Determination Of Unsaturated Fatty Acids Research Articles

Fatty Acid Changes in Nearshore Phytoplankton under Anthropogenic Impact as a Biodiversity Risk Factor for the World’s Deepest Lake Baikal

In this study, we present results on fatty acid analysis of phytoplankton of Lake Baikal, the world’s deepest lake, which differs from other lakes by its oceanic features. Since we used a large-mesh net, the net sample phytoplankton were primarily represented by the large elongated diatom Synedra acus. subsp. radians (Kützing) Skabichevskij. The similar algae composition of net samples of spring season phytoplankton collected at different sites of the lake allows us to compare results of the fatty acid analysis of these samples. The phytoplankton diversity of the sedimentation samples was contrary represented by 32 algae species. There are clear changes in the fatty acid composition of net phytoplankton exposed to anthropogenic impacts of varying intensity. The content of polyunsaturated fatty acids in phytoplankton collected from central stations (pelagic stations at a distance of ~10–30 km from the shoreline) without anthropogenic impact was higher by up to 15% than phytoplankton collected from nearshore stations (littoral stations at a distance of ~0.01–0.05 km from the shoreline) and offshore stations (pelagic stations at a distance of ~3 km from the shoreline). The interlaboratory precision of fatty acid determination of phytoplankton is estimated as ≤10%. We found high content of the lipid peroxidation marker (80–340 μg g−1 of dry weight) in phytoplankton from nearshore and offshore stations with intensive anthropogenic impact. In phytoplankton from central stations, we did not find any lipid peroxidation. Determination of unsaturated fatty acids, coupled with analysis of fatty acid peroxidation products, can be used to evaluate the level of anthropogenic impact in terms of ecological health and biodiversity conservation.

Silver-based polymeric ionic liquid sorbent coatings for solid-phase microextraction: Materials for the selective extraction of unsaturated compounds

A new generation of silver-based polymeric ionic liquid (PIL) sorbent coatings has been developed and applied in solid-phase microextraction (SPME). The new materials are based on ionic liquid monomers formed by cations containing the silver(I) ion coordinated with two 1-vinylimidazole ligands. Up to seven different silver-based PIL sorbent coatings were developed by polymerizing the silver-IL monomer in the presence of either silver bis[(trifluoromethyl)sulfonyl]imide, and/or a dicationic ionic liquid crosslinker. The obtained sorbent coatings were found to possess adequate thermal stability despite the presence of the silver(I) ions. Thermal desorption of the analytes at 175 °C was effectively used without any significant decrease in extraction efficiency. The developed sorbent coatings were used in two different applications: the determination of alkenes/alkynes via headspace SPME and the determination of unsaturated fatty acids using direct-immersion SPME. In the former approach, the silver-based PILs were particularly selective for the determination of unsaturated compounds with terminal double bonds such as 1,5-hexadiene, 2-methyl-1,5-hexadiene, and 1,8-nonadiene. A study of the extraction mechanism of the analytes to the sorbent coating revealed a competitive partitioning of the analytes. In the second approach, the most selective silver-based PILs were applied for the determination of oleic acid, linoleic acid, and linolenic acid. After proper optimization of the method, the coatings were found to be more or as sensitive as the commercial polydimethylsiloxane fiber. Limits of detection between 2.6 and 8.2 μg L−1 in ultrapure water and from 12 to 14 μg L−1 in tap water were obtained for the best silver-based PIL, with relative standard deviations lower than 13% in all cases at a spiked level of 160 μg L−1. Finally, the fiber was effectively applied for the analysis of rinse water from a dairy farm, with adequate detection of the analytes at concentrations between 52 and 179 μg L−1.

