Page 321 - Multidimensional Chromatography
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Industrial and Polymer Applications                             311











































                           Figure 12.6 (a) SEC trace of polystyrene PS706 plus additives. (b) Capillary GC trace of the
                           additive fraction: 1, THF (main solvent); 2, n-decane (co-solvent); 3, n-eicosane (internal
                           standard); 4, Tinuvin 327; 5, Cyasorb UV531; 6, Tinuvin 120; 7, Tinuvin 770; 8, Irgafos 168.
                           Reprinted from Proceedings of the 15th International Symposium on Capillary Chromato-
                           graphy, J. Blomberg et al., ‘Automated sample clean-up using on-line coupling of size-exclu-
                           sion chromatography to high resolution gas chromatography’, pp. 837–847, 1993, with
                           permission from Wiley-VCH.


                           concentrations were obtained from both techniques for most of the components, with
                           the exception of Tinuvin 329. A greater concentration was obtained for this additive
                           by using the coupled technique, which may be attributed to additive loss during the
                           precipitation technique. In addition, quantitative results were obtained from ten sep-
                           arate analyses of the sample, with the coupled technique showing a 2–3 times lower
                           %RSD for most of the polycarbonate additives. Typical chromatograms obtained by
                           using this coupled technique are shown in Figure 12.7.
                              Cortes et al. (15) have demonstrated the use of multidimensional chromatography
                           employing on-line coupled microcolumn size exclusion chromatography and
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