What is the difference between GC-MS and HRMS? Which is better for identification of compounds in a crude extract (mixture of compounds)?
Hi Kumari Uma Mahto ,
The main difference between GC-MS and HRMS is the resolution. HRMS has higher resolution than GC-MS.
For the identification of compounds in a mixture of compounds, the choice of one (or both) depends on the your research question.
Do you know the compounds of interest or not?
If you know them, the first tool is usually sufficient as a targeted analysis; otherwise, the latter is much better for non-targeted analysis.
GC-MS is two component system, HRMS is about MS detector in it, which can be low or high resolution.
Kumari, High reaolution relatea to accuracy of m/z determination. For complex, relatively high molecular componuds the higher accuracy - the better identyfication.
Change keyword of your question as they come form abbrevoations of HRMS but do not relate to the topic.
Regards
GB
The high detection power of the unknown chemical/biochemical composition is defined for HRMS.
GC/MS is cheaper than HRMS, and in a first attempt gives a lot of informations because it is results: 70 eV spectra and retention times allow identification of known compounds through highly documented data bases. This is in part automatized. HRMS can be performed with various ionization modes. HRMS in fact gives a precise m/z value. HRMS m/z of the (quasi)molecular peak (if you can identify it) and its isotopic cluster may give the elemental composition of the analyte (not the structure), which is a useful complement of the identification.
I am sure this has been answered already, but just to make sure, the main difference between these two forms of Mass spectrometry (assuming that the HRMS also has the GC part) is that the MS is generally a low resolution mass spectrometer that can only separate ions of mass/charge ratio of 1 UMA. on the contrary, HRMS is as its name implies an instrument capable of separating or providing masses/charge ratios for ions at the ten thousandth units of mass, so that compounds that appear to have similar nominal masses are in fact different. Another large difference is of course price.
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Column