PREPARATION, EVALUATION, AND CLINICAL APPLICATION OF SAFFLOWER CREAM AS TOPICAL NUTRITIVE AGENT

Objective: The objective of this study was to formulate and evaluate safflower seeds oil as herbal nutritive skin cream and to study its clinical effect.Methods: After collecting the safflower seeds, the oil was extracted using an expeller or cold pressing. Physical parameters of oil were determined. Determination of unsaturated fatty acids was done by gas-liquid chromatography (GLC). The oil is then placed in an emulsifier to form cream using various additives and all formulas evaluated according to physical properties, PH, and viscosity.All symptoms such as skin damage by sunlight, skin aging, oxidative damage after sunburn or after chemical treatments, all of these conditions have recovered. Statistical data analysis was carried out using Statistical Analysis System, and all recorded data for analysis of variance and least significant difference were at least the significant difference at level 0.01.Results: The results of the GLC analysis indicated that safflower oil contains five different fatty acids, including linoleic acid (56.37%), linolenic acid (15.02%), stearic acid (2.37%), oleic acid (14.83%), and palmitic acid (7.91%).Refractive index values, density, and specific gravity were 1.476, 0.921 g/cm3, and 0.925, respectively.The results of a clinical study showed the effect of safflower cream as an antioxidant which protected the skin in particular from oxidative damage after sunburn and reduced the symptoms of skin aging. This effect was evident in both concentrations 10% and 15% when compared with control.Control response rate, 10% of safflower cream, and 15% of safflower cream were reached to 76%, 85%, and 92% within 2 weeks of treatment, respectively.Conclusion: The study showed the importance of safflower oil as a source of omega-3 and contains various unsaturated fatty acids which act as an antioxidant to restore skin health and aging resistance. This study approved that safflower oil characteristics can make it the main ingredients in the preparation of topical agents for the treatment of various skin problems.

Determination of unsaturated fatty acids with a migrating double bond in complex biological matrices by gas chromatography with flame ionization and mass spectrometry detection

We present the results of determination of unsaturated fatty acids (FAs) in foods of animal origin. It is shown that, in addition to the main component, monounsaturated cis-9-octadecenoic (oleic) acid, other fatty acids may be present in the composition of lipids, depending on the type of raw materials used to prepare the food product. The determination of these acids can significantly vary depending on the presence of impurities and assay conditions. It is demonstrated that gas chromatographic systems with a flame ionization detector, conventionally used for the determination of the fatty acid composition, are useless for the reliable identification of close structural analogues of unsaturated essential fatty acids. The conditions of determination of these compounds with mass spectrometric detection are selected. The effect of the composition of analytes, which were animal ingredients, on the results is discussed. It is shown that the greatest difficulty is the determination of unsaturated fatty acids present in test samples of different aetiologies in amounts not exceeding 0.05–0.1%.

Rapid Determination of Unsaturated Fatty Acids in Vegetable Oil by Raman Spectroscopy and Chemometrics

ABSTRACTThe accuracy for the determination of total monounsaturated and polyunsaturated fatty acids in vegetable oil by Raman spectroscopy was enhanced by spectral wavelength selection with competitive adaptive reweighted sampling to obtain partial least squares models based on a small subset of wavelengths. Wavelengths of 26 and 31 were selected from the 842 original points for the total monounsaturated and polyunsaturated fatty acids, respectively. Compared to full spectral models and four frequently-used variable selection methods, the competitive adaptive reweighted sampling achieved better results. The external correlation coefficients for total monounsaturated fatty acids and polyunsaturated fatty acids were increased to 0.9555 and 0.9963, and root mean square errors of prediction were reduced to 0.0207 and 0.0054. The results indicate that a portable Raman spectrometer using competitive adaptive reweighted sampling with partial least squares may be a promising approach for the determination of unsaturated fatty acids in vegetable oil.

Simple and rapid determination of unsaturated fatty acids in 1 µl of rat plasma by LC-MS/MS.

Deficiency or imbalance of unsaturated fatty acids will promote the pathogenesis of many diseases. In order to monitor the exposure of unsaturated fatty acids, the method based on LC-MS/MS was developed. Standard calibration curves for α-linolenic acid, linoleic acid, palmitoleic acid and oleic acid were linear (r ≥0.99). The intra-and interbatch accuracy (RE%) ranged from -4.5 to 8.6%, while the intra- and interbatch precisions (RSD%) were ≤8.7%. The extraction recovery varied from 85.4 to 99.6%, and no obvious matrix effect was observed. The method offers a simple approach for measuring 4 unsaturated fatty acids in 1 μl rat plasma within 3.95 min.

