Homogeneous liquid–liquid extraction using perfluorooctanesulfonic acid and calcium and its application to the separation and recovery of vitamin B12 |
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Authors: | Shigekatu Oshite Shukuro Igarashi |
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Abstract: | A new phase separation phenomenon was observed in which the perfluorooctanesulfonate ion (PFOS−) 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−]T = 7 × 10−3 mol dm‐3 and Ca2+]T = 1.1 mol dm‐3. When these findings were applied to the homogeneous liquid–liquid extraction of vitamin B12, the extraction percentage (E) was 83% and the concentration ratio (ie Va/Vs, where Va is the volume of the aqueous phase and Vs is the volume of the sedimented liquid phase) was a maximum of 149. The recovery of vitamin B12 was achieved by adding the propanol–acetone (20 : 80 v/v%) mixed solvent to the sedimented liquid phase; the vitamin B12 precipitated and was filtered. Both the PFOS− and Ca2+ were removed by dissolution in the mixed solvent. The recovery percentage of vitamin B12 was 78%. © 1999 Society of Chemical Industry |
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Keywords: | homogeneous liquid– liquid extraction perfluorooctanesulfonate ion calcium ion ion‐pair association separation and recovery of vitamin B12 |
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