Size exclusion chromatography with UV detection coupled to on-line 1H-NMR and on-line collection via a dedicated interface for subsequent off-line FT-IR

The coupling of size exclusion chromatography (SEC) to on-line NMR spectroscopy and a dedicated interface for the collection of the chromatographic eluent for subsequent FT-IR has been investigated using a number of polymer additives as model compounds. SEC was performed using deuterated chloroform as eluent with the separation monitored on-line by UV detection at 254 nm and on-flow 1H-NMR. The effluent from the NMR probe was directed to a dedicated HPLC/FT-IR interface where it was deposited on a germanium plate. FT-NMR and FT-IR spectra were successfully obtained for 2,6-di-tert-butyl-4-methylphenol (BHT), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) and di-iso-octylphthalate.