• Injection volume. 300 μL.
• Flow rate. 0.5 mL/min.
3.1.3.4 Analysis of the Blends
The blend components were dissolved in TCB at 130
C. The SEC operating
temperature was also 130
C. The NMR accessory was kept at a temperature of
120 or 130
C. Similar to ambient temperature LC-NMR, specific solvent signals
must be suppressed [54]. The suppression of the three aromatic proton signals of the
solvent was achieved by WET (water suppression through T 1 effects) suppression
without adding a lock solvent. A wide molar mass range (100–1,000,000 g/mol)
was covered by the SEC column set.
Figure 3.7 shows the on-flow run of blend A. Two data sets were generated
comprising the raw data, including the impurities of the solvent in Fig. 3.7a and the
corrected plot by subtracting signals, which correspond to impurities of the solvent
in Fig. 3.7b.
Fig. 3.7 SEC-NMR on-flow
run of blend A at 130
C in
TCB (a) and corrected
on-flow run (b), column set
1 (reprinted from [51] with
permission of Elsevier)
3.1 Multidetector Size Exclusion Chromatography
87