Instant Notes: Analytical Chemistry

While these three examples are relatively simple, they illustrate the advantages

of the multidisciplinary approach in the analysis of molecular spectra. However,

caution should always be excercised for two important reasons.

● Aromatic systems other than benzene are widely distributed. Many natural

products contain heterocyclic aromatic rings containing nitrogen, oxygen or

sulfur and these should be included as possibilities in the interpretation of

spectra. Correlation tables for such compounds are contained in the further

reading.

● While spectrometry is very powerful in identifying pure compounds, it often

fails when the sample is a mixture. The following topics in this section

discuss how mixtures may be separated prior to spectrometric analysis.

F2 – Sample identification using multiple spectrometric techniques 293

4000 3000 2000 1500 1000 500

%T

cm–1

(a)

Fig. 3. Example 3.

100

50

(^004080120)
m/z
160 200
Relative abundance
(b)
125/127
160/162/164 M+•
1098765
δ (ppm)
43210
(c)
200 150 100
δ (ppm)
50 0
(d)
Solvent