Equipments & Technologies
Equipments & Technologies
Energy-resolved mass spectrometry (ERMS)
General notes.
If you own a mass spectrometer capable of carrying out the collision-induced dissociation (CID) that often called MS/MS, you can obtain a very useful spectrum of energy-resolved mass spectrometry (ERMS). With the ERMS, you will be able to distinguish structurally related ions having same m/z value. The method allows distinguishing ions of structural isomers such as diastereomers in general.
In low-energy collision-induced MS/MS experiments, fragmentation proceeds based on the conversion of kinetic energy of a molecular ion or a trapped ion species into potential energy when they collide with a neutral inert gas molecule, such as helium or argon, providing a series of fragment ions. However, the overall pattern of the MS/MS spectra, some of which can often be distinguished by the human eye, cannot be interpreted beyond the m/z values in general. We know for certain that there are differences in the MS/MS spectra of structurally related compounds, including the factor of height that must reflect the arrangements of atoms and chemical bonds. The cleavage preference reflects the bond energy for closely related structures. In this manner, MS/MS experiments provide qualitative information regarding isomeric structures.
Mass spectrometer capable of performing MS/MS can be used to resolve activation-energy related factor by obtaining a plot of the abundance of precursor and daughter ions versus the amplitude of radio frequency (RF) voltage during the collision-induced dissociation (CID) experiments.
Only the precursor ion is activated under CID conditions when QIT-MS is used. For this reason, we usually obtain ERMS spectra consisting of a series sigmoidal curves. This means that the formed fragment ions does not serve as a precursor for further dissociations. On the other hand, more complex ERMS spectra are generally obtained when the triple quadrupole (TQ)-MS is used, because all the ion species including the product ions are subjected to CID conditions.
Application of the method and Significance.
Quadrupole ion trap (QIT)-MS
•Ions with very similar structures such as diastereomers can be resolved.
•One might be able to discuss the potential energy of the ion species.
•By examining the ratio of precursor to product ions, one can evaluate whether an MS/MS spectrum can be used to compare one in the database. Generally, data obtained on QIT-MS is suitable for the comparison regardless of the CID conditions used. (Caution has to be payed when the matrix assisted laser desorption/ionization (MALDI) was used for the ionization. This may result in the ions with somewhat high energies.)
•Comparison of first ERMS spectrum and an ERMS spectrum of a remaining precursor ion after first CID experiment provide information regarding “purity” of an analyte even in the case that it potentially contains structural isomer.
Triple quadrupole MS
•Ions with very similar structures such as diastereomers can be resolved.
•One might be able to discuss the potential energy of the ion species.
•By performing the arbitrary summations of ion intensities, one can extract MSn data with out insource- or post source-dacay.
References (More papers follows, please watch our research!)
Kanie, O. Kanie, Y. Daikoku, S. Shioiri, Y. Kurimoto, A. Mutsuga,S. Goto, S. Ito, Y. Suzuki, K.
Rapid Commun. Mass Spectrom. 2011, 25, 1617-1624.
Daikoku, S. Widmalm, G. Kanie, O.
Rapid Commun. Mass Spectrom. 2009, 23, 3713-3719.
Kanie, O, Kurimoto, A. Daikoku, S. Mutsuga, S. Kanie, Y. Suzuki, K.
Proc. Jpn Acad. Ser. B, 2009, 85, 204-215.
Daikoku, S. Kurimoto, A. Mutuga, S. Ako, T. Kanemitsu, T. Shioiri, Y. Ohtake, A. Kato, R. Saotome, C. Ohtsuka, I. Koroghi, S. Sarkar, S. K. Tobe, A. Adachi, S. Suzuki, K. Kanie, O.
Carbohydr. Res., 2009, 344, 384-394.
5.Energy-resolved structural details obtained from gangliosides.
Shioiri, Y. Kurimoto, A. Ako, T. Daikoku, S. Ohtake, A. Ishida, H. Kiso, M. Suzuki, K. Kanie, O.
Anal. Chem., 2009, 81, 139-145.
Shioiri, Y. Suzuki, K. Kanie, O.
J. Mass Spectrom., 2008, 43, 1132-1139.
7.Energy-resolved mass spectrometry (ERMS) of oligosaccharide.
Kurimoto, A. Daikoku, S. Kanie, O.
Experimental Glycoscience, Glycobiology, Springer, Ed. Taniguchi, N., 2008, 37-38. <Book chapter>
Suzuki, K. Daikoku, S. Ako, T. Shioiri, Y. Kurimoto, A. Ohtake, A. Sarkar, S. K. Kanie, O.
Anal. Chem., 2007, 79, 9022-9029.
Daikoku, S. Ako, T. Kato, R. Ohtsuka, I. Kanie, O.
J. Am. Soc. Mass Spectrom., 2007, 18, 1873-1879.
Kurimoto, A. Kanie, O.
Rapid Commun. Mass Spectrom., 2007, 21, 2770-2778.
Daikoku, S. Ako, T. Kurimoto, A. Kanie, O.
J. Mass Spectrom., 2007, 42, 714-723.
Kurimoto, A. Daikoku, S. Mutsuga, S. Kanie, O.
Anal. Chem., 2006, 78, 3461-3466.
2010/10/20