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1.
Guangqi Zheng Changmo Li Lili Guo Wenliang Ruo Shuo Wang 《Journal of the American Oil Chemists' Society》2012,89(4):561-566
The fatty acid (FA) analysis of microalgae Spirulina was studied by applying accelerated solvent extraction (ASE) and followed by purification using solid-phase extraction (SPE).
The objective was to develop a sensitive and reliable purification procedure to remove pigment in lipids co-extracted from
Spirulina. Four extraction solvents were used for the ASE lipids extraction. The extraction efficiency was ranked in the following
order: chloroform:methanol > dichloromethane:methanol > ethanol > hexane. The major composition of fatty acids were examined.
Hexane and chloroform:methanol were compared for the purification step. The amounts of sorbent (Silica gel H), sample, and
the volume of eluent were optimized during SPE procedure. This purification step can successfully remove the pigments from
extracted lipids. For 0.1 g algae sample, chloroform:methanol (2:1, v/v) was the optimal extraction solvent, 0.3 g silica
gel was the optimal amount of sorbent, with 7 mL for the volume of eluent. For hexane as the extraction solvent, 0.5 g algae
sample, 0.3 g silica gel was the optimal amount of sorbent, 5 mL was the optimal volume of eluent. The calibration curve was
produced comprised from five samples that contained FAME concentrations which was ranged from 0.1 to 10 mg/L (R
2 > 0.99). The recoveries of fatty acids were 67.97–134.37%, 74.20–99.13% and 98.34–115.42%, with standard deviations (SD)
of three replicate detections ranged from 1.09 to 8.41%. 相似文献
2.
Seawater samples collected in the summer of 1989 in Nova Scotia inlets were analyzed for lipid content to examine water quality.
One inlet, the Northwest Arm, is located adjacent to an urban center, while the other, Ship Harbour, is located in an uninhabited
area and contains three commercial mollusk farms. Lipids in the dissolved and particulate fractions were measured by Chromarod-Iatroscan
thin-layer chromatography with flame ionization detection and by gas chromatography. Samples collected near the urban center
had higher levels of particulate hydrocarbons (28±15 μg/L) than those collected in the relatively pristine environment (11±1
μg/L). The urban center samples also had higher levels of particulate free aliphatic alcohols (14±5vs. 8±1 μg/L) and free fatty acids (5±1vs.<0.5 μg/L), suggesting degradation of wax esters and other fatty acid esters. Dissolved and particulate matter fatty acids
contained a higher proportion of monounsaturated acids near the urban center (33–35vs. 25–29% of the total fatty acids). The essential fatty acids 20∶5n−3 (eicosapentaenoic acid) and 22∶6n−3 (docosahexaenoic
acid), presumably of algal origin, were more prominent in the pristine environment (up to 3.5%), where mollusk aquaculture
is practiced. Fatty acid markers of toxic algae were virtually absent (<0.2%) in samples taken from both locations.
O.S.C. contribution 173. 相似文献
3.
Y. C. Mitei J. C. Ngila S. O. Yeboah L. Wessjohann J. Schmidt 《Journal of the American Oil Chemists' Society》2009,86(7):617-625
The phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa-kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal-phase HPLC analysis of the unsaponifiable matter showed that among the
selected oils, the most abundant tocopherol and tocotrienol were γ-tocopherol (2232.99 μg/g) and γ-tocotrienol (246.19 μg/g),
detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g).
Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo oils were 2238.60, 262.40, 246.20,
199.10, and 128.0 μg/g, respectively. GC–MS determination of the relative percentage composition of phytosterols showed 4-desmethylsterols
as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa-kgomo, mkukubuyo, and manketti seed oils,
with β-sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4-dimethylsterols
(45.93%). Besides 4-desmethylsterols (75%), morama oil also contained significant amounts of 4,4-dimethylsterols and 4-monomethylsterols
(15.72% total). GC–MS determination of the absolute amounts of 4-desmethylsterols, after SPE fractionation of the unsaponifiable
matter, confirmed that β-sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being
the richest source (1326.74 μg/g). The analysis showed total 4-desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15,
and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa-kgomo seed oils, respectively. 相似文献
4.
An improved method for the analysis of phospholipids by normal-phase HPLC is described. Addition of methanol and acetonitrile
to a gradient based on 2-propanol/hexane/water promoted a rapid separation of major classes of bovine surfactant phospholipids
(PL) by using a conventional silica column. The use of an ELSD permitted an accurate analysis of a mixture of PL. Calibration
curves were linear within the range of 5–40 μg with detection limits below 1 μg for PE and PC, and CV ranged from 0.6 to 9.6%.
PL present in surfactant homogenates were separated by a solid-phase extraction (SPE) procedure before HPLC analysis. This
methodology gave a recovery of 95% and combined SPE-HPLC and quantification of biological PL within a 30-min run. The use
of ELSD detection of the eluted compounds was precise, linear, and sensitive. 相似文献
5.
