# Green Analytical Chemistry--Recent Innovations
## 3 Innovations in Green Analytical Techniques
### Ionic Liquids and Eutectic Solvents  
The use of ionic liquids (ILs) and eutectic solvents (ESs) in analytical chemistry has gained significant attention due to their alignment with the principles of green chemistry. These solvents serve as innovative and sustainable alternatives to traditional organic solvents, offering unique physicochemical properties, such as low volatility, high thermal stability, and tunable solubility. Ionic liquids, composed entirely of ions, can be designed with specific cation-anion combinations to tailor their properties for various analytical  
Figure 3: Schematic representation of the HF-LPME and PALME setups, including membrane materials, organic solvents, and experimental conditions used in this study. HF-LPME employs a polypropylene hollow fiber as the supported liquid membrane (SLM), while PALME utilizes a polyvinylidene fluoride (PVDF) membrane. The figure highlights the key differences in extraction efficiency, membrane structure, and agitation conditions, demonstrating PALME’s suitability for high-throughput and automated applications. Abbreviations: AA, aromatic amines; DHE, dihexylletter; HCl, hydrochloric acid; NaOH, sodium hydroxide; PP, polypropylene; PVDF, polyvinylidene fluoride; UD, undecane [57]. Copyright © 2023, [PERSON] et al. applications. Their negligible vapor pressure reduces environmental emissions, while their high solvating power enhances the extraction efficiency of polar and non-polar analytes. Recent advancements in ILs include the development of task-specific ionic liquids (TSILs), engineered for targeted analytical purposes, such as the selective extraction of heavy metals, pharmaceuticals, or bioactive compounds from complex matrices. [PERSON] et al. [58] emphasized the unique advantages of task-specific ionic liquids (TSILs) in separation processes, particularly for rare earth elements (REEs). Their work highlighted that TSILs, tailored with functional groups such as carbamoylmethylphosphine oxide (CMPO) or diglycolamide (DGA), offer exceptional selectivity and efficiency by combining ion-exchange and coordination mechanisms. These TSILs not only enhance extraction performance but also reduce the environmental impact by minimizing solvent loss and enabling recycling. For instance, CMPO-based TSILs demonstrated superior performance in separating actinides and lanthides under acidic conditions, reinforcing the potential of TSILs as green alternatives in advanced separation technologies. [PERSON] et al. [59] developed a novel residue analysis method for task-specific ionic liquids (TSILs) in environmental matrices such as water, soil, and plants. By employing high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with accelerated solvent extraction (ASE), they achieved detection limits as low as 10\({}^{-15}\) g for compounds like 1-aminoethyl 1-3-methylimidazolium tetrafluoroborate ([C\({}_{2}\)NH\({}_{2}\)MIm]BF\({}_{4}\)) and 1-hydroxy-3-methylimidazolium tetrafluoroborate ([HOEMI]BF\({}_{4}\)). Their study highlighted the high recovery rates of TSILs in water and soil, demonstrating the effectiveness of optimized extraction solvents, such as water-methanol mixtures, for complex matrices. This approach offers a sensitive and reliable framework for monitoring TSIL residues and assessing their environmental impact. Traditional solvent extraction methods, such as CMPO dissolved in TBP with xylene, benefit from the thermal stability of TBP, which minimizes evaporation losses and enhances extraction efficiency. However, task-specific ionic liquids (TSILs) provide distinct advantages over conventional liquid-liquid extraction methods. Unlike TBP-based extractions that require organic solvents, TSILs are non-volatile, recyclable, and offer improved selectivity for specific target analytes. Additionally, TSILs facilitate phase separation without the need for large solvent volumes, reducing environmental impact and making them a more sustainable alternative in green sample preparation techniques.