RT journal article
T1 Determination of silver in seawater by the direct analysis of solvent bars by high resolution continuum source solid sampling graphite furnace atomic absorption spectrometry
A1 González-Álvarez, Rafael J.
A1 Bellido Milla, Dolores
A1 Pinto Ganfornina, Juan José
A1 Moreno Aguilar, Carlos
A2 Química Analítica
AB The direct analysis of solvent bars used for silver micro-extraction from seawater samples by high resolution continuum source solid sampling graphite furnace atomic absorption spectroscopy (HR-CS-SS-GF-AAS) has been achieved. Three successive pyrolysis steps at 290 °C, 700 °C and 1000 °C were applied to ensure the elimination of the fumes released during the calcination of the bar prior to the atomization at 1800 °C. Silver micro-extraction with solvent bars was optimised by applying a multivariate strategy. The concentrations of the extracting agent (tri-isobutylphosphine sulphide), reextracting reagent (sodium thiosulfate) and nitrate were studied by using a central composite design based on the surface response methodology. The optimum values were 0.168 mol L-1, 0.033 mol L-1 and 0.159 mol L-1, respectively. Under these conditions, a stirring rate of 1000 rpm and an extraction time of 20 minutes were optimum. Additionally, the effect of chlorides and humic acids was also studied. The method exhibited a repeatability and reproducibility of 1.54% and 2.68%, respectively, with a limit of detection of 2.52 ng L-1 and a linear range up to 334 ng L-1. For the first time, an ultra-trace element (silver at the ng L-1 level) was pre-concentrated and determined in seawater by using a direct solid analysis-based method, simplifying the sample preparation process and avoiding its manipulation. The method was successfully applied to dissolved silver determination in real seawater samples after the micro-extraction process and was validated by comparison with the reference method of liquid-liquid extraction with APDC/DDDC and ICP-MS determination.
PB ROYAL SOC CHEMISTRY
SN 1364-5544
YR 2018
FD 2018
LK http://hdl.handle.net/10498/30362
UL http://hdl.handle.net/10498/30362
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 12-nov-2026