A method for quantitative determination of trace amounts of alkylphenol ethoxylates (APE) in environmental water is described.
Levels of 1 to 3 μg/L can be detected and resolved into their complete oligomer distribution (1EO to 18EO) while maintaining
integrity of the oligomer distribution. This is a major improvement over previous methods; for the first time distortion of
oligomer distribution due to work-up conditions of earlier methods has been prevented.
Isolation of the APE from water is achieved using a simple and rapid dual-column procedure. The first column removes interfering
ionic materials, the second traps the APE on alkyl-bonded silica. Assay of the extract employs HPLC with a fluorescence detector.
The method was used for analyzing treated waste-water and river water. A much better picture of the biodegradation behavior
of APE in the environment has emerged as a result of keeping APE oligomer distribution intact during sample extraction. There
is no accumulation of alkylphenol and the low EO oligomers during wastewater treatment, although the oligomer distribution
may become skewed toward these species. Concentrations in the receiving waters examined were very low, in the range of 1–2
μg/L total APE species (OEO to 18EO).
Presented at the 1989 Annual AOCS Meeting in Cincinnati. Ohio. 相似文献
6.
Dewey L. Smith 《Journal of surfactants and detergents》2000,3(4):483-490
Commercial alcohol ethoxylates are composed of a distribution of ethoxymers, and the width of the distribution can affect
some performance properties such as cloth wetting. For example, if the distribution is peaked at the fastest wetting ethoxymer,
wetting time decreases. One can predict if further peaking will significantly improve wetting performance if the relationship
between ethoxymer distribution peaking and wetting can be determined. As a first step in predicting how cloth wetting time
changes with peaking of the ethoxymer distribution, the cloth wetting time of a binary mixture of octaethylene glycol monododecyl
ether (C12−8) and hexaethylene glycol monotetradecyl ether (C14−6) was studied. Wetting time was inversely dependent on the
average diffusion constant of the mixture, which is predicted from the diffusion constants of the ethoxymers in the mixture
and the mixture composition. Diffusion constants of the ethoxymers are derived from dynamic surface tension measurements.
Therefore, it is possible to predict the relative cloth wetting time for any alcohol ethoxylate distribution by knowing the
diffusion constant of each ethoxymer in the distribution and the distribution composition. 相似文献
7.
Sung Dong Lee Guijae Yoo Hee Jeong Chae Man-Jin In Nam-Soon Oh Yoon Kyung Hwang Woo Ik Hwang Dong Chung Kim 《Journal of the American Oil Chemists' Society》2009,86(11):1065-1071
The anticancer activity of ginseng originated mainly from lipid-soluble components. The hexane extract of ginseng marc (HEGM)
showed a potent inhibitory activity on human hepatoma (HepG2, GI50 = 41.7 μg/ml) and breast (MCF-7, GI50 = 54.4 μg/ml) cancer cell proliferation in vitro in a concentration-dependent manner as did the hexane extract of ginseng
(HEG), with GI50 values of 21.1 μg/ml in HepG2 and 41.2 μg/ml in MCF-7. The water extract of ginseng (WEG) possessed a low anticancer activity
against both cancer cell lines, but the hexane-soluble fraction of WEG (HSF/WEG) showed a potent anticancer activity against
HepG2 (GI50 = 38.7 μg/ml) and MCF-7 cells (GI50 = 51.1 μg/ml). The hexane extraction in ginseng was a very promising protocol for the maximum recovery of the anticancer
active components in high concentrations. Also the adoption of hexane extraction after water extraction of ginseng was successful
in the effective utilization of the residual lipid-soluble anticancer active components in ginseng marc. 相似文献
8.
A method is described for the separation and determination of plasma tocopherols by gas liquid chromatography (GLC). Proteins
in 0.1 g samples of plasma were precipitated with ethanol containing a known amount of 5,7-dimethyltocol which served as an
internal standard. Tocopherols were extracted into petroleum ether, purified by thin layer chromatography and analyzed as
trimethylsilyl ethers by gas liquid chromatography (GLC) on 0.5% Apiezon L. Recoveries of α- and γ-tocopherols averaged 100%
and 93%, respectively. The mean total tocopherol content of eight human plasma samples was 8.5 μg/g by GLC and 9.9 μg/g by
a ferric chloride-α,α′-dipyridyl method. The α- and γ-tocopherol contents of 16 human plasma samples ranged from 4.0 to 12.3
μg/g and 0.6 to 2.1 μg/g, respectively. 相似文献
9.
