A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenaz...A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenazine. The optimal conditions for laccase in organic media areT=55°C, pH=6.5, 1.0×10?2mol/L OPDA, 1.25 mL ethanol, 1.25 mL 1,4-dioxane and 1.25 mL acetone. The linear range of the method proposed in ethanol, 1,4-dioxane and acetone media were 0.44–19.33, 0.11–20.85, 0.38–21.05 U with the detection limit of 0.088, 0.022, 0.076 U, respectively. The proposed method has been applied to the analysis of laccase activity of real samples with more accurate and sensitive than that of the previous method reported.展开更多
A simple and highly sensitive method for the determination of triamcinolone acetonide in pharmaceutical formulations is presented. The approach is based on the fluorescence of production of triamcinolone acetonide oxi...A simple and highly sensitive method for the determination of triamcinolone acetonide in pharmaceutical formulations is presented. The approach is based on the fluorescence of production of triamcinolone acetonide oxidized by concentrated sulfuric acid. The effect of H2SO4, β-cyclodextrin (β-CD), solvent and cetyltrimethylammonium bromide (CTMAB) were discussed. And two analytical systems were established. One is CTMAB system, the linear range is 0–4.6×10?6 mol/L, and the detection limit is 3.59×10?8 mol/L. The other is β-CD and ethanol system, the linear range is 0–2.3×10?6 mol/L and the detection limit is 1.91×10?8 mol/L. The selectivity of analysis, the analytical figures of optimization, and the accuracy of the method are demonstrated with the determination of triamcinolone acetonide in pharmaceutical preparations. Key words triamcinolone acetonide - fluorimetry - CTMAB - β-cyclodextrin - pharmaceutical analysis CLC number O 657.39 Foundation item: Supported by the National Natural Science Foundation of China (20275028)Biography: Pan Zu-ting (1945-), male, Professor, research direction: analytical chemistry.展开更多
Ce(Ⅲ)-ALC-F complex can react with hsDNA to form an electrochemically non-active supermolecular complex Ce(Ⅲ)-ALC-F-DNA in the buffer solution of (CH2)6N4(pH=4.9), which results in the decrease of the peak current o...Ce(Ⅲ)-ALC-F complex can react with hsDNA to form an electrochemically non-active supermolecular complex Ce(Ⅲ)-ALC-F-DNA in the buffer solution of (CH2)6N4(pH=4.9), which results in the decrease of the peak current of Ce(Ⅲ)-ALC-F. This method can be applied to determine DNA concentration. In addition, by using fluorimetric and UV-spectrophotometric methods with studies of denatured DNA and the effect of NaCl solution , it is also found that the binding mode is intercalation.展开更多
A new spectrofluorimetric method for determination of trace terbium based on its reaction with 2.6-his-(1'-phenyl-3'-methyl-5'- pyridinediacyl (H_2PMBPP) and N- cetylpyridium bromide (CPB). at an apparent ...A new spectrofluorimetric method for determination of trace terbium based on its reaction with 2.6-his-(1'-phenyl-3'-methyl-5'- pyridinediacyl (H_2PMBPP) and N- cetylpyridium bromide (CPB). at an apparent pH=5.0 provided by a hexamethylenetetramine (5% w/w)-hydrochloric acid buffer,is propesed. The calibration graph is linear in the ran ge from展开更多
The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has bee...The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.展开更多
Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ter...Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5~100μg/mL.展开更多
文摘A novel fluorimetric method for determination of laccase activity in organic solvents is proposed, based on the oxidation ofo-phenylenediamine (1,2-diaminobenzene, OPDA) catalyzed by laccase yielding 2,3-diaminophenazine. The optimal conditions for laccase in organic media areT=55°C, pH=6.5, 1.0×10?2mol/L OPDA, 1.25 mL ethanol, 1.25 mL 1,4-dioxane and 1.25 mL acetone. The linear range of the method proposed in ethanol, 1,4-dioxane and acetone media were 0.44–19.33, 0.11–20.85, 0.38–21.05 U with the detection limit of 0.088, 0.022, 0.076 U, respectively. The proposed method has been applied to the analysis of laccase activity of real samples with more accurate and sensitive than that of the previous method reported.
文摘A simple and highly sensitive method for the determination of triamcinolone acetonide in pharmaceutical formulations is presented. The approach is based on the fluorescence of production of triamcinolone acetonide oxidized by concentrated sulfuric acid. The effect of H2SO4, β-cyclodextrin (β-CD), solvent and cetyltrimethylammonium bromide (CTMAB) were discussed. And two analytical systems were established. One is CTMAB system, the linear range is 0–4.6×10?6 mol/L, and the detection limit is 3.59×10?8 mol/L. The other is β-CD and ethanol system, the linear range is 0–2.3×10?6 mol/L and the detection limit is 1.91×10?8 mol/L. The selectivity of analysis, the analytical figures of optimization, and the accuracy of the method are demonstrated with the determination of triamcinolone acetonide in pharmaceutical preparations. Key words triamcinolone acetonide - fluorimetry - CTMAB - β-cyclodextrin - pharmaceutical analysis CLC number O 657.39 Foundation item: Supported by the National Natural Science Foundation of China (20275028)Biography: Pan Zu-ting (1945-), male, Professor, research direction: analytical chemistry.
文摘Ce(Ⅲ)-ALC-F complex can react with hsDNA to form an electrochemically non-active supermolecular complex Ce(Ⅲ)-ALC-F-DNA in the buffer solution of (CH2)6N4(pH=4.9), which results in the decrease of the peak current of Ce(Ⅲ)-ALC-F. This method can be applied to determine DNA concentration. In addition, by using fluorimetric and UV-spectrophotometric methods with studies of denatured DNA and the effect of NaCl solution , it is also found that the binding mode is intercalation.
基金The authors are gratelbl for financial supports IYom the National Natural Science roundation of Chinathe Educational Commiss
文摘A new spectrofluorimetric method for determination of trace terbium based on its reaction with 2.6-his-(1'-phenyl-3'-methyl-5'- pyridinediacyl (H_2PMBPP) and N- cetylpyridium bromide (CPB). at an apparent pH=5.0 provided by a hexamethylenetetramine (5% w/w)-hydrochloric acid buffer,is propesed. The calibration graph is linear in the ran ge from
基金Project supported by the National Natural Science Foundation of China
文摘The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.
基金Project supported by the National Natural Science Foundation of China
文摘Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5~100μg/mL.