Determination of silver in seawater by the direct analysis of solvent bars by high resolution continuum source solid sampling graphite furnace atomic absorption spectrometry
| Autor: | Rafael Jesús González-Álvarez, Carlos Moreno, Juan J. Pinto, Dolores Bellido-Milla |
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| Rok vydání: | 2018 |
| Předmět: |
Detection limit
Materials science Central composite design 010401 analytical chemistry Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Analytical Chemistry law.invention Linear range law Reagent Calcination Seawater Sample preparation 0210 nano-technology Graphite furnace atomic absorption Spectroscopy |
| Zdroj: | Journal of Analytical Atomic Spectrometry. 33:1925-1931 |
| ISSN: | 1364-5544 0267-9477 |
| DOI: | 10.1039/c8ja00243f |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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