kromatogram

A kromatogram is a graphical representation of detector response in chromatography as a function of time (or elution volume). It is produced by chromatographic techniques such as gas chromatography (GC) and liquid chromatography (LC). Peaks on the chromatogram correspond to individual compounds that have been separated by the chromatographic column.

The x-axis typically shows retention time in minutes or elapsed time; the y-axis shows detector response, such as UV-Vis absorbance, fluorescence intensity, refractive index, or ion current in MS-based systems. The area under each peak is proportional to the quantity of the corresponding compound and, with calibration, can be used for quantitative analysis. The position of a peak (retention time) helps identify the compound under given conditions, often with reference standards or libraries.

The quality of a chromatogram depends on separation efficiency, baseline stability, and peak shape. Resolution between adjacent peaks, peak symmetry, and absence of baseline drift are important. Chromatographic performance is influenced by factors such as column chemistry, temperature, mobile phase composition, flow rate, and sample preparation.

In practice, chromatograms are used for qualitative identification, quantitative measurement, impurity profiling, and method development. In MS-based workflows, specialized chromatograms such as total ion chromatograms (TIC) or extracted ion chromatograms (XIC) are common. Misinterpretation can occur from co-eluting compounds, noisy baselines, or peak overlap, which may require peak deconvolution or adjustment of method parameters.