Figure 9.56
Mass spectrum of benzyl acetate.(Rule 3). The size of the M + 2 peak indicates the absence of sulphur and halogens and the empirical
formula C 9 H 10 O 2 given in Beynon's tables best fits the isotope peak ratios. The number of saturated sites
is 9 + 1 ā 5 = 5, i.e. one ring and four double bonds.
Lastly, Figure 9.57 shows a spectrum of 2-pentanol. The base peak at m/z 45 is due to cleavage at the
CāC bond adjacent to the OH group (Rule 3) and several peaks appear corresponding to the loss of H 2 O
and C 2 H 2 (Rule 4).
Figure 9.57
Mass spectrum of 2-pentanol.Applications of Mass Spectrometry
Used in conjunction with infrared, NMR, UV and visible spectral data, mass spectrometry is an
extremely valuable aid in the identification and structural analysis of organic compounds, and,
independently, as a method of determining relative molecular mass (RMM). The analysis of mixtures
can be accomplished by coupling the technique to GC (p. 114). This was formerly done by using sets of
simultaneous equations and matrix calculations based on mass spectra of the pure components. It is well
suited to gas