Polyester Columns Research Articles

Analysis of the Fatty Acids from Sei Whale Blubber Oil

While a few reports on the component fatty acids of the baleen whale oils by gas-liquid chromatography (GLC) have been published, no detailed paper including the minor constituents on the antarctic whale oil has been found yet.The purpose is minute examination of the component fatty acid of the antarctic sei whale blubber oil by GLC using a hydrogen flame ionization detector.Two samples of the oil were converted to methyl esters by alkali-catalyzed methanolysis, and the resulting methyl esters were separated by preliminary urea complex fractionation and by subsequent silicic acid column chromatography or thin layer chromatography on silica gel impregnated with silver nitrate. Each fraction was then analyzed by GLC on a polyester column before and after hydrogenation, as previously reported.As a result, qualitative evidence was confirmed for the presence of more than 45 fatty acids ranging from 12 to 24 carbon atoms in chain length. Included were the esters of the following : Normal saturated acids (12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22 C-atoms), branched-chain fatty acids (14, 15, 16, 17 and 18 C-atoms), monoenoic acids (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24 C-atoms), dienoic acids (14, 16, 18 and 20 C-atoms), trienoic acids (16, 18, 20 and 22 C-atoms), polyenoic acids (16 : 4, 17 : 4, 18 : 4, 20 : 4, 22 : 4, 19 : 5, 20 : 5, 21 : 5, 22 : 5, 22 : 6 and 24 : 6), and a large number of unknown minute components.As above mentioned, it is noteworthy that polyunsaturated odd-numbered and branched-chain fatty acids are present in the constituents of sei whale oil.

GAS CHROMATOGRAPHIC STUDY OF FATTY ACID COMPOSITION OF HUMAN SKIN SURFACE FILM LIPID

1) Human skin surface film lipid was obtained by swab method with ether from 75 normal individuals from the newborn to those in the seventies of both sexes.2) Total fatty acid composition was analysed by gas chromatography on a polyester column.3) Variations of composition of fatty acids according to sex, age and parts of the body were analysed.4) Regional differences: -16.00 (palmitic and branched-chain unsaturated C16) and 18.00 (stearic and branched-chain unsaturated C18) acids were higher; 14.00 (myristic) and 16.50 (palmitoleic) acids were lower on the lower extremities than on the other parts of the body.5) Variations by sex. In adults, the male had a higher 16.50 (palmitoleic) acid content, and in adults above 50 years of age, the female had higher 18.00 (stearic and branched-chain unsaturated C18) acid content.6) Variations by age. 14.00 (myristic) and 16.50 (palmitoleic) acids showed changes parallel to the amount of skin surface lipid with some exceptions: they were lower in childhood, and higher after adolescence. The percentages of 18.00 (stearic and branched-chain unsaturated C18) and 18.44 (oleic) acids showed an inverse change by age: they were high in childhood.7) These changes of fatty acid composition of skin surface film lipid can be partly explained, at least, by considering them as the result of a different mixture ratio of lipids from epidermal and sebaceous gland origin.8) It was deduced that myristic and palmitoleic acids mainly originate from the sebaceous gland and oleic acid from the epidermal cells.

Analysis of hydroxy fatty acids by gas-liquid chromatography

Techniques for the gas-liquid chromatographic (GLC) separation of hydroxy fatty acids are described. Procedures are given for GLC of the methyl esters of hydroxy fatty acids from 14–18 carbons, and the acetoxy fatty acid methyl esters from 14–26 carbons. The degree of unsaturation of α-hydroxy fatty acids can be determined by GLC of acetoxy fatty esters on polyester columns. The position of the hydroxyl group on the carbon chain markedly affects retention time, as shown by GLC of hydroxymethylpalmitates with the hydroxyl group in positions 2–16. Procedures are described for the rapid preparation, characterization, and quantitation of saturated and unsaturated 2-acetoxy fatty acid methyl esters ranging from 14–26 carbons encountered in sphingolipids.

