Microextractors

Microextractors are devices designed for the efficient and selective isolation of target analytes from complex sample matrices at a microscopic scale. They typically involve a small volume of extracting phase, often a sorbent material or a liquid-liquid interface, contained within a miniature format such as a coated wire, a packed cartridge, or a membrane. The principle of operation relies on the partitioning of analytes from the sample into the extracting phase based on their physicochemical properties like polarity, hydrophobicity, or affinity for specific functional groups.

The advantages of microextraction techniques include reduced solvent consumption, shorter extraction times, and enhanced sensitivity due to preconcentration of analytes. They are particularly useful when dealing with small sample volumes or when analytes are present at trace levels. Common types of microextraction include solid-phase microextraction (SPME), liquid-phase microextraction (LPME), and matrix solid-phase dispersion (MSPD). SPME utilizes a fiber coated with a stationary phase to adsorb analytes directly from the sample or headspace. LPME involves extracting analytes into a small volume of organic solvent, often held in a needle or drop. MSPD disperses the sample matrix and extracts analytes simultaneously.

Microextractors find applications in various fields, including environmental analysis, food safety, pharmaceutical analysis, and clinical diagnostics. They are often coupled with chromatographic techniques like gas chromatography (GC) or high-performance liquid chromatography (HPLC) for subsequent separation and detection of the extracted analytes. The miniaturization and efficiency of microextractors make them attractive alternatives to traditional extraction methods.