Abstract:

n the aqueous medium at pH 5.0 and in the presence of sodium dodecyl sulfate (SLS), the energy transfer from acridine orange (AO) to eosin Y(EY) enhances the fluorescence of EY, and the addition of nickel (II) makes EY occur fluorescence quenching at 541 nm. The degree of quenching and the content of nickel is linear. A new method for determine trace nickel based on energy transfer was established. The results showed that when the content of nickel is in the range of 0.001 to 0.1 μg/ml, its relationship with the intension of fluorescence quenching (△F) fits to Bill law, and its detection limit is 0.53 ng/ml . For 11 times determination of 1  μg standard nickel (II), the relative standard deviation is 2.4%. To determine the content of nickel in plant samples, the relative error is less than 3%, which meets the requirement of trace analysis.

Key words: acridine orange, eosin Y, energy transfer, fluorescence quenching, nickel