The first set of generic liquids membrane and associated experimental conditions (termed A1 and A2) was developed for acidic substances with 0.5 ≤ log P ≤ 6.0. The systems were fully compatible with human plasma sample and extracted most analytes within their defined extraction windows exhaustively (R > 85%) or near-exhaustively, which represent a major improvement to previously known EME systems for acids. In addition, they can be applied for EME of basic substances as well, although they are not recommended as a first choice. Adding A1 and A2 to previously published (first-choice) generic systems, methods for EME in commercial equipment of a wide variety of basic and acidic substances are now available. In forthcoming research, similar conditions will be investigated for acidic substances with log P < 0.5. Also, despite excellent and robust performance of A1 and A2, one limitation to these systems is their formulation of multiple different components in the liquid membrane mixture. Future research may therefore also explore simpler liquid membranes that can deliver the same performance.