LC-MS (LC/MS)is used to determine which substances are in a product. In this technique, the substances from the product are first dissolved in a solvent. Then the different substances are separated. Then the substances are ionized and fragmented. This means that neutral substances are given a charge and the substances/molecules are broken into small pieces. Finally, the fragmented substances are separated by weight and the machine calculates which substances are present in the product based on the measured weights.
In the past 20 years the on-line combination of liquid chromatography (LC) and mass spectrometry (MS) has become a robust and routinely applicable analytical tool. Principles and developments in the instrumentation for LC-MS are reviewed, with special attention for those interfaces that are likely to be the most important in the coming years:
- atmospheric-pressure chemical ionization and particle beam.