Cobalt（Ⅱ）ion can catalyze the decolorrization reaction of hydrogan peroxide and m-cresol purple in a pH=10.0 NH3-NH4Cl buffer solution.The kinetic condition was studied,and the apparent activation energy（E′a=51.2...Cobalt（Ⅱ）ion can catalyze the decolorrization reaction of hydrogan peroxide and m-cresol purple in a pH=10.0 NH3-NH4Cl buffer solution.The kinetic condition was studied,and the apparent activation energy（E′a=51.26 KJ/mol.）and apparent rate constant[k′=1.13×10-4(s-1)]were determined.The linear range is 4.0～40 μg/L,and the detection limit for cobalt（Ⅱ）is 6.0×10-10 g/mL.The method was applied to the direct determination of trace Co（Ⅱ）in VB12,Jasmine tea and groundwater samples.展开更多
A novel catalytic spectrophotometric method for determination of trace cobalt has been developed.It was based on the strong catalytic effect of Co(II) on the oxidation of gallic acid by hydrogen peroxide in alkaline m...A novel catalytic spectrophotometric method for determination of trace cobalt has been developed.It was based on the strong catalytic effect of Co(II) on the oxidation of gallic acid by hydrogen peroxide in alkaline medium.The optimum experimental conditions were investigated,the results exhibited that the proposed method had higher sensitivity and good selectivity compared with those reported methods.The calibration graph was linear over the range 2.5×10–3～3.0×10–2ng/mL with a detection limit(3σ) of 6.0×10–4ng/mL.The method had been applied to the determination of cobalt in human hair and water samples with satisfactory results.展开更多
文摘Cobalt（Ⅱ）ion can catalyze the decolorrization reaction of hydrogan peroxide and m-cresol purple in a pH=10.0 NH3-NH4Cl buffer solution.The kinetic condition was studied,and the apparent activation energy（E′a=51.26 KJ/mol.）and apparent rate constant[k′=1.13×10-4(s-1)]were determined.The linear range is 4.0～40 μg/L,and the detection limit for cobalt（Ⅱ）is 6.0×10-10 g/mL.The method was applied to the direct determination of trace Co（Ⅱ）in VB12,Jasmine tea and groundwater samples.
文摘A novel catalytic spectrophotometric method for determination of trace cobalt has been developed.It was based on the strong catalytic effect of Co(II) on the oxidation of gallic acid by hydrogen peroxide in alkaline medium.The optimum experimental conditions were investigated,the results exhibited that the proposed method had higher sensitivity and good selectivity compared with those reported methods.The calibration graph was linear over the range 2.5×10–3～3.0×10–2ng/mL with a detection limit(3σ) of 6.0×10–4ng/mL.The method had been applied to the determination of cobalt in human hair and water samples with satisfactory results.
