Author :
Ensafi, A. A.,Safavi, A
Title of Article :
Sensitive spectrophotometric kinetic determination of osmium by catalysis of the pyrogallol red-bromate reaction
Title Of Periodical :
ANALYTICA CHIMICA ACTA
Descriptors :
Spectrophotometry,Kinetic,Analysis,Osmiurm
Abstract :
Osmium (VIII) is determined by mans of its catalytic effect on the oxidation of pyrogallol red (PGR) by potassium bromate at PH 6.0, 30 C and 545 nm. The decrease in absorbance of PGR (2.5 x 10**-5 M) in the presence of KBrO***3 (0.20 M) over a period of 0-150 s is proportional to the concentration of osmium (VIII) over the range 0-1400 ng ml**-1. The limit of detection of osmium was 0.65 ng ml**-1. The precision and accuracy of the method are described. The effects of the presence of 45 cations and anions on osmium determination were studied. The effects of probable interfrences were competely removed by a single extraction of osmium as osmium tetraoxide into isoburyl methyl ketone and back-extraction into sodium hydroxide solution.
