This paper describes a simple and highly selective method for separation, preconcentration and spectrophotometric determination of trace amounts of mercury. The method is based on the flotation of an ion-associate of HgI4(2-) and ferroin between aqueous and n-heptane interface at pH 5. The ion-associate was then separated and dissolved in acetonitrile to measure its absorbance. Quantitative flo...

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...

A modified version of the short-lived BrO3(-)-H2PO2(-)-Mn(II)-N2 oscillator, the BrO3(-)-H2PO2(-)-acetone-dual catalyst system, where the catalyst pair can be Mn(II)-Ru(bpy)3SO4, or Mn(II)-ferroin, or Mn(II)-diphenylamine, shows long-lasting batch oscillations in the potential of a Pt electrode and in colour, accompanying periodic transitions between the oxidised and reduced forms of the cataly...

A gas free analogue of the Belousov-Zhabotinsky reaction catalysed by ferroin and encapsulated in phospholipid stabilised vesicles is reported. A reaction mixture which exhibits spontaneous oscillation and excitation transfer between vesicles was formulated. By adjusting the reagent concentrations a quiescent state with fewer spontaneous oscillations was achieved. Using relatively low power las...

Two simple methods are described for the determination of ethionamide (ETM) in bulk drug and tablets using cerium (IV) sulphate as the oxidimetric agent. In both methods, the sample solution is treated with a measured excess of cerium (IV) solution in H2SO4 medium, and after a fixed standing time, the residual oxidant is determined either by back titration with standard iron (II) solution to a ...

Gravimetric, titrimetric, polarographic, optical and radiochemical methods have been reported for the determination of iron(II) and (III). Numerous reagents have also been reported for the spectrophotometric determination of Fe(II); for example, thiocyanate, dipyridine, tripyridine and 1,10-phenanthroline. The 1,10phenanthroline family has been extended to the use of dihydroxy, dimethyl, nitro ...