Determination of fatty acid methyl esters derived from algaeScenedesmus dimorphusbiomass by GC-MS with one-step esterification of free fatty acids and transesterification of glycerolipids

Abstract

Algae can synthesize, accumulate and store large amounts of lipids in its cells, which holds immense potential as a renewable source of biodiesel. In this work, we have developed and validated a GC-MS method for quantitation of fatty acids and glycerolipids in forms of fatty acid methyl esters derived from algae biomass. Algae Scenedesmus dimorphus dry mass was pulverized by mortar and pestle, then extracted by the modified Folch method and fractionated into free fatty acids and glycerolipids on aminopropyl solid-phase extraction cartridges. Fatty acid methyl esters were produced by an optimized one-step esterification of fatty acids and transesterification of glycerolipids with boron trichloride/methanol. The matrix effect, recoveries and stability of fatty acids and glycerolipids in algal matrix were first evaluated by spiking stable isotopes of pentadecanoic-2,2-d acid and glyceryl tri(hexadecanoate-2,2-d ) as surrogate analytes and tridecanoic-2,2-d acid as internal standard into algal matrix prior to sample extraction. Later, the method was validated in terms of lower limits of quantitation, linear calibration ranges, intra- and inter-assay precision and accuracy using tridecanoic-2,2-d acid as internal standard. The method developed has been applied to the quantitation of fatty acid methyl esters from free fatty acid and glycerolipid fractions of algae Scenedesmus dimorphus.

Automated Trimethyl Sulfonium Hydroxide Derivatization Method for High-Throughput Fatty Acid Profiling by Gas Chromatography–Mass Spectrometry

“…Previously frozen sera and cell pellets were thawed on ice before extraction, and the whole extraction process was performed at 4 °C. The extraction of lipid molecules was accomplished by a modified Folch extraction that utilized HPLC-grade iso-octane as the non-polar phase instead of chloroform [ 24 , 53 ]. For serum samples, 50 μL of serum was combined with 100 μL of 0.9% saline and 200 μL of HPLC-grade methanol, followed by 20 μL of 1N HCl acid.…”

“…Gas chromatography–mass spectrometry (GC–MS) platforms are well established for fatty acid analysis and are widely used in lipidomic and metabolomic research [ 8 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. GC–MS analysis of fatty acids requires the derivatization of these analytes into non-polar derivatives, such as fatty acid methyl esters (FAMEs) [ 29 ].…”

Transesterification method of microalgae biomass to produce fatty acid methyl esters

“…Five FAMEs consisting of C16:0 (palmitic acid methyl ester), C18:0 (stearic acid methyl ester), C18:1 (oleic acid methyl ester), C18:2 (linoleic acid methyl ester) and C18:3 (linolenic acid methyl ester) were used as standard materials. 25 Finally, the amount of FAME was calculated from Eqn (3):…”

Liquid chromatography‐dielectric barrier discharge ionization mass spectrometry for the analysis of neutral lipids of archaeological interest

“…Glycerolipids and sterols analysis, among other neutral hydrophobic lipids, has been an analytical challenge despite their biological relevance [5, 6]. To characterize these species with ESI‐MS, derivatization steps [7–9] and/or the use of modifiers promoting cationization (NH 4 + , Na + , Li + , etc.) [10–12] have been proposed, incurring the latter noticeable ion‐suppression or matrix effects [13, 14].…”

“…To characterize these species with ESI-MS, derivatization steps [7][8][9] and/or the use of modifiers promoting cationization (NH 4 + , Na + , Li + , etc.) [10][11][12] have been proposed, incurring the latter noticeable ion-suppression or matrix effects [13,14].…”