The stability constant of the DTPA-metal complex is the second highest, next only to the CyDTA-metal complex. DTPA is a free acid that has low solubility in water. DTPA is useful as a strong masking reagent. It is also used for the extraction of metal ions such as Al, Fe, Ma, Zn, Cu, Cd, and Ni from soil at pH 5.3.
2. J. Kinnunen, et al., Rapid Determination of the Rare Earths in Phosphate Rock. Chem Anal. 1967;56:24-25.
3. J. Kinnunen, et al., Determination of Rare Earths in Phosphate Rock by Atomic Absorption Flame Photometry. Chem Anal. 1967;56:25-27.
4. W. A. Norvell, Comparison of Chelating Agents as Extractants for Metals in Diverse Soil Materials. Soil Sci Soc Am J. 1984;48:1285-1292.