Hello everyone, I am working on soil and plants metabolomics using LCMS and GCMS. I observed that all procedures for GCMS requires derivatization. Why MUST I derivatize? CANT I RUN GCMS AFTER EXTRACTION DIRECTLY?
Hi Abdulwasiu
In the most cases the compounds need to be derivatized to increase the volatility of highly polar analytes and therefore the sensitivity of your method. Some compounds cannot be detected by GC-MS without derivatization like ethyl glucuronide.
Another reason for derivatization could be to stabilize your analytes. THCA-A for instance is known to decompose to THC and CBD can cyclize to THC under the high temperatures of a GC analysis.
If you use a chiral derivatization reagent, you are able to separate enantiomers which are not separable on an achiral GC column.
Best
Willi
@ Willi Schirmer, thanks for your answer. I appreciate.
How can I know the right reagent to use for derivatization. I am working on soil and plants, can you suggest likely reagents to be used pleaseeeeeee?
I guess that depends on the expected molecules. MSTFA or other silylation reagents work for many functional groups. Might be a good start. If your extraction solvent reacts with MSTFA do a solvent swap of an aliquot. Ethyl acetate works fine with MSTFA
I would also suggest to analyze your extract without derivatization, just for comparison. In the best case you do not even need to derivatize to detect your analytes
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