On-line preconcentration of nickel on activated carbon prior to its determination by vapor generation associated to inductively coupled plasma optical emission spectrometry

Abstract

An on-line nickel preconcentration system implemented with chemical vapor generation associated to inductively coupled plasma optical emission spectrometry (VG-ICP-OES) was studied. Trace amounts of nickel were preconcentrated by sorption on a minicolumn packed with activated carbon at pH 5.0. The analyte retained was removed from the minicolumn with 0.3 mol l À1 hydrochloric acid. After that, volatile species of nickel were generated by merging the acidified sample and sodium tetrahydroborate(III) in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the inlet tube of the inductively coupled plasma torch. For the preconcentration procedure, an enrichment factor of 36-fold for a sample volume of 25 ml was obtained. The detection limit (DL) obtained was 0.06 mg l À1 . The precision (RSD) for ten replicate determinations at a level of 0.5 mg l À1 was 4.0%. Potential interfering effects on the Ni signal were examined.

A New Thioamide Derivative for Separation and Preconcentration of Multi Elements in Aquatic Environment by Cloud Point Extraction

“…Due to the low concentration of these metals in the environmental and biological samples and interfering effects, a preconcentration/separation technique is generally necessary prior to the determination. For this purpose, various analytical procedures have been used, such as adsorption on activated carbon [3,4] co-precipitation [5,6] column extraction [7,8] ion-selective electrode [9,10] liquid-liquid extraction (LLE) [11] and cloud-point extraction (CPE) [12][13][14][15][16][17][18][19][20][21][22].…”

Thin film hydride generation: determination of ultra-trace copper by flow injection in situ hydride trapping graphite furnace AAS

“…Following the report of detection of a volatile species of copper generated by merging its acidified sample solution with sodium tetrahydroborate, 2 a significant effort has arisen to use the acid-tetrahydroborate system to form (volatile) species of transition and noble elements (Ag, Au, Fe, Cr, Co, Cu, Ni, Os, Pd, Rd, Rh, Tl and Zn) which can be phase separated and transported to detectors by a carrier gas. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] Because there is little information on either the identity of the species generated, or the reaction mechanism, such studies remain largely in a state of debate due to the complex nature of the reaction and the rather low generation efficiency. Several studies suggest that the metal ions are reduced to unstable reaction intermediates by tetrahydroborate, ultimately p roducing free atoms, hydrido-metal complexes and nanoparticles.…”

Synthesis of Bis(amino alcohol)oxalamides and Their Usage for the Preconcentration of Trace Metals by Cloud Point Extraction

“…1,2 Due to the low concentration of trace elements and interfering effects of the major components of the initial sample matrix, a preconcentration/separation technique is generally necessary prior to atomic absorption spectrometry. For this purpose, various analytical methods have been used, such as adsorption on activated carbon, 3,4 co-precipitation, 5,6 column extraction, 7,8 ion-selective electrode 9,10 liquid-liquid extraction (LLE), 11 and cloud-point extraction (CPE). [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Cloud-point extraction (CPE), employed in analytical chemistry to separate and preconcentrate organic compounds and metal ions, has been well reviewed.…”