A simultaneous FT-Raman-DSC (SRD) study of polymorphism in sn-1,3-distearoyl-2-oleoylglycerol (SOS)

The simultaneous FT-Raman-differential scanning calorimetry (SRD) technique is described, which allows FT-Raman spectra to be collected from thermally sensitive samples with a very low power density at the sample surface, imm ediately followed by an in situ DSC melting curve. This gives unambiguous c haracterisation of samples which are thermally sensitive or which could be structurally transformed by an incident high power density laser beam. In t he current work, SRD has been applied to a study of the structural polymorp hs of the triglyceride 1,3-distearoyl-2-oleoylglycerol (SOS). SRD analysis shows DSC heating curves with onset melting points and features identifying the polymorphs produced as alpha, gamma, beta', beta(2) and beta(1), confo rming well to literature thermal behaviour. Interpretation of the correspon ding Raman spectra for these polymorphs provides confirmation of existing s tructural models in the literature based on other analytical techniques.