Uphill, Rapid, and Selective Transport of Picrate through Dichloromethane Membrane

✍ Scribed by A. Safavi; L. Fotouhi

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 69 KB
• Volume: 58
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1997.1548

✦ Synopsis

The transport of picrate anion against its concentration gradient by coupling it with movement of thiocyanate ion in the opposite direction is reported. The membrane containing toluidine blue separated two aqueous phases, one containing picrate and borate buffer (pH 9) and the other containing picrate, potassium thiocyanate, and borate buffer (pH 9). The picrate anion was accumulated against the concentration gradient in the aqueous phase containing thiocyanate. The rate of picrate transport increased with increasing toluidine blue concentration in the membrane; in the absence of toluidine blue, transport of picrate did not occur. The effect of thiocyanate counterions such as potassium, sodium, and ammonium was examined. No change in the rate of transport was observed by changing the counterion. The effect of other anions on the rate of picrate transport was examined. The energy of this movement comes from the simultaneous countertransport of thiocyanate.