a simple, rapid and sensitive method has been developed for determination of traces of tellurium (iv) (7.0-120.0 ng/ml) based on it’s catalytic effect on the reduction reaction of lauth’s violet by sulfide ion at ph 4.2. the reaction is monitored spectrophotometrically by measuring the decrease in absorbance of lauth’s viole at 600 nm by the fixed time method. the detection limit is 5.0 ng/ml a...

a simple, rapid and sensitive method has been developed for determination of trances of tellurium (vi) (0.096-1.250 mg/ml) based on its catalytic effect on the reduction reaction of toluidine blue by sulfide ion at ph 4. the reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the dyestuff at 628 nm by the fixed time method. the detection limit is 80 ng/ml and...

A simple, rapid and sensitive method has been developed for determination of traces of tellurium (IV) (7.0-120.0 ng/ml) based on it’s catalytic effect on the reduction reaction of lauth’s violet by sulfide ion at pH 4.2. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of lauth’s viole at 600 nm by the fixed time method. The detection limit is 5.0 ng/ml a...

a catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(ii) id described. the method is based on the catalytic effect of manganese(ii) on the oxidation reaction of ferroin by potassium periodate in acidic media. the reaction is monitored spectrophotometrically at 510 nm by a slope method and mn(ii) is determinable in the range of 1-1000ngml-1. the limit of...

Anew, highly sensitive and selective catalytic kinetic method (CKM) for determination of osmium (VIII) has been established based on its catalytic effect on the oxidation of thionine dye by hydrogen peroxide in alkaline medium. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance band of thionine at 600 nm. Under the optimum conditions, the proposed ...

Herein, we describe a case study into the population dynamics of in vitro selection, using RNA-cleaving DNAzymes as a model system. We sought to understand how the composition of the population can change over time in response to different levels of selection pressure, and how well these changes are correlated with selection of the target phenotype. The model population is composed of 857 DNAzy...

the determination of the optimal distribution of the catalytic activity profile, whichmaximizes the catalytic effectiveness, in created unsteady state conditions, is analyzed andtreated numerically for the case of a simple reaction. it was proven that the modulation, of thetemperature and the reactant concentration of the external bulk fluid, leads to a considerableincrease of the catalytic eff...

A catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(II) id described. The method is based on the catalytic effect of manganese(II) on the oxidation reaction of ferroin by potassium periodate in acidic media. The reaction is monitored spectrophotometrically at 510 nm by a slope method and Mn(II) is determinable in the range of 1-1000ngmL-1</sup...

this study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (v). the method is based upon the catalytic effect ofvanadium (v) on the oxidation of carminic acid by bromate in sulfuric acid media. the reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...