Journal of Analytical, Bioanalytical and Separation Techniques
comparison of oil extraction methods for algae by NMR and Chromatographic techniques
- 1Illinois Sustainable Technology Center, Prairie Research Institute, University of Illinois, Urbana-Champaign, 1 Hazelwood Dr, Champaign, Illinois, USA
- 2Indian Oil Corporation Ltd; R&D Centre, Faridabad-121006, Haryana, India
- 3Ex-Institute of Metrology, Quality and Technology (INMETRO), Xerem, Rio de Janeiro, Brazil
Sarpal, A.S., Illinois Sustainable Technology Center, Prairie Research Institute, University of Illinois, Urbana-Champaign, 1 Hazelwood Dr, Champaign, Illinois, USA, Tel: 91-9899443336; E-mail: firstname.lastname@example.org>
KeywordsNeutral lipids; NMR; HPLC; IR; GPC; GC; GC-MS; Algal extracts; Biofuel; Microalgae
The present study focuses on identification and compositional characterization of neutral (tri acyl glycerides, TAG; free fatty acids, FFA) and polar (glyco/glycerophospho) lipids, and fatty acid chains constituting these lipids in the cyclohexane, dichloromethane and methanol extracts or algal oils of microalgae biomasses. Algal oils were generated by step wise Accelerated Solvent and Soxhlet extraction methods from six microalgae biomasses (Scenedesmus dimorph, Chlorella vulgaris, Spirulina, SD Flakes, Cyanothece and Chlamydomonas) obtained from commercial sources. The analytical protocol developed based on NMR (300 & 400 MHz)(1H & 13C), IR, GPC, GC-FID and GC-MS techniques has provided authentic quantitative information about the nature of neutral lipids, polar lipids, fatty acid profiles, oxylipins (oxo fatty acids) and hydrocarbons present in the extracts. The analyses of fractions generated by silica column chromatographic separation of solvent extracts have facilitated demarcation of 1H NMR chemical shift regions of functional groups corresponding to neutral and polar lipids. Specifically, α (n-3) and γ (n-6) C18:3 were differentiated in the Spirulina by critical examination of 1H NMR spectral features of algal oils from various biomasses. The comparative results by different analytical techniques have shown that newly developed methods based on ¹H NMR techniques can provide direct and rapid quantitative results of neutral lipids components including poly unsaturated fatty acid/ester (PUFA/PUFE) in the algal oils without prior sample treatment. The neutral lipids results obtained by NMR and GPC show good agreement as compared by linear regression analyses. The results showed that nature and contents of neutral lipids, and fatty acids profile in the extracts were dependent upon the methods of extraction and the polarity index of solvent used for extraction, and specific to types of algae strains. The application of NMR and IR techniques enabled assessment of the solvent extraction efficiency towards extraction of neutral and polar lipids including types of fatty acids constituting these lipids.