title: Thermal modified Kaolinite as useful material for separation and preconcentration of trace amounts of manganese ions.
abstract: This work assesses for the first time the potential of natural Kaolinite as adsorptive material for preconcentration of metal traces. Manganese is quantitatively retained by 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) on thermal modified Kaolinite by column method in pH range of 8.5-10.0 at flow rate of 2mlmin(-1). Manganese was removed from column with 5.0ml of H(2)SO(4) 4moll(-1) and determined by flame atomic absorption spectrometric at 279.5nm. In this case, 0.lmug of manganese can be concentrated from 800ml of aqueous sample (where concentration is as low as 0.125mugl(-1)). Detection limit is 4.3mugl(-1) (3delta(bl)m(-1)) and analytical curve is linear in the 0.02-10mgl(-1) in final solution with correlation coefficient 0.9997 and relative standard deviation for eight replicate determination of 5mug of manganese in final solution is 0.71%. The interference of a large number of anions and cations has been studied in detail to optimize the conditions and method was successfully applied for determination of manganese in complex materials.
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, Kerman 7619817511, Iran.
authors.forename: Darush
authors.initials: D
authors.lastname: Afzali
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Taher
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
authors.forename: Sayed Ziae Mohammadi
authors.initials: SZ
authors.lastname: Mobarakeh