Silica gel modified with lumogallion for aluminum determination by spectroscopic methods.

Simple, easy to use and selective method of Al(III) sorption-spectroscopic (SS) determination was proposed. For this purpose, silica modified with tridecyloctadecylammonium chloride(SGII) using adsorption technique and glass slide modified with thin silica-poly(dimethyldiallyl-ammonium chloride) (SGI) composite film obtained by sol-gel technique were worked out. It was shown that lumogallion (LG) easily absorbs on SGI and SGII. Obtained sorbents SGIII and SGIV, respectively, were used for aluminum(III) determination by diffuse reflectance and spectrophotometric methods. The ranges of determination were (mg L(-1)): (0.08-0.54), s(r)< or =0.13, n=4 for SGIII and (0.05-2.0), s(r)< or =0.11, n=4 for SGIV. The detection limits (blank+3sigma) for aluminum were 70 and 30 microg L(-1) using SGIII and SGIV, respectively, where sigma is the standard deviation of blank estimation. The accuracy of the developed spectrophotometric method was examined by the determination of standard addition of aluminum in alcohol-free beverages. The relative error did not exceed 9%. SGIII can be regenerated by 0.05M EDTANa(2)H(2) solution and reused. SGIV was shown to be perspective for determination of aluminum in solution in the range of 0.01-0.13 mg L(-1) by solid phase luminescent technique.