Supramolecular solvent based liquid-liquid microextraction of aluminum from water and hair samples prior to UV-visible spectrophotometric detection

A new method for the microextraction of aluminum from water and hair samples has been developed using a supramolecular solvent (undecanol-tetrahydrofuran) prior to UV-visible spectrophotometric determination. 8-Hydroxyquinoline was used as chelating agent which forms a chelate with Al(III) at pH 8.0. The Al(III)-8-hydroxyquinoline chelate was quantitatively extracted into the supramolecular solvent (Ss) phase. The molar absorptivity calculated for the complex was 1.8 x 10(3) L mol cm(-1) at 380 nm. Factors effecting extraction efficiency of the method including pH, amount of chelating agent, sample volume, type and volume of supramolecular solvent (Ss) and matrix effect were optimized. A pre-concentration factor of 30 was achieved with a limit of quantification of 0.47 mu g L-1 with relative standard deviation of 0.3%. The accuracy of the developed method was evaluated by the analysis of the certified reference materials (SPS WW2 waste water, TMDA-53.3 fortified water and NCS ZC81002B human hair) and by addition-recovery studies for water and hair samples.