Contact glow discharge electrolysis (CGDE) of two dyes, weak acid brilliant red B and weak acid flavine G, was investigated under different concentrations, temperature and mediums. From the variation of their concentration with thereactiontime,itwasdemonstratedthattheoxidation wouldbeafirst-orderreaction.OnthebaselineofUVspectra of solution in the degradation process, we deduced that two dyes underwent the oxidative degradation in CGDE. The rate constants, relevant coefficients and the decolorization degree were displayed under different conditions.

An analytical method for the determination of glutamic acid by the sequential perturbation caused by different amounts of glutamic acid on the oscillating chemical system involving the Cu(II)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium is proposed. The method relies on the linear relationship between the changes in the oscillation amplitude of the chemical system and the concentration of glutamic acid. The reaction is implemented in a continuous-flow stirred-tank reactor, and changes in the oscillation amplitude on each perturbation are proportional to the glutamic acid concentration. The use of the analyte pulse perturbation (APP) technique permits sequential determinations on the same oscillating system owing to the expeditiousness with which the steady state is regained after each perturbation. The dynamic range lies between 2.5

A novel and convenient method with good selectivity and high sensitivity for the determination of hydroquinone (HQ) based on the Belousov-Zhabotinskii (B-Z) oscillating chemical reaction has been presented. The optimum condition for the determination has also been investigated. In the B-Z reaction system, when the sample was injected, the change of the amplitude is linearly proportional to the logarithm of the concentration of HQ in the range 1.0

A highly sensitive catalytic quenching spectrofluorimetric method was described for the determination of V(V) based on its catalytic effect on the oxidation of 1,8-diaminonaphthalene by potassium bromate with Tiron as an activator in weakly acidicmediumandthereactionmechanismwasinvestigated.Thereactionwasfollowedspectrofluorimetricallybymeasuring the fluorescence intensity of 1,8-diaminonathphlene (DAN) (λex=356nm,λem=439nm)at a fixed time of 5min from initiation of the reaction. Under the optimum conditions, vanadium(V) can be determined in the range 0.05-50.0ng ml-1 with a S.D.=0.024 for 15 times measurements. The detection limit of the method was down to 0.0088ng ml-1 and the catalytic reaction activation energy was found to be 43.92kJmol-1. The proposed method was tested for the determination of vanadium(V)inriceandnaturalwatersamples.©2002 Elsevier Science B.V.Allrights reserved.

In this work, a newly synthesized ligand, trisalicylicamido triethylamine, acts as a specific reagent for enhancing the fluorescence intensity of Eu III complex with thenoyltrifluoroacetone. The spectrofluorimetric determination of trace amounts of EuIII based on the above system was carried out and its luminescence mechanism was studied. The excitation and emission wavelengths are 348.9 nm and 613.4 nm, respectively. The fluorescence intensities vary linearly with the III 27 concentration of Eu in the range 7.598

An effective spectrophotometric determination of palladium with 1-(2-pyridylazo)-2-naphthol (PAN) using molten naphthalene as a diluent has been studied. A green complex of palladium with PAN is formed at 90

Some common inorganic and organic anions were separated by high-performance ion chromatography coupled with indirect photometric detection and 1,2-dihydroxybenzene-3,5-disulfonate and sodium sulfosalicylate, respectively, as single-column single-component eluents. In respect of detection sensitivity, eluent concentration, eluent acidity and chromato-graphic separation efficiency, 1,2-dihydroxybenzene-3,5-disulfonate or sodium ulfosalicylate were excellent ultraviolet absorbers, capable of completely resolving many common inorganic and organic anions.