# Green Analytical Chemistry--Recent Innovations
## 3 Innovations in Green Analytical Techniques
### Sustainable Sample Preparation
[PERSON] also highlights alternative phase separation techniques, such as salting-out and gas-assisted flotation, which eliminate the need for centrifugation, thus facilitating automation and high-throughput analysis. Furthermore, automation in DLLME, incorporating flow-based, batch, and in-syringe systems, has been a key focus, ensuring greater reproducibility and reduced solvent consumption. These innovations position DLLME as a sustainable and efficient method in modern green analytical sample preparation [52]. [PERSON] et al. [57] explored innovative approaches in liquid-phase microextraction (LPME) for aromatic amines, emphasizing the potential of hollow fiber liquid-phase microextraction (HF-LPME) and parallel artificial liquid membrane extraction (PALME). Their findings revealed that PALME offers significantly higher recoveries compared to HF-LPME, while also being less labor-intensive and greener, as it requires much smaller volumes of organic solvents. They highlighted PALME's suitability for complex biological matrices, such as urine, due to its ability to reduce matrix interferences and achieve low limits of detection in the nanogram per liter range. These advancements demonstrate how miniaturized and efficient sample preparation techniques can address analytical challenges in environmental and biomedical studies. As illustrated in Figure 3, both HF-LPME and PALME share similar fundamental extraction principles but differ in their membrane configurations, solvent choices, and processing efficiency. The choice of membrane material plays a critical role in analyte selectivity, stability, and recovery efficiency. HF-LPME, with its hollow fiber structure, allows for precise control over extraction conditions but requires manual handling, making it less practical for high-throughput applications. PALME, in contrast, offers a more automated, scalable, and reproducible alternative, making it an attractive choice for laboratories requiring batch processing of multiple samples. The experimental results further demonstrated that PALME exhibited higher extraction recoveries for most aromatic amines, attributed to the increased surface area and enhanced mass transfer kinetics enabled by its membrane structure. The shorter extraction time and automationpotential of PALME present a significant advantage over HF-LPME, particularly for applications in environmental and pharmaceutical analysis. However, HF-LPME remains a viable option for selective, small-scale extractions where high enrichment factors are required. Both SPME and LPME have seen integration with advanced analytical instruments, such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), for comprehensive and highly sensitive analyses. These techniques are increasingly employed in trace analysis of environmental contaminants, VOCs, and bioactive compounds, demonstrating their versatility and relevance in addressing contemporary analytical challenges. As research continues, innovations such as the incorporation of ionic liquids and deep eutectic solvents in microextraction systems further bolster the green credentials of these methods. By reducing resource consumption and improving analytical performance, SPME and LPME exemplify the synergy between technological innovation and sustainability in modern analytical chemistry. SPME is a well-established technique in analytical chemistry due to its solvent-free nature, minimal sample preparation, and high sensitivity, making it an attractive tool for environmentally friendly analysis. While its adoption in routine industrial workflows is not yet widespread due to scalability challenges, advancements in automated SPME systems and fiber durability are expanding its applicability, particularly in quality control and high-throughput screening.