Improved extraction of fluoroquinolones with recyclable ionic-liquid-based aqueous biphasic systems

Abstract

In the past few years, the improvement of advanced analytical tools allowed to confirm the presence of trace amounts of metabolized and unchanged active pharmaceutical ingredients (APIs) in wastewater treatment plants (WWTPs) as well as in freshwater surfaces. It is known that the continuous contact with APIs, even at very low concentrations (ng L −1 -μg L −1 ), leads to serious human health problems. In this context, this work shows the feasibility of using ionic-liquid-based aqueous biphasic systems (IL-based ABS) in the extraction of quinolones present in aqueous media. In particular, ABS composed of imidazolium-and phosphonium-based ILs and aluminiumbased salts (already used in water treatment plants) were evaluated in one-step extractions of six fluoroquinolones (FQs), namely ciprofloxacin, enrofloxacin, moxifloxacin, norfloxacin, ofloxacin and sarafloxacin, and extraction efficiencies up to 98% were obtained. Despite the large interest devoted to IL-based ABS as extractive systems of outstanding performance, their recyclability/ reusability has seldomly been studied. An efficient extraction/cleaning process of the IL-rich phase is here proposed by FQs induced precipitation. The recycling of the IL and its further reuse without losses in the ABS extractive performance for FQs were established, as confirmed by the four consecutive removal/extraction cycles evaluated. This novel recycling strategy supports ILbased ABS as sustainable and cost-efficient extraction platforms.

Novel aqueous biphasic system based on ethyl lactate for sustainable separations: Phase splitting mechanism

“…The tie-lines of the ternary systems were determined according to the procedure previously described in literature [9]. Each tie line was determined using lever-arm rule according to the following equations:…”

“…Similar to molten salts, ionic liquids are compounds solely composed of ions but with melting points close to room temperature. Due to their physicochemical properties, ionic liquids have been implemented in aqueous two-phase systems for extraction of various biologically active substances, including proteins [6], amino acids [7], antioxidants [8], antibiotics [9], pesticide [10] and mycotoxins [11]. However, most ionic liquids have low biodegradability and low biocompatibility.…”

Liquid–Liquid Phase Equilibria of Aqueous Biphasic Systems Based on Glycerol Formal: Application on Tetracycline Recovery from Water

“…Another alternative is to use an ionic liquid as a hydrophilic substance to form a two-phase system 6 . Due to their physicochemical properties and tunability, ionic liquids have been implemented in aqueous two-phase systems for extraction of various biologically active substances, such as proteins 7 , antioxidants 8 and antibiotics 9 . However, commonly used ionic liquids based on imidazolium and pyridinium cations show considerable toxicity to biomolecules, microorganisms, plants and animals 10 as well as low biodegradability 11 .…”

Panorama da pesquisa sobre tratamento e reúso de efluentes da indústria de antibióticos

“…Extraction processes adopting nonpolar or foam phases that favor the removal by liquid-liquid processes were also found in this search. Almeida et al 53 analyzed the potential for removal of fluoroquinolones from the addition of an ionic solution to the effluent. The difference in polarity between these solutions (extractor and effluent) caused antibiotic residues to be removed from the effluent to the extractor solution.…”