5928-63-2

Solid.

a-Benzoinoxime is used most frequently for the determination of copper(II), but it gives highly stable complexes with molybdenum(VI), tungsten(VI) and vanadium(V), which are insoluble in water and can be extracted with chloroform.
Copper can be quantitatively precipitated from hot solutions containing ammonium hydroxide or sodium tartrate. The excess reagent ensures the quantitative precipitation of the copper but it requires careful work to avoid contamination of the precipitate by the excess of the reagent. Hence combined solvent extraction-spectrophotometric measurements have proved more suitable than the gravimetric method. The absorption maximum of the copper chelate in chloroform solution is at 440 nm.

Organic intermediates and photographic chemicals, analytical reagent for determination of metals.