Measuring Gas-Phase Basicities of Amino Acids Using an Ion Trap Mass Spectrometer. A Physical Chemistry Laboratory Experiment

2005 ◽  
Vol 82 (7) ◽  
pp. 1071 ◽  
Author(s):  
Victor Ryzhov ◽  
Lee S. Sunderlin ◽  
Lanea M. M. Keller ◽  
Elizabeth R. Gaillard
Keyword(s):  
Physical Chemistry ◽  
Amino Acids ◽  
Laboratory Experiment ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Ion Trap ◽  
Chemistry Laboratory ◽  
Ion Trap Mass Spectrometer ◽  
Gas Phase Basicities

Gas phase attachment of water and methanol to Ag(I) complexes with ?-amino acids in an ion trap mass spectrometer

2001 ◽  
Vol 15 (8) ◽  
pp. 615-622 ◽  
Author(s):  
B. A. Perera ◽  
M. P. Ince ◽  
E. R. Talaty ◽  
M. J. Van Stipdonk
Keyword(s):  
Amino Acids ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Ion Trap ◽  
Ion Trap Mass Spectrometer

Gas Phase Reactions of Trimethylborate with the [M − H]− Ions of Nucleotides and Their Non-Covalent Homo- and Heterodimer Complexes

2003 ◽  
Vol 56 (5) ◽  
pp. 389 ◽  
Author(s):  
Ana K. Vrkic ◽  
Richard A. J. O'Hair
Keyword(s):  
Gas Phase ◽  
Mass Spectrometer ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Methanol Molecule ◽  
Collision Induced Dissociation ◽  
Base Loss ◽  
Gas Phase Reactions ◽  
Ion Trap Mass Spectrometer ◽  
Neutral Base

Trimethylborate (TMB) reacts with deprotonated monomer, homo-, and heterodimer ions of nucleotides (2′-deoxyadenosine-5′-monophosphate [dAMP], 2′-deoxycytidine-5′-monophosphate [dCMP], 2′-deoxyguanosine-5′-monophosphate [dGMP], and 2′-deoxythymidine-5′-monophosphate [dTMP]) in a quadrupole ion trap mass spectrometer by addition with concomitant elimination of one or two methanol molecules (monomers), one or three methanol molecules (homodimers), and three methanol molecules (heterodimers). The mode of reaction appears to influence the observed rates, with the loss of only one methanol molecule corresponding to the fastest rate. There appears to be a structure–reactivity correlation for the monomers, with the [dGMP – H]– ions (which adopt a syn conformation of the guanine moiety) reacting fastest with TMB through the loss of only one methanol molecule. No such structure–reactivity trends are observed for the homo- and heterodimers. In addition, the collision-induced dissociation (CID) reactions of the [(dXMP)n − H]– (n = 1 or 2) as well as the [dXMP + dYMP – H + (CH3O)3B – 3(CH3OH)]– ions (where nucleotides X, Y = A, C, G, or T) were studied. The latter fragment to form [dXMP – H + BPO4]– and [dXMP – 3H + BPO3]– ions (where X = A, C, G, or T), while [dXMP – H]– ions fragment by neutral base loss. The homo- and heterodimers fragment to form [dXMP – H]– and [dXMP + HPO3]– ions, and the relative abundances of the [dXMP – H]– monomer ions from the heterodimers led to the following acidity order: dGMP ≈ dTMP > dCMP > dAMP.

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