Highly Efficient Extraction Procedures Based on Natural Deep Eutectic Solvents or Ionic Liquids for Determination of 20-Hydroxyecdysone in Spinach

Abstract

A novel, efficient extraction procedure based on natural deep eutectic solvents (NADES) and ionic liquids (ILs) for determination of 20-hydroxyecdysone (20-E) in spinach has been developed. NADES, the first green extraction agent, with different hydrogen bond donors and acceptors are screened in order to determine extraction efficiencies. NADES consisting of lactic acid and levulinic acid at a molar ratio of 1:1 exhibits the highest yields. ILs, the second green extraction agent, with various cations and anions are also investigated, where [TEA] [OAc]·AcOH, χAcOH = 0.75 displays the highest recovery. Moreover, NADES-SLE and IL-SLE (SLE, solid-liquid extraction) parameters are investigated. Using the obtained optimized method, the recoveries of the target compound in spinach are above 93% and 88% for NADES-SLE and IL-SLE procedure, respectively. The methods display good linearity within the range of 0.5–30 μg/g and LODs of 0.17 µg/g. The proposed NADES-SLE-UHPLC-UV and IL-SLE-UHPLC-UV procedures can be applied to the analysis of 20-E in real spinach samples, making it a potentially promising technique for food matrix. The main advantage of this study is the superior efficiency of the new, green extraction solvents, which results in a significant reduction of extraction time and solvents as compared to those in the literature.

Deep Eutectic Solvents Application in Food Analysis

“…Taking into consideration the GAC principles, the downscaling of sample treatment has shown some advantages, such as low consumption of samples (10 µL-25 mL), low amounts/volumes of reagents and organic solvents (10-400 µL), a reduction and simplification of procedures, and high enrichment factors. For this reason, although some applications in which larger volumes of DES (even reaching 20 mL) can be found [21,24,29,32,35,37,41,58,69], most hydrophilic DESs have been applied in miniaturized liquid-based extraction techniques (see Table 1). In this sense, DESs have been applied in the three main modes of liquid-phase microextraction (LPME): dispersive liquid-liquid microextraction (DLLME), hollow-fibre liquidphase microextraction (HF-LPME) and single drop microextraction (SDME).…”

“…On the other hand, its properties, such as viscosity or density, are those that will allow better or worse retention of the analytes [1,6]. In general, hydrophilic DESs tend to have a relatively high viscosity, which makes an effective mass transfer in the extraction processes difficult, so a common practice to reduce their viscosity to suitable values consists in the addition of a known amount of water to hydrophilic DESs using the heating method [15,21,24,25,29,31,33,35,37], in which known concentrations of the three components (HBD, HBA and water) are mixed under constant stirring in a water bath (generally at 50 • C) until a homogeneous and transparent liquid is obtained. In certain cases, water has even been replaced by an organic solvent, such as ethanol (EtOH) or MeOH [43].…”

“…After the application of the DESs as extraction solvents in the above-mentioned procedures, analytes have generally been determined by HPLC or ultra-high-performance liquid chromatography (UHPLC) using different detection systems, such as UV [21,[29][30][31][32]44,52,57,70,73], diode array detector (DAD) [10,25,35,36,59,67], FD [37,39,60,65], tandem mass spectrometry (MS/MS) [33], as a result of their appropriate solubility in the mobile phase, or ICP-MS, this last for free seleno-amino acids determination [24]. However, they have also been separated and detected by UV-Vis spectrophotometry [14,22,38,40,45], atomic absorption spectroscopy (AAS) [11,23,47,68], slotted quartz tube-flame AAS [48,49], hydride generation AAS [12], graphite furnace AAS [15,26,42], ETAAS [13,27,46,50,51,71] and ICP-optical emission spectroscopy (OES) [28].…”

Ionic Liquids for Development of Heterogeneous Catalysts Based on Nanomaterials for Biocatalysis

“…Accordingly, ILs have a wide range of industrial applications. Due to their modulated polarity, acidity, and viscosity, ILs are interesting alternatives for conventional organic solvents [36], hazardous catalysts [37], and absorbent and extraction agents [38,39]. Ionic liquids have also been reported as effective enzyme stabilizers [31,40].…”

New phases for analytical scale extraction from plants: Current and future trends

“…NADESs (together with ILs) have also been investigated in the extraction of ecdysteroids, and, in particular, 20-hydroxyecdysone, from spinach (Spinacia oleracea L.) and several advantages were found, including higher selectivity, simplicity, efficiency, and rapidity, as well as the recovery and much lower consumption of organic solvents, in comparison with conventional methods [54]. In addition, it has been shown that DESs are also able to extract volatile compounds.…”