By Anonymous on Monday, April 19, 2004 - 12:01 am:
Dear All,
As I am new to MS, I am searching for the differnece in Fragmentation in the case of LCMS and GCMS.
In GCMS, we are observing M+, but in LCMS it is [M+1]+ or some adducts, Is the common fragementation rules applicable only to the ions formed by Electron Impact ionistion (GCMS)?
Kindly give your suggestions...If any referece available please?
Advance thanks
By MG on Monday, April 19, 2004 - 07:19 am:
Regarding the EI fragmentations you are likely to read about in McLafferty, not all of them will translate to LC/MS. In general, the rules for even electron fragmentations will apply. Inductive cleavage is common. I've not found an equivalent book for LC/MS. Do a literature search for CID with electrospray, LC/MS, etc. Most of the papers on fragmentation are specific to a given compound class.
By Anonymous on Monday, April 19, 2004 - 09:25 am:
It is also important to remember that because LCMS forms even electron fragments, the nitrogen rule is reversed--an odd fragment m/z comes from an even number of N.