Analysis by liquid chromatography coupled with mass spectrometry (LC-MS / LC-MS/MS)
Liquid chromatography coupled with mass spectrometry (LC-MS) is a high-performance analytical method that enables the extremely precise identification and quantification of organic molecules present in complex matrices, even at trace levels. Widely used for the analysis of residues, impurities, metabolites, and heat-sensitive compounds, LC-MS is becoming an essential technique in the pharmaceutical, cosmetic, food, environmental, and materials industries.
What is LC-MS / LC-MS/MS?
LC -MS (Liquid Chromatography – Mass Spectrometry) is an analytical technique that combines two complementary steps:
- chromatography (HPLC) allows the separation of the components of a liquid sample based on their polarity, solubility, or interactions with the stationary phase.
- Mass spectrometry (MS) then allows the separated molecules detected, identified and quantified exact mass and fragmentation profile .
LC-MS/MS (or tandem MS version adds a controlled ion fragmentation step, offering increased specificity and enhanced sensitivity , particularly useful for complex matrices or compounds at very low concentrations.
How the LC-MS method works
The LC-MS method follows several key steps:
- Sample preparation: dilution, filtration or extraction depending on the matrix.
- Separation by liquid chromatography (HPLC or UHPLC) : the compounds migrate at different speeds through the column, carried by the mobile phase.
- Ionization : the separated compounds are converted into ions in a suitable ionization source (ESI, APCI…).
- Mass spectrometry analysis : ions are sorted by their mass/charge ratio (m/z) in the analyzer.
- Data detection and processing : generation of mass spectra, identification by library or targeted method (MRM/SRM mode in LC-MS/MS).
Technical specifications of the LC-MS
- Detection limits : ng/g to pg/g depending on the compounds
- Types of ionization : ESI (Electrospray Ionization), APCI (Atmospheric Pressure Chemical Ionization)
- Analysis modes : full scan, targeted ion (SIM), multiple reaction monitoring (MRM)
- Qualitative and quantitative analysis
- Very high selectivity and reproducibility
- Associated standards : Ph. Eur., USP <621> and <146>, ICH Q2(R1), ISO, REACH, FCM
For which matrices?
LC -MS / LC-MS/MS is applicable to a wide variety of liquid, solid or complex matrices:
Main industrial applications
LC-MS and LC-MS/MS are widely used in R&D, method validation, quality control and regulatory compliance , particularly in the following sectors:
Léa Géréec
Technical and scientific advisor
