Rapid extraction and spectrophotometric determination of vanadium(V) with 2′-hydroxy-4-methoxy-5′-methyl chalkone oxime (HMMCO)

2′-Hydroxy-4-methoxy-5′-methyl chalkone oxime (HMMCO) is used for the extraction and spectrophotometric determination of microgram quantities of vanadium. HMMCO forms a green colored complex with vanadium at 9 M HCl extracted into chloroform. The complex absorbs maximum at 630 nm. Beer's law holds good over the concentration range of 2.7 to 94.0 μg of vanadium per ml. The Ringbom plot shows the effective working range of 4.5 to 67.0 μg of vanadium per ml. The extracted species shows the composition to be 1:2 (V:HMMCO). Vanadium can be extracted quantitatively without any serious interference of the foreign ions. It is possible to extract and determine vanadium quantitatively from binary mixtures that contain niobium, tantalum, or titanium. The method is also applicable to some ores.