Preconcentration and separation of Cd(II), Co(II), Cu(II), Ni(II), and Pb(II) in environmental samples on cellulose nitrate membrane filter prior to their flame atomic absorption spectroscopy determinations

Abstract

ABSTRACT A new and sensitive enrichment membrane filtration method was applied for the preconcentration and separation of trace amounts of Cd(II), Co(II), Cu(II), Ni(II), and Pb(II) ions from environmental (water and food) samples prior to their flame atomic absorption spectrometric (FAAS) determinations. The method was based on the collection of analyte ions as quinalizarin complexes on cellulose nitrate membrane filter and then eluted using nitric acid. The concentration levels of Cd(II), Co(II), Cu(II), Ni(II), and Pb(II) ions in the final solutions were determined by FAAS. Various analytical parameters which affect the collection and determination of metal ions including pH, amounts of quinalizarin, sample volume, type and size of the membrane filter, flow rates and matrix effects were investigated. The analyte ions recovery values were measured and found to be in the range of 95–101%. The relative standard deviation (RSD%) was measured to determine the precision of the proposed approach and was found to be ≤5.0%. The detection limits for the proposed method were in the range of 0.1–0.7 μg L−1. The preconcentration factors were 100 and 125 for (Cd(II), Co(II), Cu(II) and Ni(II)) and Pb(II), respectively. The validation of the proposed method was verified by the analysis of certified reference materials. Satisfactory results for separation and preconcentration trace levels of the analyte ions in water and food samples.