DETERMINATION OF TRACE ALUMINUM IN NATURAL-WATERS BY FLOW-INJECTION ANALYSIS WITH FLUORESCENT DETECTION OF THE LUMOGALLION COMPLEX

A now-injection analysis method is described for the determination of trace levels of aluminum using fluorescent detection of the Al-lumogal lion complex. The method is very simple, requiring neither iron maskin g agents nor micelle forming compounds to improve sensitivity. The det ection limit is 3.7 nM with linearity to 37 mu M and a relative standa rd deviation at 1.1 mu M of 0.8%. Naturally occurring substances which might be expected to react with aluminum or lumogallion, including ci tric acid, fulvic acid and iron(III), show no interference. The detect ion of all forms of aluminum except polymers is demonstrated, making t he method useful as a speciation procedure for the determination of fr ee and complexed forms of aluminum in acid impacted as well as non-imp acted aquatic systems. Results of analyses of water samples from lakes having a variety of pH values are presented with comparison to result s obtained by GFAAS.