Novel aqueous biphasic system based on ionic liquid for the simultaneous extraction of seven active pharmaceutical ingredients in aquatic environment

Nonsteroidal anti-inflammatory drugs and antibiotics are classes of active pharmaceutical ingredients (APIs), which are continuously contaminating the ecosystem through various anthropogenic activities. Because of their pseudo-persistence in the aquatic environment and their potentially chronic effects on aquatic life, it is important to closely monitor their concentrations in the aquatic environment using a sensitive analytical method. Sustainable aqueous biphasic systems (ABSs) composed of ionic liquids and biodegradable organic salt (sodium malate) were proposed. The phase diagrams of the systems were firstly determined, and [N-4444]Cl-based ABS was selected for the simultaneous extraction and preconcentration of seven APIs. With the developed ABS, extraction efficiencies of APIs close to 100% were obtained. For the developed method, limits of detection (LODs) of 45, 65, 76, 14, 60, 48, and 51 ng L-1 were obtained for indomethacin, ibuprofen, diclofenac, naproxen, ketoprofen, flurbiprofen, and chloramphenicol, respectively, providing from 1216- to 1238-fold improvement as compared with the analysis without preconcentration. From an economic and environmental point of view, we can predict the prospects and competitive position of the method developed.

Automated summary

A sustainable aqueous biphasic system was proposed for the extraction and preconcentration of pharmaceutical residues in water, achieving close to 100% extraction efficiency and detection limits as low as 45ng L-1. This method not only improves analytical efficiency, but also has economic and environmental advantages, indicating promising prospects and competitive position.