Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Ar...Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Arsenazo M itself. The apparent molar absorptivity of the BSA-Arsenazo M complex is 3.21105 Lmol-1cm-1. The linear ranges for protein determination are wide (at least 0-100 mg/mL).展开更多
A catalytic spectrophotometry for the determination of trace amount of vanadium was developed based on its catalytic effect on the oxidation of arsenazo by potassium bichromate in weak acidic medium. The optimized co...A catalytic spectrophotometry for the determination of trace amount of vanadium was developed based on its catalytic effect on the oxidation of arsenazo by potassium bichromate in weak acidic medium. The optimized conditions for determinations are: cK2Cr2O7=3.010-5 molL-1, carsenazo =3.010-5 molL-1, pH=4.0, t=90. The calibration graph is linear for 0.020.2 gml-1, and the detection limit is 0.02 gml-1 V. The apparent active energy of this catalytic reaction is 21.72 kJmol-1. Most foreign ions do not interfere with the determination of vadadium, except for Fe() and Co(), and their interferences could be eliminated by ion exchange. The present method has been used to make the determination of vanadium in human hair, tea, potato and wastewater, and the results were satisfactory.展开更多
In the medium of 0.18～1.08 mol·L^(-1) sulfuric acid, cerium(Ⅳ) has the color-fading effect on DBC-arsenazo. The apparent molar absorptivity of the color-fading reaction is ε _(530 nm)=1.03×10~4 L·mo...In the medium of 0.18～1.08 mol·L^(-1) sulfuric acid, cerium(Ⅳ) has the color-fading effect on DBC-arsenazo. The apparent molar absorptivity of the color-fading reaction is ε _(530 nm)=1.03×10~4 L·mol^(-1)·cm^(-1). Beer′s law is obeyed over the range of 1.20～12.0 μg·ml^(-1) of Ce (Ⅳ) which shows a linear relationship with the decrease in the absorbance of the colored solution. The effect of thirty-six coexisting ions was studied. The method was applied to the determination of the trace amount of cerium in water samples and has the advantage of high accuracy and good selectivity.展开更多
文摘Arsenazo M could bind with bovine serum albumin to form a complex in Clark-Lube buffer at pH 2.3 and room temperature, which gives a maximum absorption peak at 625 nm with a red shift of 75 nm compared with that of Arsenazo M itself. The apparent molar absorptivity of the BSA-Arsenazo M complex is 3.21105 Lmol-1cm-1. The linear ranges for protein determination are wide (at least 0-100 mg/mL).
文摘A catalytic spectrophotometry for the determination of trace amount of vanadium was developed based on its catalytic effect on the oxidation of arsenazo by potassium bichromate in weak acidic medium. The optimized conditions for determinations are: cK2Cr2O7=3.010-5 molL-1, carsenazo =3.010-5 molL-1, pH=4.0, t=90. The calibration graph is linear for 0.020.2 gml-1, and the detection limit is 0.02 gml-1 V. The apparent active energy of this catalytic reaction is 21.72 kJmol-1. Most foreign ions do not interfere with the determination of vadadium, except for Fe() and Co(), and their interferences could be eliminated by ion exchange. The present method has been used to make the determination of vanadium in human hair, tea, potato and wastewater, and the results were satisfactory.
文摘In the medium of 0.18～1.08 mol·L^(-1) sulfuric acid, cerium(Ⅳ) has the color-fading effect on DBC-arsenazo. The apparent molar absorptivity of the color-fading reaction is ε _(530 nm)=1.03×10~4 L·mol^(-1)·cm^(-1). Beer′s law is obeyed over the range of 1.20～12.0 μg·ml^(-1) of Ce (Ⅳ) which shows a linear relationship with the decrease in the absorbance of the colored solution. The effect of thirty-six coexisting ions was studied. The method was applied to the determination of the trace amount of cerium in water samples and has the advantage of high accuracy and good selectivity.
