Separation and preconcentration of Ag(I) in aqueous samples by flotation as an ion-associate using iodide and ferroin followed the determination by flame atomic absorption spectrometry.
A simple method for separation/preconcentration and determination of Ag(I) in aqueous samples is described. The method is based on formation of an ion-associate between Ag(I)-iodide complex and ferroin, which can be floated at the interface of the aqueous/n-heptane phases. The flotation process was carried out using 500-ml aliquot of the aqueous solution and the floated layer was dissolved in 5 ml of 1 M HNO3 containing methanol (50% v/v) as the solvent. The Ag(I) content was then determined by flame atomic absorption spectrometry (FAAS). The method so could be considered as an enrichment process, was achieved to a quantitative feature, when the pH of the solution was adjusted to 4 and the concentrations of iodide and ferroin were about 3.2 x 10(-4) M and 6.25 x 10(-5) M, respectively. The LOD and RSD (n = 7) were obtained 1.0 x 10(-8) M and 2.4%, respectively. It was found that a large number of cations and anions even at high considerably foreign ion/Ag(I) ratios were not interfered. The method was applied satisfactorily to recovery of Ag(I) from different aqueous samples.
Hosseini
Mohammad Saeid
MS
Department of Chemistry, Faculty of Science, Birjand University, Birjand, P.O. Box 79, Iran.
Hashemi-Moghaddam
Hamid
H
Kardan-Moghaddam
Gholamreza
G
D007454:Iodides / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry*; D012834:Silver / Q000032:analysis / Q000302:isolation & purification*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014867:Water