Liquid-Phase Oxidation of Organic Reagents in Inorganic Analysis

Abstract

It was shown that the sensitivity of analytical procedures using organic reagents can be significantly increased if a poorly soluble complex of an element with an analytical reagent is oxidized to the products of complete oxidation of organic compounds (CO₂ , H₂O, and NH₃or N₂for nitrogen-containing reagents). Knowing the amount of the consumed oxidant, one can easily determine the amount of the organic constituent of the complex and, hence, the amount of the complex-forming element. Vanadium salts were proposed as oxidants. The effects of medium acidity, oxidant concentration, time of heating, and temperature on the completeness of oxidation were studied. Based on the results obtained, it was demonstrated for a number of organic compounds that liquid-phase oxidation is highly promising and that trace amounts of elements can be determined by conventional titrimetric methods. The determination of phosphorous with diantipyrylmethane is illustrated by an example (1 mL of a 0.1 M vanadate solution corresponds to 10 μg phosphorous).