Synergistic extraction of amoxicillin from aqueous solution by using binary mixtures of Aliquat 336, D2EHPA and TBP

• Amoxicillin extraction by Aliquat 336, D2EHPA and TBP.
• Synergistic amoxicillin extraction obtained by Aliquat/TBP and D2EHPA/TBP mixture.
• Maximum 90.4% extraction percentage by 10:2 molar ratio Aliquat/TBP mixture.

Amoxicillin extraction was conducted using the single organic extractant namely trialkylmethylammonium chloride (Aliquat 336), di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and tributylphosphate (TBP) and followed by the synergistic extraction using the binary mixtures of the mentioned extractants. Maintaining an initial pH of amoxicillin aqueous solution at 10 yielded the highest extraction percentage for all extractants. Increasing extractant concentrations from 2 to 12 mM produced the positive effect on amoxicillin separation for all extractants except for TBP with the highest extraction percentage and distribution coefficient reported at 86.2 ± 1.10% and 6.25 ± 0.267, respectively when maintaining Aliquat 336 at 12 mM. Synergistic extraction was observed when the mixtures of D2EHPA and TBP as well as Aliquat 336 and TBP were employed with the maximum extraction percentage and distribution coefficient reported at 90.4 ± 0.39% and 9.44 ± 0.459, respectively when maintaining the molar ratio of Aliquat 336 to TBP at 10:2.