Isotope Ratio Mass Spectrometry (IRMS)
Definition
Specialised MS that measures precise ratios of light stable isotopes (delta values of 2H, 13C, 15N, 18O, 34S) on a continuous-flow combustion or pyrolysis interface.
Related terms
- Atmospheric Pressure Chemical Ionisation (APCI)
- A complementary atmospheric-pressure source that vaporises the LC eluent and uses a corona discharge to ionise a reagent gas, which transfers charge...
- Electrospray Ionisation (ESI)
- A soft atmospheric-pressure ionisation source that sprays the LC eluent through a charged capillary into a heated counter-current gas, producing protonated or...
- Hyphenation
- Online coupling of a separation technique (GC, LC, ICP) with a spectrometric detector (MS, FTIR) so identification happens within the same run....
- ICP Plasma
- Inductively coupled argon plasma at 6,000 to 10,000 K that atomises and ionises samples in ICP-MS, generating singly charged elemental ions for...
- Interface
- The hardware bridge that transfers analyte from the separation stage to the detector while removing the unwanted mobile phase (carrier gas, solvent,...
- Internal Standard / Deuterated Standard
- A chemically similar (often perdeuterated) compound spiked into the sample to correct for matrix effects and ionisation suppression. Standard practice in forensic...
- Jet Separator
- Early GC-MS interface (Ryhage, 1964) that used differential pumping through a nozzle to enrich analyte and bleed helium. Replaced by direct capillary...
Explained in
- Hyphenated Techniques in Forensic Science: GC-MS, LC-MS, IR-MS and ICP-MSSpecialised MS that measures precise ratios of light stable isotopes (delta values of 2H, 13C, 15N, 18O, 34S) on a continuous-flow combustion or pyrolysis inte...