ABSTRACT
A new catalytic spectrophotometric method is described for the determination of trace amounts of Al(III). The methods based on catalytic action of Al(III) on the oxidation of indigo carmine (IC) by ammonium persulfate in hexamethylene tetramine-hydrochloric acid ((CH2)6N4-HCl) buffer medium (pH 5.4) and in the presence of surfactant-TritonX-100. The effects of some factors on the reaction speed were investigated. Aluminium concentration is linear for 0-1.2x10(-7) g/ml in this method. The detection limit of the proposed method is 1.96x10(-8) g/ml. Most of the foreign ions except for Cu(II), Fe(III) do not interfere with the determination, and the interference of Cu(II) and Fe(III) in this method can be removed by extraction with sodium diethyldithiocarbamate-carbon tetrachloride (DDTC-CCl4). This system is a quasi-zero-order reaction for Al(III), but it is a quasi-first-order reaction for IC. The apparent rate constant is 2.62x10(-5) s-1 and the apparent activation energy is 6.60 kJ/mol in the system. The proposed method was applied to the determination of trace aluminium(III) in real samples with satisfactory results.
Subject(s)
Aluminum/analysis , Indigo Carmine/chemistry , Trace Elements/analysis , Calibration , Catalysis , Humans , Indicators and Reagents/chemistry , Oxidants/chemistry , Oxidation-Reduction , Spectrophotometry, Ultraviolet , Surface-Active Agents/chemistry , Temperature , Time FactorsABSTRACT
Based on the newest papers about nano-TiO2, the mechanisms of photocatalysis, ways of improving photocatalytic performance, and influencing factors of environment are discussed in this article. And the progresses in the study on some novel catalysis-enhanced or catalysis-assisted technologies such as infrared treatment, electric field effect, microwave effect and ultrasonic effect are introduced. Finally, the applications to waste water treatment, air refreshment in limited space and specially functional materials preparation in the last two years are reviewed.