masseanalyse

Mass analysis, known in Danish as masseanalyse, is a method in analytical chemistry for determining the mass and composition of chemical species by measuring their mass-to-charge ratio, usually after ionization. A mass spectrometer is the central instrument, consisting of an inlet for the sample, an ion source, a mass analyzer, and a detector. The sample is converted into ions, which are separated in the analyzer according to m/z and then recorded as a mass spectrum.

Common ionization techniques include electrospray ionization (ESI), which creates multiply charged ions from liquids, and Matrix-Assisted Laser Desorption/Ionization (MALDI) for large biomolecules. Other methods include electron impact (EI) and chemical ionization (CI) for gases and vapors. Mass analyzers such as quadrupole, time-of-flight (TOF), ion trap, Orbitrap, and FT-ICR separate ions by m/z, enabling the measurement of precise masses with high resolution. Tandem mass spectrometry (MS/MS) fragments selected ions to provide structural information.

High-resolution mass spectrometry (HRMS) provides accurate masses, enabling determination of elemental compositions. Data interpretation yields molecular weights, formulas, and, with MS/MS, structural clues. Mass analysis is widely used in proteomics, metabolomics, pharmaceuticals, environmental analysis, clinical diagnostics, and polymer science.

Preparation, calibration, and standards are important to ensure accuracy. Limitations include ionization efficiency biases, matrix effects, and the need for appropriate instrumentation and expertise.