Extraction-Fluorimetric Determination of Low Levels of Copper by 1,7- Diaza-15-Crown-5 and Rose Bengal

A simple and sensitive extraction-fluorimetric method for the determination of copper is reported. The 1,7-diaza-15-crown-5-copper-rose Bengal (DA15C5-Cu-RB) ternary complex is quantitatively extracted into chloroform, diluted with ammoniacal acetone and its fluorescence intensity is measured at 570 nm with excitation at 540 nm. A linear calibration graph was obtained over the copper concentration range of 0.05-0.50 mg/mL. The relative standard deviation for 0.35 mg/mL copper is 3.9%. The interfering effect of a large number of diverse ions on the determination of copper was studied. The method was applied to the determination of copper in tap water.