chromatografen

The chromatograph is a device used to separate and analyze the components of a mixture by chromatography. Chromatography relies on the differential partitioning of compounds between a mobile phase and a stationary phase as the mixture is transported through a column or a planar medium.

In operation, a sample is introduced into a flow of carrier gas (in gas chromatography) or a liquid (in liquid chromatography). The mobile phase moves through a column containing the stationary phase, and different compounds interact with the stationary phase to different extents. As a result, they elute at different times and are detected by a suitable detector. The detector generates a signal that is recorded as a chromatogram, typically with peaks corresponding to individual components and peak areas proportional to concentration.

Most modern chromatographs fall into two main families: gas chromatography (GC) and liquid chromatography (LC), the latter including high-performance liquid chromatography (HPLC) and ultra-high-performance LC (UHPLC). A typical instrument comprises an injector, a column, a detector, and a data system. The mobile phase is supplied by pumps or carriers, and columns may be packed or capillary. Detectors vary from flame ionization and thermal conductivity to ultraviolet/visible absorbance, refractive index, fluorescence, and mass spectrometry, among others.

Applications span pharmaceuticals, environmental analysis, food and fragrance, clinical diagnostics, and forensics. Chromatography offers high sensitivity, selectivity, and the ability to analyze complex mixtures, but performance depends on careful method development, calibration, and maintenance of the equipment and columns.