Abstract
Pre-concentration methods of aluminum for flame atomic absorption spectrophotometry (FAAS) by solvent extraction and solid-phase extraction using 8-quinolinol (8-HQ) derivatives as a chelating reagent were investigated, where an organic solvent extracted or dissolved the aluminum with the chelating reagent was directly introduced into FAAS. In the case of the solid-phase extraction of aluminum with 0.29 g of a powdered solid of 8-HQ using 100 ml of sample water in the presence of 0.1 mol dm−3 sodium carbonate buffer at pH 9.0 for 90 min stirring, the highest apparent enrichment factor of the aluminum ion was 28, when the powdered solid 8-HQ extracted the aluminum was dissolved in 1 ml of nitrobenzene (NB). In the case of solvent extraction, the highest pre-concentration of the aluminum by the solvent extraction of 1000 ml of the sample water in the presence of 0.1 mol dm−3 sodium carbonate buffer at pH 9.0 with 2 mol dm−3 8-HQ in 3 ml NB for 70 min stirring was achieved. The enrichment factor and the detection limit (3 σ) of the aluminum were 514 and 2.7 ng ml−1, respectively. The relative standard deviation for FAAS signals in this method was 8.5% (n = 8) for 10 ng ml−1 aluminum. The high pre-concentration method of solvent extraction was applied to the determination of aluminum in river water and tap water, resulting in 10.9, 4.5, and 9.5 ng ml−1 for tap water and two river-water samples, respectively.
