Spectrophotometric Determination of Copper(II) in Water based on Fluorescein Diacetate

Abstract Two novel methods for spectrophotometric determination of Cu 2+ ion using synthesized and characterized furfuraldehyde fluorescein diacetate hydrazone ( FFDH ) and furfuraldehyde fluorescein hydrazone ( FFH ) have been proposed. Addition of Cu 2+ to FFDH and FFH solutions results in a rapid color change from colorless to dark yellow. Experimental results show that FFH and FFDH both can provide a rapid, selective and sensitive response to Cu 2+ within a linear dynamic range of 7–33 µM and the detection limits of 1.1 × 10 –7 and 7 × 10 –8 M, respectively. Apparently, the detection limit of FFDH is lower than that of FFH, which indicates that FFDH forms a more stable complex with Cu 2+ . In addition, the detection of Cu 2+ in water samples was also studied; as a result, the developed FFDH was found to be more applicable than FFH for spectrophotometric determination of Cu 2+ in environmental water samples. Particularly, as a lipid chemical compound, FFDH may be transported across the cell membrane to detect Cu 2+ in vivo. It is of great significance in many fields, such as biology, biochemistry, medicine and environment.