Homogeneous liquid–liquid extraction using perfluorooctanesulfonic acid and calcium and its application to the separation and recovery of vitamin B12

✍ Scribed by Shigekatu Oshite; Shukuro Igarashi

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 90 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199912)74:12<1183::aid-jctb163>3.0.co;2-y

✦ Synopsis

A new phase separation phenomenon was observed in which the per¯uorooctanesulfonate ion (PFOS À ) and calcium ion form an ion-pair associator and the sedimented liquid phase occurs from the homogeneous aqueous solution. This phenomenon was observed in the neutral pH region at room temperature (25 °C). The optimum concentration conditions for the reagents were [PFOS À ] T = 7Â 10 À3 mol dm -3 and [Ca 2 ] T = 1.1 mol dm -3 . When these ®ndings were applied to the homogeneous liquid± liquid extraction of vitamin B 12 , the extraction percentage (E) was 83% and the concentration ratio (ie V a /V s , where V a is the volume of the aqueous phase and V s is the volume of the sedimented liquid phase) was a maximum of 149. The recovery of vitamin B 12 was achieved by adding the propanol±acetone (20:80 v/v%) mixed solvent to the sedimented liquid phase; the vitamin B 12 precipitated and was ®ltered. Both the PFOS À and Ca 2 were removed by dissolution in the mixed solvent. The recovery percentage of vitamin B 12 was 78%.