Rapid Discrimination and Determination of Polyunsaturated Fatty Acid Composition in Marine Oils by FTIR Spectroscopy and Multivariate Data Analysis

A rapid analytical approach for discrimination and quantitative determination of polyunsaturated fatty acid (PUFA) contents, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in a range of oils extracted from marine resources has been developed by using attenuated total reflection Fourier transform infrared spectroscopy and multivariate data analysis. The spectral data were collected without any sample preparation; thus, no chemical preparation was involved, but data were rather processed directly using the developed spectral analysis platform, making it fast, very cost effective, and suitable for routine use in various biotechnological and food research and related industries. Unsupervised pattern recognition techniques, including principal component analysis and unsupervised hierarchical cluster analysis, discriminated the marine oils into groups by correlating similarities and differences in their fatty acid (FA) compositions that corresponded well to the FA profiles obtained from traditional lipid analysis based on gas chromatography (GC). Furthermore, quantitative determination of unsaturated fatty acids, PUFAs, EPA and DHA, by partial least square regression analysis through which calibration models were optimized specifically for each targeted FA, was performed in both known marine oils and totally independent unknown n − 3 oil samples obtained from an actual commercial product in order to provide prospective testing of the developed models towards actual applications. The resultant predicted FAs were achieved at a good accuracy compared to their reference GC values as evidenced through (1) low root mean square error of prediction, (2) good coefficient of determination close to 1 (i.e., R 2≥ 0.96), and (3) the residual predictive deviation values that indicated the predictive power at good and higher levels for all the target FAs.

Application of a Handheld Portable Mid‐Infrared Sensor for Monitoring Oil Oxidative Stability

AbstractThis study evaluated the capabilities of a handheld mid‐infrared (MIR) spectrometer combined with multivariate analysis to characterize oils, monitor chemical processes occurring during oxidation, and to determine fatty acid composition. Vegetable oils (corn, peanut, sunflower, safflower, cottonseed, and canola) were stored at 65 °C for 30 days to accelerate oxidation reactions. Aliquots were drawn at 5 day intervals and analyzed by benchtop and portable handheld mid‐infrared devices (4,000–700 cm−1) and reference methods (IUPAC 2301 [1], 2302 [1]; AOCS Cd 8‐58 [2]; and Shipe 1979 [3]). PLSR and soft independent modeling of class analogy (SIMCA) models were developed for oil classification and estimation of oil stability parameters. Models developed from MIR spectra obtained with a benchtop spectrometer equipped with a 3‐bounce ATR device resulted in superior discriminative performances for classifying oils as compared to those obtained from handheld spectra (single‐bounce ATR). Models developed from reference tests and handheld spectra showed prediction errors (SECV) of 1 meq/kg for peroxide value, 0.09% for acid value and 2% for determination of unsaturated fatty acids in different oils. Spectral regions ~3,012–2,850 cm−1 (C–H stretching bands/shoulders of fatty acids), ~1,740 cm−1 (C=O stretching of esters), and ~1,114 cm−1 (–C–O stretching) were found to be important for prediction. Handheld‐FTIR instruments combined with multivariate‐analysis showed promise for determination of oil quality parameters. Portability and ease‐of‐use makes the handheld device a great alternative to traditional methods.

Comparative analysis of eight esterification methods in the quantitative determination of vegetable oil fatty acid methyl esters (FAME)

The results of the quantitative determination of fatty acid methyl esters of vegetable oils, (soybean, flaxseed, and palm oils) by eight basic and acid catalysis esterification methods were compared. The selected methods were described by Metcalfe, 1966 (MET, ref. 17); Bannon, 1982 (BAN, ref. 18); Joseph and Ackman, 1992 (JAC, ref. 3); Hartman and Lago, 1973 (HLA, ref. 19); Jham, 1982 (JHA, ref. 20); ISO 5509, 1978 (ISO, ref. 21); Bannon, 1982 (BBA, ref. 15) and Schuchardt and Lopes, 1988 (SLO, ref. 22). Despite the large variation in the determination of unsaturated fatty acids, all the methods were efficient in the analysis of saturated fatty acids. The results obtained show that fatty acid analysis may be affected by oil composition and that JAC, ISO, and BBA methods are more efficient. ISO, and BBA are recommended for low acidity samples due to their low reagent toxicity and cost. The JAC method is recommended only for high acidity samples, as the ISO and BBA methods are carried out in basic medium and cannot analyze the free fatty acids.

