An AI^3＋ sensor based on the membrane of acetyl cellulose containing nano γ-Al2O3 crystals was studied. In the buffer solution of 0.5 mol/L CH3COOH-CH3COONa （pH=5.0）, the sensor responds to AI^3＋ in a linear range from 1.00×10^-5 to 1.00x10-^2 mol/L. A near-Nernstian response was obtained and the regression equation was E （mv） = -161.4-26.54 Ig [AI^3＋] with a detection limit of 7.90x10^-6 mol/L. More than 14 different ions as the considered interferences were tested and the relevant selectivity coefficients were determined using the separate solution method （SSM）. The sensor possesses many advantages including short conditioning time, fast response, and, especially, very good selectivity over a wide variety of other co-existing ions. The sample analysis on the aluminium migration amount from aluminium utensils to the solution was determined by this sensor. The analytical results were agreed with that of inductively coupled plasma-atomic emission spectroscopy（ICP-RES）.
MA Chuan-li HE Li-jun, TIAN Li-fang WANG Chun-ming
In this paper, TiO2 loaded on activated carbon fibers （ACF） was prepared by a coating treatment, followed by calcination at different temperatures in air atmosphere. The photocatalyst developed was characterized by SEM, XRD, XPS and UV-Vis adsorption spectroscopy. It was observed from SEM images that TiO2 loaded on ACF was in the form of small clusters with nanometer size. As confirmed by XRD and XPS determinations, the crystalline pattern of immobilized TiO2 was still anatase-form after calcination, and the micrographic structure and surface properties of ACF have not been damaged by the deposition process and calcination at different temperatures. Photocatalytic degradation of methylene blue （MB） in aqueous .solution was investigated using TiOE/ACF as photocatalyst. The comparison of photolysis, absorption and photocatalysis was carded out. The results indicated that the photocatalysis process of combined photocatalyst showed much higher degradation rate than that of photolysis and absorption processes. In addition, the possibility of cyclic usage of the photocatalyst was also confirmed.
