Extraction across supported liquid membranes by use of electrical fields

The method of electrokinetic migration that used electrical fields to extract supported liquid membranes (SLM) was demonstrated. Several hydrophobic basic drug substances were extracted protonated molecules from a 300 μL acidic sample solution through a SLM, consisting 15 μL 2-nitropheynl octyl ether (NPOE) into 30 μL 10 mmol L^-1hydrochloric acid (HCL) as the acceptor solution, applying 300 V dc. The electrical potential difference was the force driving extraction of the charged analytes, without any pH gradient across the SLM. The use of electrical potential difference was found to be a significant driving force for SLM extraction a pH gradient. The kinetic advantage of using electrical field was found also found to be significant, when extractions were performed from small sample volumes.