Structural determination of unsaturated fatty acids in complex mixtures by capillary GC/ MS–MS. Remote site fragmentation of carboxylate anions from electron capture ionization of pentafluorobenzyl esters

Structural determination of unsaturated fatty acids in complex mixtures by capillary GC/ MS–MS. Remote site fragmentation of carboxylate anions from electron capture ionization of pentafluorobenzyl esters

Densitometric determination of unsaturated fatty acids with p‐hydroxybenzaldehyde by HPTLC

AbstractA rapid method for the detection and quantltatlve determlnation of unsaturated fatty acids by TLC is presented. After separation on HPTLC‐RP18‐plates, reaction wlth p‐hydroxybenzaldehyde is carried out by a dipping procedure. Nanogram amounts of unsaturated fatty acids can be determined with good reproducibility.

水産動物肝臓中の脂肪酸について-I

Many studies on the fatty acids of the marine animal livers have been done usually by the distillation of fatty acid esters extracted from high oil content livers. However, little effort has been made for quantitative determination of unsaturated fatty acids in low oil content livers. Kinds of animals used for the present study include bluefin tuna, bigeyed tuna, Indian tuna, Skipjack, fur-seal and fin whale. Free fatty acid and oil were extracted from the livers which had been minced and stored at about -10°C for 1 ?? 2 months. By saponifying the liver oil, mixed fatty acid which had formed glycerid and esters with vitamin A, sterol and other unsaponifiable alcohols, were separated from other components. In order to differentiate two groups of fatty acids, the authors propose to call the former “free type of fatty acids” (FFA) and the latter “ester type of fatty acids” (EFA). On each of the two types of fatty acids, iodine value and neutralisation value were determined (Table 3). Each of them was treated with lead acetate in 95 % alcohol, and separated into solid acid (SA) and liquid acid (LA). After brominated, the latter was separated into four fractions: oleic, linoleic, linolenic and arachidonic acid fractions, by making use of difference of solubility for petrol ether, ether and chloroform (Tables 2 and 4). The results of our experiments were as follows 1. During a long storage, glycerid was destroyed by the lipase in the tissues, but esters of unsaponifiable matters seemed to be hardly attacked by the enzyme (Table 1 and Fig. 1). Then in low oil content livers such as under report, unsaponifiable contents in the extracted oils ran up to 30 ?? 50 % (Table 3). 2. In those fish livers, SA content has been found 22 ?? 27 % in EFA and 24.2 ?? 35.5 % in FFA. The sum of SA and oleic acid was 61 ?? 76 %. Between the two types of FA, percentage of each other unsturated FA was almost the same. Accordingly it may be concluded that a greater portion of FA which forms esters with such unsaponifiable matters as vitamin A and sterols must be composed of oleic acid and SA likewise in glycerid (Table 4). 3. In fin whale, SA was found 41.4 % in FFA and 15.1 % in EFA, whereas in a specimen of fur-seal (B) it was 20.2 %-16.5 % in each type of FA. But the constitution percentages of unsaturated FA of the marine mammals were similar to those of fishes, with the sum of SA and oleic acid being also 61 ?? 76 %. However, the fur-seal (A) had an embryo and exceptionally low content of highly unsaturated FA. Some kinds of vitamins in the liver of fur-seal (A) and (B) were determined (Table 5).

A Note on Increasing the Accuracy of the Micro Alkaline Isomerization Technic for Determination of Unsaturated Fatty Acids

A Note on Increasing the Accuracy of the Micro Alkaline Isomerization Technic for Determination of Unsaturated Fatty Acids