Page 324 - Multidimensional Chromatography

314 Multidimensional Chromatography

Figure 12.9 Typical pyrolysis chromatogram of fraction from a styrene–acrylonitrile
copolymer sample obtained from a microcolumn SEC system: 1, acrylonitrile; 2, styrene.
Conditions: 5 % Phenylmethylsilicone (0.33 m d f ) column (50 m 0.2 mm i.d.); oven tem-
perature, 50 to 240 °C at 10 °C/min; carrier, gas, helium at 60 cm/s; flame-ionization detec-
tion at 320 °C; make-up gas, nitrogen at a rate of 20 mL/min.; ‘P’ indicates the point at which
pyrolysis was made. Reprinted from Analytical Chemistry, 61, H. J. Cortes et al.,
‘Multidimensional chromatography using on-line microcolumn liquid chromatography and
pyrolysis gas chromatography for polymer characterization’, pp. 961–965, copyright 1989,
with permission from the American Chemical Society.

Beypazari, Can and Goynuk lignites was carried out in a conventional Heinze retort.
The pyrolysis product of the Goynuk lignite was analyzed by using coupled
HPLC/GC, with the condensable total oil and tar products from pyrolysis being dis-
solved in dichloromethane. A silica–aminosilane bonded silica column, in series
with a UV detector, a 10-port valve interface with a 150 l sample loop and a Carlo
Erba gas chromatograph equipped with a 25 m 0.33 mm i.d. retention gap, con-
nected to a 25 m 0.33 mm i.d. BP-5 0.5 m analytical fused column, with flame-
ionization detection, was used. The HPLC eluent consisted of 10% dichloromethane
in pentane, with helium being used as the GC carrier gas. After elution of the
aliphatic fraction which contained saturates and olefins, backflusing was carried out
and then analysis of the aromatic fractions was performed. On-line GC of these frac-
tions allowed separation of the components and identification by their retention
indices. It was found that alkanes and alkenes were present in the aliphatic fraction,
and the aromatic fraction contained quantities of polycyclic aromatic compounds
(PACs). In addition, fractionation of the sample by ring size was carried out, with