Extraction of molybdenum(VI) by several phosphorus-containing organic reagents

Tributyl phosphate (TBP) and triisoamylphosphine oxide (TIAPO) were selected from a number of phosphorus-containing reagents as being suitable for the extraction. The choice was based on the following considerations. Tributyl phosphate is widely known as an easily accessible, highly effective extractant for heavy metal ions. Tributyl phosphate is almost un-ionized due to its low dielectric constant. The TBP does, however, ionize to a small extent in solutions containing some water. This is quite adequate for an electrolytic study of the extractant. The extraction of Mo(VI) by tributyl phosphate has been reported. The compositions of the compounds extracted under various aqueous-phase acidities have been determined. Triisoamylphosphine oxide has not been previously used for Mo(VI) extractions so that it would be of interest to study this property and compare it with TBP