Effect of pH on the characteristics of potassium permanganate-luminol CL reaction in the presence of trace aluminum(III) and its analytical application.
At pHs> or =11.45, trace Al was found to enhance the CL from luminol-KMnO(4) system. However, at pHs< or =10.42, it was found to inhibit strongly the CL from luminol-KMnO(4) system. The effect of pH, luminol and potassium permanganate concentrations on the kinetic characteristics of CL system was investigated in the presence of trace Al. On this basis, a flow injection inhibition chemiluminescence method was established for the determination of trace Al in this study. Under optimized conditions, the CL decreased linearly with Al(III) concentration in the range of 8-500microg L(-1) and the detection limit (3sigma) of 2microg L(-1). The relative standard deviation (R.S.D.) is 3.6% for 100microg L(-1) Al(III) (n=11). The method has been applied to the determination of trace Al in real water samples with satisfactory results without the pretreatment of samples. The results given by the proposed method are in good agreement with those given by ICP-AES detection method.
Pan
Jin
J
College of Chemistry and Chemical Engineering, The Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments, Southwest University, Ministry of Education, Chongqing 400715, China.
Huang
Yuming
Y
Shu
Weiqun
W
Cao
Jia
J