A satisfactory glc column for the determination of epoxyoleic acid in seed oils

AbstractA number of stationary phases were evaluated for their suitability for the analysis of methyl epoxyoleate. Ethylene glycol succinate polyester, Carbowax 20M and Apiezon 舠L螇 all showed evidence of decomposition or alteration of the compound and also a loss of area on the chromatogram. A silicone rubber (SE‐30) column did not exhibit this tendency and was found satisfactory for the determination of methyl epoxyoleate.A limitation of the use of an SE‐30 column in the analysis of mixed esters is its inability to separate effectively fatty acid esters of the same chain length. However, by chromatographing the sample on a polyester column as well as on an SE‐30 column, all of the fatty acid components of the oil can be determined quantitatively.

Cod Liver Oil: Component Fatty Acids as Determined by Gas–Liquid Chromatography

The component fatty acids of cod liver oil from a single fish have been determined by gas–liquid chromatography on several polyester columns with identifications by the linear log plot and separation factor procedures. A number of acids have been detected which are not listed in recent comparable studies.

9種の貝の脂肪酸組成について

For analysis of fatty acid composition nine common and marketable species of shellfish were selected in January, 1963, at Tsukiji Wholesale Market, Tokyo. Total sterol content was determined as cholesterol by the Sperry-Schoenheimer modification of the Liebermann-Burchard reaction. An average of 93mg of sterol was found per 100g of viscera-free tissue (Table 1). Fatty acids were analyzed on a gas-chromatograph equipped with a diethylene glycol suc-cinate polyester column (Fig. 1). Table 2 shows the relative retention volumes of standard fatty acids. On chromatograms of samples, three peaks appeared having relative retention volumes of 81.5, 405, and 610. From chromatograms of the urea complex filtrate and unsa-ponifiable matters, these peaks were presumed to be C18 aldehyde, C22:2 and C22:4 fatty acids, respectively (Table 3, Figs. 2 and 3). Although each species of shellfish showed its own pattern of fatty acid composition as shown in Table 4, general aspects of all patterns could be summarized as follows: 1) C15 odd acid was recorded at 2.3-4.9 per cent as much as C14 saturated acid. 2) The level of C16 saturated acid, which was found as the largest component in seven out of the nine samples, was 30 per cent in hen clam and nearly 20 per cent in other samples. Cl8:1 and C22:6 fatty acids, which are often found in large quantities in fish muscle lipids, contributed less than 20 per cent of the total. 3) Among the species tested, top-shell, abalone, and kid-abalone belong to gastropoda and take seaweeds as their food, while six others belong to pelecypoda and are known as plankton feeders. Between these groups, the seaweed feeders had larger amounts of C20:4 and C22:5 fatty acids than the plankton feeders, but in case of C22:6, vise versa.

Purification and partial characterization of sphingomyelin from human plasma

Isolation of pure sphingomyelin from human plasma on a preparative scale is described. Analyses of fatty acids by gas-liquid chromatography on two polar polyester columns indicate the presence of all even- and odd-carbon, saturated fatty acids from C14 to C25 and most of the corresponding monoenoic acids as well. Palmitic acid is the predominant component; seven of the acids constitute over 90% of the total fraction. A previously unassigned trace constituent of the fatty acid fraction has been tentatively identified as a C24 dienoic acid on the basis of relative retention times, microhydrogenation, and reaction with mercuric acetate.

An assay for pentadecylcatechols in poison ivy extracts by gas chromatography

A method for the assay of pentadecylcatechols by gas-liquid chromatography has been developed. The resin to be analyzed is reacted with acetic anhydride to prepare acetylated pentadecylcatechol. Aliquots of the untreated resin and of the acetylated resin are then analyzed in succession using a hydrogen flame ionization detector. The sum of the areas under (1) the peak appearing in the analysis of the acetylated sample with a retention time identical with pentadecylcatechol and either (2) the peak with a retention time on a polyester column slightly longer than pentadecylcatechol or (3) a retention time on a silicone rubber column slightly shorter than pentadecylcatechol are a function of the urushiol present.

