The success of an analytical method depends on the sample preparation procedures before instrumental analysis. Therefore, a sample preparation procedure is required in order to isolate the selected compounds from the biological and environmental matrix and to eliminate some potential interferences. Also, because many compounds are found in low concentrations in samples, the sample preparation technique must be able to concentrate the analytes and therefore improve the detectability of the analytical method and ensure the samples are in a form that is compatible with the analytical system.

Among the numerous sample preparation procedures, liquid-liquid extraction and solid phase extraction are the most common used for the preparation of samples due to their extraction efficiency and high recoveries. However, it must be noted that these procedures are often tedious and time-consuming as they involve many steps. In addition, large amounts of potentially hazardous organic solvents are required. Therefore, to reduce the amount of organic chemical residues and to increase concentration factors, several microextraction techniques have recently been proposed, including solid-phase microextraction and dispersive liquid-liquid microextraction.

The target of this special issue is to receive original research and review articles that highlight the importance of extraction and preconcentration methods for determination of organic and inorganic compounds in biological and environmental samples with a special focus on the development of effective and low-cost microextraction techniques that utilize a very small volume of the extracting phase.

Potential topics include but are not limited to the following:

• Modern approaches in liquid-based microextraction techniques
• Modern approaches in solid-based microextraction techniques
• Modern approaches in membrane-based microextraction techniques
• Microextraction methods based on green solvents
• Immunosorbents used in microextraction
• Auxiliary energies in liquid-phase microextraction