 150 microg/ml in final solution with a correlation coefficient of 0.9997. For optimization of conditions, various parameters such as the effect of pH, flow rate, instrumental conditions and interference of number of ions, were studied in detail. This method was successfully applied for determination of cadmium in various complex samples.
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran. darush_afzali@yahoo.com
authors.forename: Darush
authors.initials: D
authors.lastname: Afzali
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Taher
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Rezaeipour
authors.forename: Mohammad
authors.initials: M
authors.lastname: Khayatzadeh Mahani
mesh_terms: D000497:Alloys; D001391:Azo Compounds / Q000737:chemistry*; D049872:Bivalvia / Q000737:chemistry; D002104:Cadmium / Q000032:analysis*; D002138:Calibration; D002708:Chlorella / Q000737:chemistry; D004563:Electrochemistry; D007202:Indicators and Reagents; D010944:Plants / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000032:analysis; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000497:Alloys; D001391:Azo Compounds; D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical; D002104:Cadmium; D017641:Zeolites; C037882:2-(5-bromo-2-pyridylazo)-5-diethylaminophenol