StudyontheDirectDeterminationofTraceElementsinBiologicalandEnvironmentalSamplesandKinetics Of Oxidation Of Transition Metals In A Higher Oxidation State By Spectrophotometry And Theoretical Study Of Chemical Oscillating System Using Potential Method

With XanthanGum and Carbopol 940 as dispersant and NH4H2PO4 as chemical modifier, trace cadmium and lead of solid samples were directly determined by graphite furnace atomic absorption spectrometry(GFAAS) and their pyrolysis temperature can be reached 1000@ and 1100@ respectively. The apparent activation energy of atomizing was proposed firstly, the modifier efficiency and the mechanism of atomizing were reveled satisfactory. The new method of slurry sampling for direct analysis of trace cadmium and lead of solid materials by GFAAS was established and it can successfully be applied to analyze them in environmental and herbal medicine and biological samples. It has provided good analytical results with some advantages over conventional procedures:(i) simplification of sample pre-treatment, diminishing the turnaround time and operational work, (ii) less risks for sample contamination,(ii) minimization of analyte losses caused either by the pre-treatment operations or by the incomplete release of the analyte from the solid matrix. We primarily study the relation of accumulative change of the air of the metal gas solvent in closed cabin and the effect on people. The kinetics of oxidation of ethylene glycol monomethyl ether and malic acid etc by diperiodatonickelate(IV) and ditelluratocuprate(III) have been studied spectrophotometrically. A mechanism of reaction involving a pre-equilibrium is proposed. We primarily reported the experimental investigations of the bromate oscillator using glycerol and mannitol etc with acetone as the mixed organic substrates. The empirical equations of the induction period and oscillating period with the concentrations of the reactants and temperature were obtained. The oscillating characteristic and possible oscillation mechanisms were analyzed. We proposed the synthesize of high absorbance water resin by ultrasonic for the first time, the particle size is very small and the rate of absorption water was swiftness. The kinetics of the cure reaction for systems of bisphenol-s epoxy resin with 4,4'-diaminodiphenyl ether as a curing agent were investigated with a differential scanning calorimetry. Autocatalytic mechanism for curing reaction was proposed.