A new catalytic spectrophotometric method was developed for the determination of trace amount of Se（Ⅳ） in microemulsion medium. The method is based on the catalytic effect of traces of Se（Ⅳ） on the oxidation of ...A new catalytic spectrophotometric method was developed for the determination of trace amount of Se（Ⅳ） in microemulsion medium. The method is based on the catalytic effect of traces of Se（Ⅳ） on the oxidation of 2＇,4＇-dichlorophenylfluomne （p-CPF） by potassium bromate with HNO3 as an activator in the presence of nonionic microemulsion medium. Under optimum conditions, the calibration graph is linear in the range of 0.4-15 μg·L^-1 of Se（Ⅳ） at 480 nm. The detection limit achieved is 9.86 × 10^-10μg·L^-1. Samples were dissolved and the obtained trace Se（Ⅳ） was separated and enriched by sulphydryl dextrane gel （SDG）. The method has been applied for determination of trace selenium with satisfactory results.展开更多
The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate ...The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate （（NH4）2S2O8） with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au（Ⅲ） at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel （SDG） as a solid-phase extractant has been developed for the preconcentration and separation of Au（Ⅲ） ions. The method has been applied to the determination of trace gold with satisfactory results.展开更多
The synthesis and analytical properties of 4,4'-bis(antipyrinyl-4-diazoamino)biphenyl (BAPDAB) were described for the first time. A catalytic kinetic method for thedetermination of silver was proposed. In the pres...The synthesis and analytical properties of 4,4'-bis(antipyrinyl-4-diazoamino)biphenyl (BAPDAB) were described for the first time. A catalytic kinetic method for thedetermination of silver was proposed. In the presence of Triton X-100 as a solubilizing agent and2,2'-dipyridyl as an activator, silver has a very strong catalytic effect on oxidative decolorationof BAPDAB by persulfate in acetic acid medium. The reaction was followed spectrophotometrically bymeasuring the decrease of absorbance of BAPDAB at 478 nm and 50 ℃. The calibration graphs are ofgood linearity in the range of 8.0 * 10^(-10)-1.0 * 10^(-6) mol/L by a fixed time method. The limitof detection is down to 5.0 * 10^(-10) mol/L. The catalytic reaction is pseudo-first-order withrespect to silver, which in real samples was determined with satisfactory results.展开更多
文摘A new catalytic spectrophotometric method was developed for the determination of trace amount of Se（Ⅳ） in microemulsion medium. The method is based on the catalytic effect of traces of Se（Ⅳ） on the oxidation of 2＇,4＇-dichlorophenylfluomne （p-CPF） by potassium bromate with HNO3 as an activator in the presence of nonionic microemulsion medium. Under optimum conditions, the calibration graph is linear in the range of 0.4-15 μg·L^-1 of Se（Ⅳ） at 480 nm. The detection limit achieved is 9.86 × 10^-10μg·L^-1. Samples were dissolved and the obtained trace Se（Ⅳ） was separated and enriched by sulphydryl dextrane gel （SDG）. The method has been applied for determination of trace selenium with satisfactory results.
文摘The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate （（NH4）2S2O8） with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au（Ⅲ） at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel （SDG） as a solid-phase extractant has been developed for the preconcentration and separation of Au（Ⅲ） ions. The method has been applied to the determination of trace gold with satisfactory results.
文摘The synthesis and analytical properties of 4,4'-bis(antipyrinyl-4-diazoamino)biphenyl (BAPDAB) were described for the first time. A catalytic kinetic method for thedetermination of silver was proposed. In the presence of Triton X-100 as a solubilizing agent and2,2'-dipyridyl as an activator, silver has a very strong catalytic effect on oxidative decolorationof BAPDAB by persulfate in acetic acid medium. The reaction was followed spectrophotometrically bymeasuring the decrease of absorbance of BAPDAB at 478 nm and 50 ℃. The calibration graphs are ofgood linearity in the range of 8.0 * 10^(-10)-1.0 * 10^(-6) mol/L by a fixed time method. The limitof detection is down to 5.0 * 10^(-10) mol/L. The catalytic reaction is pseudo-first-order withrespect to silver, which in real samples was determined with satisfactory results.
