Fluorescence Spectrometric Determination of Aluminum(III) Ion in Water Using 4-Chloro-2-phenyliminomethylphenol

Abstract

Al(III) ion is usually found in spring water and ground water naturally. It is often found in tap water due to coagulation reagents, such as aluminum sulfate or poly aluminum chloride, used for the water cleaning process. It is also found in teas and kitchen vessels. The toxicity of Al(III) ion in human body has been a topic of interest over the past decades. It can damage various tissue cells in the central nervous system, and it has been suggested that accumulated aluminum in brain tissues is a cause of Alzheimer's disease. Therefore, considerable attention has been paid to the development of the quantitative determination of trace amount of Al(III) ion in water. Several methods have been established to detect the presence of Al(III) ion in water. It has been revealed that the absorption spectroscopic method has relatively low detection sensitivity. However, the fluorescence spectrometric method has been used for the quantitative determination of many organic and inorganic compounds due to its unique high sensitivity. Various organic compounds, such as salicylidene-o-aminophenol, N-salicylidene-2-amino-3-hydroxyflurene, N,N'-oxalylbis(salicylaldehydehydrazone), 2,6-bis[(o-hydroxy)phenyliminomethyl]-1-hydroxybenzene, and other Schiff base ligands, have been identified as useful fluorescent reagents for the quantitative determination of Al(III) in water. In this work, we synthesized a new bidentate Schiff base ligand, 4-chloro-2-phenyliminomethylphenol (Cl-PMP), as shown in Figure 1. Interestingly, Cl-PMP has been found to be useful for the quantitative determination of small amount of Al(III) ion dissolved in tap water, spring water or mineral water.