Eluatie

Eluatie is a process in analytical chemistry and materials science in which solutes are displaced from a solid phase and carried away by a liquid. In chromatography and solid-phase extraction, eluatie describes the operation that releases analytes from a stationary phase into a mobile phase, yielding the eluate, the liquid stream that contains the dissolved components. The term is sometimes used interchangeably with elution or eluate in non-English literature, and its exact meaning can vary by field.

The mechanism of eluatie depends on the balance between adsorption to the stationary phase and desorption into the liquid; factors such as solvent strength, polarity, flow rate, temperature, and column characteristics determine which solutes are released and when. Isocratic eluatie uses a constant solvent composition, while gradient eluatie changes solvent strength during the run to separate mixtures with a wide range of affinities. The choice of stationary phase, particle size, and porosity also influence resolution, selectivity, and run time.

Applications of eluatie include purification and isolation of organic compounds, proteins and nucleic acids in biochemistry, cleanup of complex samples for environmental or food analysis, and quality control in pharmaceutical manufacturing. The composition of the eluate is typically monitored by analytical detectors such as UV-Vis spectrophotometry, fluorescence, or mass spectrometry, and the eluate is collected in fractions for further processing or identification.