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 internsity is measured at 570nm with excitation at 540nm. A linear calibration graph was obtained over the copper concentration range of 0.05-0.50mg/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.