FLUORESCENCE ENHANCEMENT OF Al3+– SODIUM MORIN–5–SULFONATE COMPLEX BY IMIDAZOLIUM IONIC LIQUID AND ITS APPLICATION IN DETERMINATION OF Al3+ IONS IN AN AQUEOUS SOLUTION

Abstract

This study describes the preparation of sodium morin–5–sulfonate (NaMSA) as a new reagent for the determination of aluminium(III) (Al 3+ ) ions based on the formation of a ternary complex. The complex consists of Al 3+ , NaMSA, and 1–Butyl–3–methylimidazolium hexafluorophosphate (BMIM–PF 6 ). It was found that this method was sensitive compared to the binary complex of Al 3+ and NaMSA. The ternary complex was excited at 420 nm, and the fluorescence signal was measured at 518 nm. Maximum fluorescence signal produced at pH 5.0 (acetic acid–acetate buffer), with 0.02% v/v BMIM–PF 6 and 1.0 × 10 -4 molL -1 of NaMSA. The calibration graph in linear up to 10 mgL -1 with the calculated detection limit of 0.017 mgL -1 . Effect of foreign ions towards the ternary complex was also studied. Finally, the method was applied in the determination of Al 3+ ions in water samples, and satisfactory results were obtained.