Mobilities of amino acid adducts with modifiers in the buffer gas of an ion mobility spectrometer depended on modifier size and modifier–amino acid interaction energy

Shift reagents in ion mobility spectrometry: the effect of the number of interaction sites, size and interaction energies on the mobilities of valinol and ethanolamine

“…[11] However, mobility shifts do not always follow the adducts size trend because they are affected by other factors such as the SR-ion interaction energy, steric hindrance, proton affinities, intramolecular bonds, [6,11,12,20,28] and, as we report here, the number of SR interaction sites, among others. [11] However, mobility shifts do not always follow the adducts size trend because they are affected by other factors such as the SR-ion interaction energy, steric hindrance, proton affinities, intramolecular bonds, [6,11,12,20,28] and, as we report here, the number of SR interaction sites, among others.…”

“…B will be excluded from the following discussion because its mobility shifts were explained above. [6,12] According to this and because the size of the adducts are similar (MEH + ≈ NEH + ; MVH + ≈ NVH + ), the order of mobility shifts should follow the energy order mentioned. [6,12] According to this and because the size of the adducts are similar (MEH + ≈ NEH + ; MVH + ≈ NVH + ), the order of mobility shifts should follow the energy order mentioned.…”

“…Ions of organic or inorganic compounds, elements, particles and whole organisms such as viruses and bacteria can be detected. [6][7][8][9][10][11][12][13] The adducts have different sizes and stabilities, and spend different times inside the drift tube, and this feature may be used to separate ions whose peaks overlap in IMS. [1] Cumeras et al review and compare the current IMS instrumentation, their commercial availability, hyphenated techniques (mainly gas chromatography and mass spectrometry) and the effect of instrumental parameters and sampling conditions in the ion mobility data.…”

“…[1] Cumeras et al review and compare the current IMS instrumentation, their commercial availability, hyphenated techniques (mainly gas chromatography and mass spectrometry) and the effect of instrumental parameters and sampling conditions in the ion mobility data. [12] Finally, we used α-(trifluoromethyl)benzyl alcohol to test SR inductive effects produced by the three fluorine substituents; these substituents hindered the SR ability to adduct to the analytes resulting in small ion mobility shifts. When polar SR are introduced in the buffer gas in IMS, other factors known to affect the mobility of ions in drift gases more polarizable than He, as N 2 , such as the charge of the ion and its distribution, [5] are negligible, and the mobility shifts are mostly determined by the interaction with the polar SR.…”

“…[22] However, Rawat et al in 2015 developed models predicting changes in mobility provided by SR, and compared them with calculated models. [11,12,18,20] In differential mobility spectrometry, more information is found with respect to mobility shifts upon introduction of shift reagents in the buffer gas. [11,12,18,20] In differential mobility spectrometry, more information is found with respect to mobility shifts upon introduction of shift reagents in the buffer gas.…”