Supercritical fluid extraction and chromatography and mass spectrometry studies of biopolymers

Supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) are used to study the presence of additives in polymers that are used in living systems. Representative samples are used to illustrate and develop the extraction capability of the system with extracts being analysed both by on-line and off-line SFC, gas chromatography-mass spectrometry (GC-MS), and gravimetrically. Different types of additives are employed illustrating their chromatographic behaviour and the uses of both flame ionisation (FID) and UV /Visible detection. The qualitative aspects of the analysis of polymer additives are augmented by on-line linking of a mass spectrometer (MS) to the SFC. The spectra obtained from this system are compared with other probe-MS, GC-MS and library spectra that are available to establish the quality of the spectra obtained. The development of on-line SFE-SFC-MS for the analysis of polymer additives allows for a quick qualitative analysis of the compounds present in polymer samples. Using a set of flame retardants, which are difficult to analyse by comparable methods, on-line SFE-SFC quantitative investigations are performed on polyurethane foams containing these compounds using short extraction times and varying pressures. The results are compared with the Soxhlet extracts and off-line SFE-SFC analysis of the same samples. An extraction model is used to explain the pattern of extraction of additives from both polyurethane foams and laboratory prepared polyvinyl chloride formulations. The studies are performed using different mobile phase strengths and particle sizes to establish the processes involved. The extracts are analysed quantitatively by SFC-FID and GC-FID.