Chromatografie

Chromatografie is a family of analytical techniques used to separate, identify, and quantify components of a mixture. The approach relies on distributing components between a stationary phase and a mobile phase as the latter moves through or over the former, producing different travel rates for different substances.

The separation mechanism depends on differences in partitioning, adsorption, size, or ion exchange between the phases. The result is a temporal or spatial separation that can be measured on a plate, a column, or by detectors coupled to the instrument.

Two broad categories exist: planar chromatography, where the separation occurs on a flat surface such as thin-layer plates or paper; and column chromatography, where a packed or coated column is used. Planar methods include thin-layer chromatography (TLC) and paper chromatography. Column methods include gas chromatography (GC) and liquid chromatography (LC). High-performance variants such as HPLC or UHPLC operate under high pressure and provide higher resolution.

Typical equipment includes a stationary phase (for example silica or polymeric phases), a mobile phase (solvent or carrier gas), and a detector to monitor eluting components (such as UV–vis, refractive index, or mass spectrometry). Analytical methods combine separation with identification and quantification.

Applications span chemistry, biochemistry, environmental analysis, pharmaceuticals, food and fragrance industries, petrochemicals, and forensics. Limitations include sensitivity to sample preparation, the need for compatible volatility or thermal stability for some modes, and the requirement for appropriate selection of stationary and mobile phases.

History notes: chromatography originated in the early 20th century with Mikhail Tsvet's work; modern developments led to GC and LC, with rapid advances in detectors and columns in the late 20th century.