Identification and estimation of tocopherols and tocotrienols in vegetable oils using gas chromatography-mass spectrometry

Abstract

GOVIND RAO, PERKINS a fructosan-accumulating species (Smith and Grotelueschen, 1966), was used to evaluate this method for characterizing and quantitizing carbohydrate fractions in forage plants. Data indicated that roots of this species have a relatively high free fructose content. The increasing fructose/glucose (Cf/ Cg) ratio corresponding with decreasing ethanol extractions beginning with the 92.5 % hydrolyzed extraction indicated the presence of fructosans of varying chain lengths and the greatest quantity of fructose was extracted with 60% ethanol. These data corroborate the findings of Smith and Grotelueschen (1966). Fructosans in grasses are reported to be similar to the inulin type found in Compositae, but are thought to occur in chain lengths shorter than 35 fructofuranose residues linked 2:6 and terminated by a sucrose residue (Bacon, 1960; Edleman, 1960). In this experiment, fructose/glucose ratios increased with decreasing ethanol concentration indicating the presence of fructosans with average chain lengths of 1.05 (sucrose) at 92.5% ethanol extraction to 20.6 (inulin) at 0% ethanol extraction, in tall fescue roots.Colorimetric determination of fructose in the presence of glucose can be used advantageously for differentiating these two sugars in plant extracts where they are present in greatest quantities. This method, in combination with the ethanol dilution extractions and acid hydrolyses, allows for routine quantitative description of carbohydrates in plant material, with the exception of starch. Because of the simplicity of this method, it can be used for routine determination of sugar components in forage samples, in particular the fructosan accumulating species. LITERATURE CITED

Some compositional properties of camelina (camelina sativa L. Crantz) seeds and oils

“…Crude palm oil, which is inherently rich in ~-, y-and 8-T3 (7), was also obtained from the Embassy of Malaysia (Washington, DC). HPLC fractions for each isomer were collected and dried; the trimethylsilyl ether (TMS) derivatives were prepared, and the structure of each was confirmed by gas chromatography-mass spectrometry (GC-MS) (8). The GC and MS units were model 5890 (Hewlett-Packard) and model 25 (Kratos, Ramsey, NJ), respectively.…”

Determination of tocopherols and sterols by capillary gas chromatography

“…The two species are commonly determined separately, but when data on both are required it is possible to determine them in the same analysis, since they are both found in the unsaponifiable fraction, have a hydroxyl group, and are separable by gas liquid chromatography (GLC) under similar conditions (1)(2)(3)(4)(5). The two species are commonly determined separately, but when data on both are required it is possible to determine them in the same analysis, since they are both found in the unsaponifiable fraction, have a hydroxyl group, and are separable by gas liquid chromatography (GLC) under similar conditions (1)(2)(3)(4)(5).…”

“…Tocopherols and sterols are among the lipids of nutritional interest that are frequently determined in fats and oils and other foods. The two species are commonly determined separately, but when data on both are required it is possible to determine them in the same analysis, since they are both found in the unsaponifiable fraction, have a hydroxyl group, and are separable by gas liquid chromatography (GLC) under similar conditions (1)(2)(3)(4)(5). Further simplification can be achieved by eliminating any initial purification and relying on the superior separation efficiency of capillary gas chromatography to separate the tocopherols and sterols from each other and from the numerous extraneous compounds.…”

Characterisation of minor components in vegetable oil by comprehensive gas chromatography with dual detection

“…All the compounds were tentatively identified by comparing the experimental mass spectra with commercial libraries (NIST08 and Wiley), freely available mass spectra (http://lipidlibrary.aocs.org), the use of literature (Biedermann, Haase-Aschoff, et al, 2008;Gerst, Ruan, Pang, Wilson, & Schroepfer, 1997;Govind Rao & Perkins, 1972;Li, Beveridge, & Drover, 2007;Mariani & Bellan, 1997, 2001Orzoco-Solano, Ruiz-Jimenez, & Luque de Castro, 2010;Tranchida, Salivo, et al, 2013;Verleyen et al, 2002;Wretensjo & Karlberg, 2002;Xu, Gao, & Sun, 2012), and the support of analytes rational position within informative 2D separation patterns.…”

“…These last compounds were characterised by very characteristic mass spectra with a high molecular ion, namely m/z 482 and 496 for c-and a-tocotrienol, respectively (Govind Rao & Perkins, 1972;Mariani & Bellan, 1997). Both compounds were present in high amounts, namely 116 and 121 mg kg À1 , respectively, and they eluted in the free sterol zone of the chromatogram.…”