The system uses the procedures described in AOCS Ce , which is based on triglyceride hydrolysis and reaction with BF3. After methylation, FAMEs are. 1Afyon Kocatepe University, Faculty of Veterinary Medicine, Department of Food Hygiene and Technology, Afyonkarahisar, Turkey. 2Akdeniz University, Faculty. AOCS Official Method Ce, “Preparations of Methyl Esters of Fatty Acids,” , pp . has been cited by the following article: TITLE: Trans Fatty Acid Content.
|Country:||Central African Republic|
|Published (Last):||21 April 2007|
|PDF File Size:||5.63 Mb|
|ePub File Size:||17.74 Mb|
|Price:||Free* [*Free Regsitration Required]|
Page 2 of 2. To investigate key parameters for conversion reactions, solutions of pure FFAs and pure TAGs, as well as mixtures of the two, were used.
AOCS Official Method Ce 2-66 Preparation of Methyl Esters of Fatty Acids
Assembly and conditioning of the column— a Observe the normal precautions for assembling capillary columns—arrangement of the column in the oven supportchoice and assembly of joints leak tightnesspositioning of the ends of the column in the injector and the detector reduction of dead spaces.
Unfortunately, standard methods such as AOCS Official Method Ca 5a 12 are not suitable for small-scale analytical lipid determinations, because they require significant quantities of starting material and conversion reagents, and because they are not capable of discerning the free acids from triglycerides in the sample.
The hexane extracts were dried over fresh anhydrous calcium chloride, filtered via a 0. Determination of efficiency and resolution— a Apply the usual working conditions isothermal or temperature programming to give maximum resolution of C18 signals.
AOCS () Official Method Ce,
Either helium or nitrogen may be suitable as a carrier gas, but these may increase helium elution times with respect to hydrogen. After the desired reaction time was complete, the vials were cooled to room temperature and 1. Essential fatty acid components and antioxidant activities of eight cephalaria species from southwestern Anatolia. Preparation of fatty acid xocs esters for gas-chromatographic analysis of lipids in biological materials.
免费下载 AOCS Official Method Ce Preparation of Methyl Esters of Fatty Acids – WDFXW文档分享网
Reference standards—a mixture of methyl esters of fatty acids see Notes, 4. This was done to assure that any observed FAME recovery differences were a result of incomplete conversion and not due to incomplete hexane extraction, with glyceryl triheptadecanoate used to monitor the completeness of both the esterification reaction and the ease of extraction of the resulting FAMEs, while the methyltridecanoate was used to monitor only the effectiveness of the hexane extraction step for FAME recovery.
Nu Check Prep, Inc. Key parameters that were investigated included: Standard methods such as AOCS Official Method Ce 8 are excellent for small-scale analytical determinations for common fats and oils, but these methods are also unable to separate the individual chemical species that form FAMEs.
Note—Critical pairs or triplets of fatty acid peaks may be formed depending on the stationary phase used, e. The critical importance of identifying sources for renewable fuel has led to the pursuit of oil-producing crops and feedstocks, with increasing pressure to trend away from food-based materials and toward non-edible sources.
Capillary column, with the following general specificat i o n s — c o n s t ructed of fused silica or glass; length 25—30 m or 50—60 m, the length depending on the desired separation; 0.
Recorder—If a recorder curve is to be used to calculate the composition of the mixture analyzed, an electronic recorder of high precision is re q u i re d. Furthermore, only trace amounts of C The aqueous phase was extracted four times with 1. This study was designed to establish a set of reaction parameters and protocol aimed at the selective conversion and determination of free fatty acid in oil mixtures, while allowing the popular and accurate use of GC—FID for analysis and quantitation of FAMEs.
It should be of the split-type or on-column see Notes, 1. Composition of sesame oil samples reacted under selective esterification conditions and full transesterification conditions.
A ratio of 0. Verification of selective reactivity was obtained by performing the conversion reaction on a mixture of pure C In most cases, the lipid or oil yield from the material is among the most important deciding factors for candidacy as a potential fuel feedstock. Some key parameters for the selective esterification reaction pathway that have been identified in the literature 13 and were investigated in aoccs work include reaction temperature, mass of substrate, catalyst load and reaction time.
It should 26-6 compatible with the apparatus used. Preparative separation of quercetin, ombuin and kaempferide from Gynostemma pentaphyllum by high-speed countercurrent chromatography. Selection of optimum operating conditions—The prope rties of effi c i e n cy and perm e ability of cap i l l a ry columns mean that the separation between constituents and duration of aoccs are largely dependent on the flow rate of the carrier gas in the column.
The characteristics of the recorder should be: Likewise, the diglycerides and monoglycerides C Abstract A method for selectively determining both free fatty acids FFA and triacylglycerides TAGs in biological oils was investigated and optimized using gas chromatography after esterification of the target species to their corresponding fatty acid methyl esters FAMEs.
Additional experiments were performed with this sesame oil that was spiked with 0.