Diantipyrylmethane is a colorimetric reagent for Ti detection, and is also used as a gravimetric and solvent extraction reagent for various kinds of metal ions. This reagent is readily soluble in mineral acids and organic solvents, and slightly soluble in benzene (1.7%) and carbon tetrachloride (0.28%). Diantipyrylmethane forms a yellow complex with Ti in 0.5-4.0 M HCl solution (λmax=385-390 nm, ε=15,000). The resulting Ti complex can be extracted by organic solvents in the presence of I-, SCN-, tartaric acid, or pyrocatechol. The detection range is 0.2-3.0 ppm. Diantipyrylmethane also makes a brown water-soluble complex with Fe in a weak acidic solution.
Solvent extraction, colorimetric detection: Fe (λmax=450 nm, ε=5,400), Mo, Ti, U
Gravimetric detection: Be, Ca, Cd, Co, Cu, Hg, Ir, Os, Pb, Sr, Tl, Zn
1. C. H. Chung, Simultaneous Determination of Iron and Titanium in Silicate Rocks by Using Diantipyrinylmethane with Dual-wavelength Spectrophotometry. Anal Chim Acta. 1983;154:259-265.
2. N. Uehara, et al., Determination of Titanium(III) in River Water by Ion-pair Reversed-phase High-performance Liquid Chromatography with 4,4 EDiantipyrylmethane. Analyst. 1991;116:27-29.