Instant Notes: Analytical Chemistry

animals) and of pyrethrin insecticides using field ionization MS. Pharmaceutical

samples such as antibiotics can be studied, but soft ionization techniques may

be needed.

One example of the ability of this combined technique to analyze complex

mixtures is provided by the use of GC-MS for a sample of mineral oil with

over 50 components. Accurate identification of peaks from amounts of solutes

ranging from 5 ng to 200 ng was possible. The pyrolysis of polymers, followed

by separation by gas chromatography and identification by mass spectrometry

(Py-GC-MS) extends the combination to include three distinct techniques.

F3 – Gas chromatography-mass spectrometry 297

100

0

20 40 60 80 100

m/z

120 140 160

29

43

57

71

85

37

(^98113127156)
141
Relative abundance %
Fig. 3. Mass spectrum for the peak at 119 s.