Page 341 - Multidimensional Chromatography

Industrial and Polymer Applications 331

Figure 12.24 Schematic diagram of the multidimensional packed capillary to open tubular
column SFC–SFC system. Reprinted from Analytical Chemistry, 62, Z. Juvancz et al.,
‘Multidimensional packed capillary coupled to open tubular column supercritical fluid chro-
matography using a valve-switching interface’, pp. 1384–1388, copyright 1990, with permis-
sion from the American Chemical Society.

One of the significant drawbacks of multidimensional analytical methods is the
specificity of the conditions of each separation mode for a particular sample type,
together with restrictive requirements for the type and operational conditions of the
interface between them. Therefore, extensive work in the method development stage,
along with the availability of highly skilled personnel for operating such systems, are
required.
Methods developed for on-line technological control have to be tested for the
variation of the product composition due to process variations. However, if rugged
analytical procedures are developed these multidimensional methods may only
require minimal attention during on-line operation. Multidimensional chromatogra-
phy for the analysis of complex polymer and industrial samples offers chromatogra-
phers high productivity and efficiency and is an excellent alternative to off-line
methods.

REFERENCES

1. R. G. Lichtenthaler and F. Ranfelt, ‘Determination of antioxidants and their transforma-
tion products in polyethylene by high-performance liquid chromatography’,
J. Chromatogr. 149:553–560 (1978).
2. Y. Hirata and Y. Okamoto, ‘Supercritical fluid extraction combined with microcolumn
liquid chromatography for the analysis of polymer additives’, J. Microcolumn Sep. 1:
46–50 (1989).
3. G. Castello, ‘Gas-chromatographic determination of alkyllead compounds in aromatic-
based fuels’, Chim. Ind. 51:700–704 (1969).