Improved monitoring of aqueous samples by the preconcentration of active pharmaceutical ingredients using ionic-liquid-based systems

resumo

Fluoroquinolones (FQs) and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are two classes of Active Pharmaceutical Ingredients (APIs) in widespread use in human healthcare and as veterinary drugs, and that have been found throughout the water cycle in the past years. These two classes of APIs are commonly present in aqueous streams in concentrations ranging from ng L-1 to mu g L-1. Despite such low concentrations, these contaminants tend to bioaccumulate, leading to serious environmental and health issues after chronic exposure. The low concentrations of FQs and NSAIDs in aqueous media also render difficult identification and quantification, which may result in an inefficient evaluation of their environmental impact and persistence. Therefore, the development of alternative pre-treatment techniques for their extraction and preconcentration from aqueous samples is a crucial requirement. In this work, liquidliquid systems, namely ionic-liquid-based aqueous biphasic systems (IL-based ABS), were tested as simultaneous extraction and preconcentration platforms for FQs and NSAIDs. ABS composed of imidazolium-, ammonium-and phosphonium-based ILs and a citrate-based salt (C6H5K3O7) were evaluated for the single-step extraction and enrichment of three FQs (ciprofloxacin, enrofloxacin and norfloxacin) and three NSAIDs (diclofenac, naproxen and ketoprofen) from aqueous samples. Outstanding one-step extraction efficiencies of APIs close to 100% were obtained. Furthermore, the preconcentration factors of both FQs and NSAIDs were optimized by an appropriate manipulation of the phase-forming components compositions to tailor the volumes of the coexisting phases. Preconcentration factors of 1000-fold of both FQS and NSAIDs were obtained in a single-step process, without reaching the saturation of the IL-rich phase. The preconcentration of APIs up to mg L-1 allowed their easy and straightforward identification and quantification by a High-Performance Liquid Chromatography (HPLC) system coupled to an UV detector, as shown for both model systems (distilled water) and real effluent samples from a waste-water treatment plant.

palavras-chave

SOLID-PHASE EXTRACTION; ENVIRONMENTAL RISK-ASSESSMENT; PERSONAL CARE PRODUCTS; WATER TREATMENT PLANTS; BIPHASIC SYSTEMS; WASTE-WATER; SEPARATION PROCESSES; EMERGING POLLUTANTS; AQUATIC ENVIRONMENT; 2-PHASE SYSTEMS

categoria

Chemistry; Science & Technology - Other Topics

autores

Almeida, HFD; Freire, MG; Marrucho, IM

Grupos

G5 - Materiais Biomiméticos, Biológicos e Vivos

Projectos

CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)

Igy Technology: A Purication Platform using Ionic-Liquid-Based Aqueous Biphasic Systems (IGYPURTECH)

agradecimentos

This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement. H. F. D. Almeida acknowledges FCT for the PhD grant SFRH/BD/88369/2012. M. G. Freire acknowledges the funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 337753. I. M. Marrucho acknowledges the FCT Investigator Program (IF/363/2012). This work was carried out under the Research unit GREEN-it "Bioresources for Sustainability" (UID/Multi/04551/2013). The authors thank Antonio Alcada from EPAL - "Grupo Aguas de Portugal" for kindly providing the WWTP effluent.