The analysis ofCis‐trans fatty acid isomers using gas‐liquid chromatography

AbstractThe geometric isomers of many unsaturated fatty acid methyl esters can be separated using high‐resolution gas‐liquid chromatography on polyester or Apiezon columns. Separations reported for the geometric isomers of monounsaturated, ricinoleic, linoleic, conjugated, and epoxy fatty acids are reviewed here. New data is presented on the resolution of linolenate geometric isomers on both polyester and Apiezon columns. The separation of methyl oleate and methyl elaidate on a polyester column has also been accomplished. Techniques for preparing and using the high‐resolution columns necessary for these separations are reviewed.

Influence of Column Temperature in the Gas-Liquid Chromatographic Separation of Methyl Esters of Fatty Acids on Polyester Substrates

Operation of any polyester column at a given temperature often will not be completely satisfactory for the detection of some of the components present in complex lipid systems. Use of the same column at different temperatures to resolve components known or suspected to be present may in many cases be simpler than the use of two different columns.

Age-related changes in the behavior of diethyleneglycol succinate polyester columns.

SummaryAging of a succinate polyester column at a temperature of 192°C for periods of several weeks, results in progressive changes in retention time for unsaturated methyl fatty acid esters. These changes are reasonably predictable.

Fatty acids of lard. A. Identification by gas‐liquid chromatography

AbstratA fresh commercially rendered lard was separated into its component fatty acids by subjecting the methyl esters to gas‐liquid chromatography on nonpolar and polar columns. The lard methyl esters were first chromatographed on a silicone column. This column achieved separation of the component esters principally on the basis of chain length, and fractions which were represented by a single peak or series of peaks were collected. The collected fractions were then rechromatographed on an ethylene glycol succinate polyester column to separate and identify the saturated and the unsaturated esters. Qualitative evidence was obtained for the presence of 29 fatty acids ranging in chain length from 10 to 20 carbon atoms. Included were the esters of the following: Satrated acids (10,12,14,15,16,17,18,19,20, and 22 C‐atoms), monounsaturated acids (14,16,17,18,19, 20, and 22 C‐atoms), and polyunsturated acids (18蝘2,20蝘2,22蝘2,18蝘3,20蝘3,22蝘3,20蝘4,22蝘4,20蝘5, and 22蝘5).3. Peaks for several additional trace components were also observed.

Analysis of the geometric isomers of methyl linoleate by gas chromatography

AbstractThe four geometric isomers of methyl linoleate have been quantitatively determined by gas chromatography on Apiezon L and DEGS polyester capillary columns. Three peaks were eluted from the Apiezon L column: (a) the 9‐cis, 12‐cis isomer; (b) the 9‐cis, 12‐trans isomer; and (c) the 9‐trans, 12‐cis and 9‐trans, 12‐trans isomers combined. The DEGS polyester column also resolved three peaks: (a) the 9‐trans, 12‐trans isomer; (b) the 9‐cis, 12‐cis and 9‐cis, 12‐trans isomers combined; and (c) the 9‐trans, 12‐cis isomer. Since the separation of isomers was different on each column, the content of each of the four isomers could be determined from the combined results. Quantitative results agreed closely with the per centtrans bonds as determined by infrared analysis.

Fatty acids of cows' milk. A. Techniques employed in supplementing gas‐liquid chromatography for identification of fatty acids

AbstractMilk fat methyl esters were subjected to distillation and silicic acid column chromatography to provide fractions of less complexity for gas‐liquid chromatographic analysis. It was still necessary however to employ supplemental techniques for identification. Chromatograms were obtained with polyester columns of different polarity on all the fractions and necessary reference samples. While many of the components were identified in the usual way by plots of relative retention time versus number of carbon atoms, iodine values for total unsaturation and ultraviolet spectrophotometry for conjugated and nonconjugated polyunsaturated acids were essential for positive identification of some components. Similarly, examination by infrared spectrophotometry confirmed the presence or absence of conjugated diene ascis‐trans, trans‐trans or both. Isolatedtrans or terminal double bonds were also determined in this way. Gas‐liquid chromatograms of some fractions showed incompletely resolved peaks attributable to the presence of methyl esters of odd‐carbon atom, branched‐chain, and unsaturated acids. Hydrogenation and rechromatographing provided more positive determination of the structure of these components. Further confirmation of identity of some peaks on the chromatogram was achieved by collection of the appropriate fractions and examination of the collected material. At least 60 fatty acids were identified, including several not previously reported, such as odd‐numbered carbon chain length monoethenoid acids from C15 to C23.

GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART IV. THE ANALYSIS OF THE VOLATILE OIL OF THE LEAVES OF EASTERN WHITE CEDAR

The complete analysis of the neutral volatile oil of the leaves of Eastern white cedar (Thujaoccidentalis L.) by means of gas–liquid chromatography was attempted. The mixture of terpenes was resolved into 28 monoterpenoid components and the major ones were isolated in 5- to 20-mg amounts. Comparison of infrared spectra and retention times with those of authentic specimens led to the positive identification of d-α-pinene, camphene, sabinene, d-limonene, p-cymene, γ-terpinene, l-fenchone, l-α-thujone, d-isothujone, camphor, and bornyl acetate. α-Thujene, β-pinene, myrcene, 1,8-cineole, terpinolene, and terpinen-4-ol were tentatively identified. The percentage composition of a commercial sample of the oil and of one obtained from a tree grown in Saskatoon was determined. The latter oil contained 7.0 to 7.5% of sesquiterpenoid components, which were resolved into four peaks on polyester columns at 180 °C.

Gas chromatography of some brominated methyl octadecanoates

Summary During gas chromatography on a polyester column, the principal effect of bromine substituents on a fatty ester molecule was to increase the retention time in proportion to the increase in molecular weight. Secondary effects arose from configurational isomerism. Methyl threo-9,10-dibromooactadecanoate was retained longer than the erythro diastereoisomer. The chromatographic difference between diastereoisomers was attributed to a change in dipole moment.

The use of capillary columns for the separation of some closely related positional isomers of methyl linoleate by gas chromatography

The separation of some closely related positional isomers of methyl linoleate by gas chromatography has been achieved. Resolution of these substances on packed polyester columns was relatively poor. Efficient capillary columns made of 25 gauge hypodermic tubing and coated with glutarate ethylene glycol polyester completely separated the Δ 8, 11, Δ 9, 12, Δ 10, 13 and Δ 11, 14 methyl octadecadienoates. Non-polar capillary columns were also capable of resolving these isomers but the overlapping of oleate and linolenate made such columns less applicable for the analysis of complex mixtures.

Gas chromatography of unesterified fatty acids using polyester columns treated with phosphoric acid.

THE gas chromatography of unesterified fatty acids was first reported by James and Martin1, who used a column liquid phase of silicone oil containing 10 per cent stearic acid. Beerthuis et al. 2 extended this work to higher fatty acids (C12 and higher) using silicone oil plus β-anthraquinone carboxylic acid and ‘Apiezon L’ grease as liquid phases. With these systems, considerable tailing of the peak occurs and extremely high column temperatures are required. The association phenomenon of the carboxyl group is responsible for the difficulty of the analysis.

Gas‐liquid chromatography of fatty derivatives. II. Analysis of fatty alcohol mixtures by gas‐liquid chromatography

ConclusionsGas‐liquid chromatography has been shown to be applicable to the analysis of fatty alcohols. Through the use of polyester columns these alcohols have been separated according to chain length and degree of unsaturation. A study has been made of the relationship between peak areas of the chromatograms and the actual weight percentages of the four C18 alcohols found in the fatty alcohols derived from linseed oil. Fatty alcohols, prepared from soybean, linseed, and sperm oil have been prepared and analyzed by the proposed procedure.Craig and Murty (1) have recently reported that polyesters based on succinic acid are preferable for the liquid phase of the chromatographic column to those made from adipic in that they afford a better separation of methyl stearate from methyl oleate. Conversely adipic columns gave a more effective separation of the esters of linolenic and arachidic acids.The application of these polyesters to the analysis of fatty alcohol acetates is expected to improve their separation in a similar fashion, but further work is indicated in the search for a liquid phase that will permit both separations in the minimum time.