Coprecipitation with lanthanum phosphate as a technique for separation and preconcentration of iron(III) and lead

Abstract

The usefulness of coprecipitation with lanthanum phosphate for separation and preconcentration of some heavy metals has been investigated. Although lanthanum phosphate coprecipitates iron(III) and lead quantitatively at pH 2.3, iron(II) can barely be collected at this pH. This coprecipitation technique was applicable to the separation and preconcentration of iron(III) before inductively coupled plasma atomic-emission spectrometric (ICP-AES) determination; the recoveries of iron(III) and iron(II) from spiked water samples were 103-105% and 0.2-0.7%, respectively. The coprecipitation was also useful for separation of 20 microg lead from 100 mL of an aqueous solution that also contained 1-100 mg iron. Coprecipitation of iron was substantially suppressed by addition of ascorbic acid, which enabled recovery of 97-103% of lead added to the solution, bringing the recovery to within 1.6-5.0% of the relative standard deviations. Lanthanum phosphate can also coprecipitate cadmium and indium quantitatively, although chromium(III), cobalt, and nickel and large amounts of sodium, potassium, magnesium, and calcium are barely coprecipitated at pH approximately/= 3.

Use of Escherichia coli Immobilized on Amberlite XAD-4 as a Solid-Phase Extractor for Metal Preconcentration and Determination by Atomic Absorption Spectrometry

“…Various separation and preconcentration techniques have been used for trace metals, such as solvent extraction, [1][2][3] coprecipitation, [4][5][6] electrodeposition, 7 ion-exchange, [8][9][10] cloud point extraction technique 11 and solid-phase extraction 12 (SPE), adsorption on activated carbon, 13 on dithixone-anchored poly(EGDMA-HEMA) microbeads, 14 on Amberlite resins 15 and on sepiolite. 16 The preconcentration procedures employing a solid phase and applied to atomic spectrometry present some advantageous characteristics, such as simplicity, column applicability and a higher preconcentration factor.…”

Polyelectrolyte Modified Silica Gel Micro-Column Solid Phase Extraction for the Determination of Silver in Environmental Water Samples by Flame Atomic Absorption Spectrometry

“…Preconcentration is a very important issue for improvement of sensitivity, and separation is an efficient technique to reduce the interference of sample matrix [5]. Various separation-preconcentration procedures have been used for this purpose, including liquid-liquid extraction [6], solid phase extraction [7][8][9], ion exchange techniques [10], coprecipitation [11] and cloud point extraction [12][13].…”

Use of Yttrium Phosphate as a Coprecipitant for Separation/Concentration of Lanthanoids

“…We have studied the coprecipitation of elements with metal phosphates, and have also applied the coprecipitation method to the separation/concentration of elements, including Pb, [14][15][16][17][18][19][20][21] Sn(IV), 22 In, 23 Cr(III), 24 Fe(III), 15,20,21 Bi, 15 and Cd, 25 for their atomic spectroscopic determination.…”