Determination of lipid content of oleaginous microalgal biomass by NMR spectroscopic and GC–MS techniques
- 915 Downloads
Direct methods based on 1H NMR spectroscopic techniques have been developed for the determination of neutral lipids (triglycerides and free fatty acids) and polar lipids (glyceroglycolipids/phospholipids) in the solvent extracts of oleaginous microalgal biomasses cultivated on a laboratory scale with two species in different media. The chemical shift assignments observed in the 1H and 13C NMR spectra corresponding to unsaturated (C18:N, N = 1–3, C20:3, C20:5, C22:6, epoxy) and saturated (C14–C18) fatty acid ester components in a complex matrix involving overlapped resonances have been unambiguously confirmed by the application of 2D NMR spectroscopy (total correlation spectroscopy and heteronuclear single quantum coherence–total correlation spectroscopy). The study of the effect of a polar lipid matrix on the determination of neutral lipids by an internal reference blending process by a systematic designed experimental protocol has provided absolute quantification. The fatty acid composition of algal extracts was found to be similar to that of vegetable oils containing saturated (C16–C18:0) and unsaturated (C18:N, N = 1–3, C20:N, N = 3–4, C22:6) fatty acids as confirmed by NMR spectroscopy and gas chromatography–mass spectrometry analyses. The NMR methods developed offer great potential for rapid screening of algal strains for generation of algal biomass with the desired lipid content, quality, and potential for biodiesel and value-added polyunsaturated fatty acids in view of the cost economics of the overall cost of generation of the biomass.
Keywords1H and 13C NMR Algal biomass solvent extracts Neutral lipids Triglycerides Biofuel Fatty acids
We sincerely thank INMETRO, Brazil, for conducting this research, which is of national importance to Brazil in view of the development of fuels from sustainable resources. We are thank the Instituto Nacional de Tecnologia for collaboration in the project. We also express our thanks and gratitude to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the grant of a fellowship.
- 4.Mercer P, Armenta RE (2011) Development in oil extraction from micro algae. Eur J Lipid Sci Technol 21:1–9Google Scholar
- 8.Sarpal AS, Silva PRM (2013) Analytical strategies for determining biodiesel potential of algae. http://www.stle.org/resources/articledetails.aspx?did=1755
- 10.Kumar R, Bansal V, Patel MB, Sarpal AS (2012) NMR determination of iodine value in biodiesel produced from algal and vegetable oils. Energy Fuels 26:7005–7008Google Scholar
- 14.Sarpal AS, Kapur GS, Mukherjee S, Jayparkash KC, Jain SK (1995) Determination of iodine value of lubricating oils by NMR spectroscopy. Lubr Eng 51(3):209–214Google Scholar
- 17.Pratoomyot J, Srivilas P, Noiraksar T (2005) Fatty acids composition of 10 microalgal species. Songklanakarin J Sci Technol 27(6):1179–1187Google Scholar
- 21.Jones J, Manning S, Montoya M, Keller K, Poenie M (2012) Extraction of algal lipids and their analysis by HPLC and mass spectrometry. J Am Oil Chem Soc 89:1371–1381Google Scholar
- 22.Sarpal AS, Silva PRM, Cunha VS, Daroda, RJ (2013) Monitoring of biodiesel quality parameters by 1HNMR spectroscopic techniques. http://www.stle.org/resources/articledetails.aspx?did=1836
- 25.Kumar R, Bansal V, Patel MB, Sarpal AS (2014) Compositional analysis of algal biomass in a nuclear magnetic resonance (NMR) tube. J Algal Biomass Util 5(3):36–45Google Scholar
- 31.Algae Biomass Organization (2014) Industrial algae measurements, version 6.0. http://www.algaebiomass.org/wp-content/gallery/2012-algae-biomass-summit/2010/06/IAM-6.0.pdf
- 37.Guillard RRL, Lorenzen CJ (1972) Yellow-green algae with chlorophyllide c. J Phycol 8:10–14Google Scholar