Spectrophotometeric determination of trace amounts of Al3+ ion in water samples after cloud point extraction using quinizarin as a complexing agent

In this study, cloud point extraction was used for the preconcentration of Al3+ ion after the complex formation with 1,4-dihydroxy-9,10-anthraquinone (Quinizarin [QUIN]), and subsequent analysis by spectrophotometeric method, using Triton X-114 as surfactant. The optimal extraction and reaction conditions were studied (i.e., pH = 5.5, 0.1 mM QUIN, Triton X-114 = 0.1 % (w/v)), and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and enrichment factors) were obtained. Linearity was obeyed in the range of 3.33-166.67 ng ml(-1) of Al3+ ion. The detection limit of the method was 2.09 ng ml(-1) for Al3+ ion. The interference effect of some anions and cations was also tested. The method was applied to determine Al3+ ion in water samples.