Spectrophotometric determination of osmium with 1,5-diphenylcarbazide

The formation of the bluish violet osmium-diphenylcarbazide complex in weakly acidic solution is utilized for the determination of osmium by spectrophotometry. When measurements are made at 560 nm, after extraction of the complex into isobutyl methyl ketone, Beer's law is obeyed up to 150 μg of osmium. Relatively few ions interfere, and these can be masked with EDTA and fluoride. © 1982.