Matrikseeffekter

Matrikseeffekter, also known as matrix effects, refer to the phenomenon where the response of an analyte in an analytical measurement is influenced by the presence of other components in the sample matrix. This influence can alter the accuracy and reliability of quantitative results, particularly in techniques like chromatography and mass spectrometry. The matrix itself comprises all the components of the sample other than the analyte of interest.

These effects arise from various interactions. They can be chemical, where other substances react with the analyte or the detection system, or physical, where changes in viscosity or surface tension affect sample introduction or separation. Ionization suppression or enhancement in mass spectrometry is a common example, where co-eluting compounds can interfere with the ionization of the analyte, leading to lower or higher signal intensities. Similarly, in chromatography, matrix components can compete for stationary phase binding sites, affecting retention times and peak shapes.

To mitigate matrikseeffekter, several strategies are employed. Sample preparation techniques such as extraction, filtration, and solid-phase extraction are designed to remove or reduce interfering matrix components. Alternatively, internal standards can be used, which are chemically similar to the analyte and are added to both calibration standards and samples. By measuring the ratio of the analyte signal to the internal standard signal, variations in the measurement process, including those caused by matrix effects, can be compensated for. Method validation procedures typically include assessing the extent of matrix effects to ensure the reliability of analytical results.