Preconcentration of trace aluminum from environmental water samples with 5'-chloro-5-dodecyl-2,4,2'-trihydroxyazobenzene impregnated macroporous resin.

5'-Chloro-5-dodecyl-2,4,2'-trihydroxyazobenzene (CDTA) impregnated XAD-4 resin (CDTA resin) was prepared, and applied to the preconcentration of trace aluminum from environmental water samples with satisfactory results. Aluminum was measured by flow-injection analysis (FIA) with fluorescence detection by using lumogallion after the preconcentration of aluminum with CDTA resin. Fe3+ and other coexisting substances had no interference on the determination of aluminum by the present method. Chemical speciation of trace aluminum in environmental water was carried out by using the CDTA resin after the separation of aluminum species with ionic exchangers without changing the pH. About 50% of water-soluble aluminum in Lake Biwa was found to be aluminum organic species (anion species).