Separation and determination of selenium in rocks, marine sediments and plankton by direct evolution with the bromide-condensed phosphoric acid reagent.

摘要: Abstract A new method is presented for the quantitative separation and determination of selenium by direct evolution with bromide-condensed phosphoric acid reagent (Br − -CPA) from rocks, marine sediments plankton. In reaction Br −1 -CPA, selenium(IV) (VI) in solid samples are evolved as tetrabromide, can be collected an absorbing solution 0.3 M hydrochloric 06 perchloric add (1:1), then determined spectrophotometrically 4-substituted o -phenylenediamines followed extraction resulting 5-substituted piazselenol into toluene. Elemental selenide do not react but after oxidation to selenite potassium iodate. Therefore, successive distillations, first -CPA second IO 3 -Br give a satisfactory means diflerential (VI), elemental selenide. This successfully applied neutron-activation analysis standard rock samples, plankton, giving good reliable results.