Solvent extraction separation of molybdenum(VI) with dibenzo 18-Crown-6 from chloride solutions

Molybdenum(VI) was quantitatively extracted wtih 0.01 M dibenzo 18-Crown-6 (DB18C6) in dichloroethane from 3-8 M hydrochloric acid, and was stripped with 0.05 M hydrochloric acid. After drywashing it was determined spectrophotometrically as its complex with Tiron at 390 nm. Other crown ethers such as 15C5, DC18C6 and DB24C8 were ineffective for extraction but with DB18C6 the extraction was quantitative. Among diluents only dichloroethane was effective. The stripping was complete with dilute solutions (0.05 M) of hydrochloric acid. Molybdenum(VI) was separated from large number of elements with which it is generally associated in minerals. The method was extended for analysis of Mo in real samples. The relative standard deviation was plus/minus1.2%.