The current manuscript, a continuation in a series on generic EME systems aimed at commercial equipment, focuses on developing such systems for acidic compounds displaying low-tomoderate hydrophilicity. As such, the study is not intended as a method for the specific analytes used, but rather to enable generalization of these systems. Previous papers in this series have concerned generic systems for basic substances of high and low hydrophilicity, in human plasma samples . EME of acidic substances was first reported in 2007 , using 1-heptanol as liquid membrane. Since then, most methods have utilized this and other aliphatic alcohols, with 1-octanol being the most predominant one. Alcoholic liquid membranes work by acting as a hydrogen bond donor (HBD) that interacts with the strong hydrogen bonding accepting (HBA) properties of ionized acids, thereby improving partitioning into the organic phase . 1-octanol has a water solubility of 0.54 mg mL -1 and is therefore at the limit of what can be recommended. 1-octanol also appears throughout literature to have limited compatibility with complex samples , often requiring substantial dilution of the sample prior to extraction . Therefore, the current work focused on identifying and characterizing new suitable liquid membrane solvents, followed by optimization of other operational parameters. This resulted in the identification of two effective systems for EME of acidic substances in blood plasma, marking significant enhancements in performance and compatibility, and setting the stage for future robust EME applications for acidic analytes.