Determination of Heavy Metals at Sub-ppm Levels in Seawater and Dialysis Solutions by FA AS after Tetrakis(pyridine)-nickel(II)bis(thiocyanate) Coprecipitation

Abstract

A coprecipitation method has been developed for the determination of Cr(III), Mn(II), Fe(III), Co(II), Cu(II), Cd(II) and Pb(II) ions in aqueous samples by flame atomic absorption spectrometry (FAAS) with the combination of pyridine, nickel(II) as a carrier element and potassium thiocyanate as an auxiliary complexing agent. The obtained coprecipitates were dissolved with nitric acid and measured by FAAS. The coprecipitation conditions, such as the effect of the pH, amounts of nickel, pyridine and potassium thiocyanate, sample volume, and the standing time of the precipitate formation were examined in detail. It was found that the metal ions studied were quantitatively coprecipitated with tetrakis(pyridine)-nickel(II)bis(thiocyanate) precipitate (TP-Ni-BT) in the pH range of 9.0 -10.5. The reliability of the results was evaluated by recovery tests, using synthetic seawater solutions spiked with the analyte metal ions. The obtained recoveries ranged from 96 to 101% for all of the metal ions investigated. The proposed method was validated by analyses of two certified reference materials (NIST SRM 2711 Montana soil and HPS Certified Waste Water Trace Metals Lot #D532205). It was also successfully applied to seawater and dialysis solution samples. The detection limits (n = 25, 3s) were in the range of 0.01 -2.44 mg l -1 for the studied elements and the relative standard deviations were £6%, which indicated that this method could fully satisfy the requiremets for analysis of such samples as seawater and dialysis solution having high salt contents.

Cloud Point Extraction as a Simple Preparation for Trace Amount of Aluminium by New Ligand 2-(3- indolyl) - 4,5 di Phenyl Imidazole(IDPI), after Determination by Flame Atomic Absorption Spectrometry in Real Samples

“…Preconcentration factor of developed method is generally more than small the other study. The detection limits of method are comparable level with the works in literature including cloud point extraction, solid-phase extraction and coprecipitation [41][42][43][44]. Simultaneous separation and preconcentration of Aluminium is one of the important advantages.…”

Bioactivity and mineral contents of wild-grown edible Morchella conica in the Mediterranean Region

“…All conditions of analysis parameters of each element were performed with recommended conditions of the manufacturer (Sahin et al 2008).…”

Column solid-phase extraction of nickel and silver in environmental samples prior to their flame atomic absorption spectrometric determinations

“…Two limitations in these techniques are lower levels of analyte ions than the quantitation limits of the technique and the interferic effects of the main components of the samples [14][15][16][17]. Cloud point extraction [18][19][20], membrane filtration [21,22], solvent extraction [23,24], coprecipitation [25,26], electrodeposition [27,28] are widely used enrichment and separation techniques for heavy metal ions at trace levels in the various samples which contains high saline including sea water, urine, etc. Solid-phase extraction has an important place on the enrichment-separation studies for heavy metal ions because of its simplicity [29][30][31][32][33][34].…”