Accelerated Liquid Extraction
Accelerated solvent extraction (ASE), also known as superheated liquid extraction (SHLE), has been widely used for the isolation of natural products since its appearance two decades ago. This type of solid–liquid extraction is based on the combined application of high pressure and temperature to take benefits from solvent properties under these conditions, such as increased diffusivity of the solvent into the plant matrix and increased solubility of analytes in the extractant phase. The main advantages of ASE when compared to conventional protocols frequently used for isolation of natural products can be considered to be shorter extraction time, reduced solvent consumption, lower cost, increased leaching efficiency and ease of scaling‐up the extraction process to industrial level. The latter characteristic is of particular interest to extract natural compounds with marked bioactivity for production of drugs, nutraceuticals, foods and cosmetics, among others. Two different modes, static and dynamic ASE, are discussed here, emphasizing the main differences between them and paying special attention to the extraction devices used. A final section is focused on comparison of ASE to other modern extraction techniques and on the main application fields covered in the scene of natural products.