New robust and efficient liquid membranes for conductive vial electromembrane extraction of acids with low to moderate hydrophilicity in human plasma

The current paper reports two new, robust, and efficient conditions for electromembrane extraction of acidic substances from human plasma. Two systems were developed based on eutectic solvents: A1 ("A" for acid) comprised dodecyl methyl sulfoxide and thymol in 1:2 ratio (w/w) as liquid membrane, while A2 used [6-methylcoumarin:thymol (1:2)]:2-nitrophenyl octyl ether in 2:1 ratio (w/w). The performance of A1 and A2 was characterized by extraction of 31 acidic model analytes (pharmaceutical drugs and nutrients) spiked into 100 µL human plasma diluted 1:1 (v/v) with phosphate buffer pH 7.4. The acceptor solution was 50 mM NH