针对某石化公司混合碳四深加工项目中因甲醇水洗塔效率的局限性而导致混合碳四中甲醇含量超标的问题,开发了一种混合微萃取耦合模块化深度聚结分离的碳四脱甲醇的成套技术设备,并在某石化公司现场进行中试侧线实验研究。实验结果表明,该成套设备在进出口压降为5kPa,注水比例为5%,停留时间180s以内:对入口甲醇含量分别为300~400μL/L,1200~1400μL/L和40000~50000μL/L的混合碳四,出口甲醇含量为10~30μL/L、50~100μL/L和4000~5000μL/L;分离效率分别为96%、95%及88%以上。分离迅速且在较宽的操作弹性范围内表现出深度分离甲醇的能力及低压降的特点,表明了该技术在碳四水洗脱甲醇系统中具有良好的适用性,为混合碳四分离甲醇提供了新思路。 相似文献
10.
Vivek K. Bajpai Nguyen Thi Dung Hwa-Jin Suh Sun Chul Kang 《Journal of the American Oil Chemists' Society》2010,87(11):1341-1349
This study was undertaken to assess the antibacterial efficacy of the essential oil and extracts of Cleistocalyx operculatus buds against plant pathogenic bacteria of Xanthomonas spp. The diameter of inhibition zones of oil (1,000 μg/disc) and extracts (1,500 μg/disc) against the tested bacteria were
found in the range of 7–23 mm. The MIC and MBC values of the oil and extracts against the tested Xanthomonas spp. ranged from 31.25–125 to 62.5–250 μg/ml and 125–500 and 250–1,000 μg/ml, respectively. The cell viability study demonstrated
a potential detrimental effect of the oil (1,000 μg/ml) and hexane extract (250 μg/ml) on the tested Xanthomonas spp. Also the oil displayed significant antibacterial effects in vivo against Xoo KX019 and Xsp SK12 conducted on greenhouse-grown oriental melon plants (Cucumis melo L. var. makuwa). The results of this study suggest that C. operculatus-derived essential oil and extracts could be used as natural bactericides in the food and agriculture industries. 相似文献
11.
Josep Serra Bonvehí Arrate Lacalle Gutiérrez 《Journal of the American Oil Chemists' Society》2011,88(9):1387-1395
The purpose of this study was to evaluate the antioxidant activity (AA) of 19 propolis extracts prepared in different solvent
(ethanol and propylene glycol). It was observed that all the samples tested had AA, although results varied considerably between
extracts, i.e. 420–1,430 μmol Trolox/g (ABTS), 108–291 mg ascorbic acid/g (DPPH), and 1,573–4,669 μmol iron++ sulfate/g (FRAP). The ethanol may enhance the potency of the AA, and the correlation coefficient between total phenolic content
(TPC) (200–340 mg/g propolis extracts) and AA was statistically significant. Total flavonoids ranged from 72 to 161 mg/g propolis
extracts. The results indicate that TPC and flavonoids contributed to AA. 相似文献
12.
采用塔式SBR反应器,利用城市污水处理厂剩余污泥作为接种污泥,培养出好氧颗粒污泥。实验结果表明:好氧颗粒污泥的形成分为准备期、形成期和成熟期三个阶段。当原水COD在1 500±100 mg/L范围内波动时,其COD去除率可达93.4%,出水COD稳定,污泥浓度MLSS维持在2.0~4.0 g/L之间,半小时沉降比SV可达15%~20%,沉降性能优异。COD去除效果与污泥体积指数SVI有密切关系,当SVI维持在50~60 mL/g之间时,COD去除率可达90%以上,而当SVI高于100 mL/g,其COD去除率效果不佳,出水COD在400 mg/L以上。未经驯化的颗粒污泥对高浓度镉离子比较敏感,当氯化镉浓度为50 mg/L时,COD去除率仅为36.8%,且SVI迅速增加至112 mL/g,颗粒污泥发生解絮。而当氯化镉浓度低于1.0 mg/L时,对好氧颗粒污泥的影响较小。 相似文献
13.
The examination of samples of various commer-cially available vegetable oils (olive oil, sunflower oil, thistle oil, linseed
oil, plant germ oil, etc.) and of various samples of margarine for the presence of vola-tile N-nitroso-compounds yielded the
following results. By means of the above mentioned procedure (gas liquid chromatography — AFID gas liquid chromatography —
TEA), N-nitrosodimethylamine (NDMA) was found to be present in 21 of 61 dif-ferent samples of vegetable oil, in concentrations
ranging from < 1 μg/kg to 23 μg/kg. 18 samples con-tained N-nitrosodiethylamine (NDEA) in concentra-tions varying between
< 1μg/kg and 27.8 μg/kg. 37 out of 107 different samples of margarine were shown to contain N-nitroso compounds. N-nitroso-dimethylamine
was found to be present in 15 samples. The range of concentrations determined was between < 1 μg/kg and 5.8 μg/kg. 33 samples
con-tained N-nitrosodiethylamine in concentrations varying between < 1 μg/kg and 7.5 μg/kg. 相似文献
14.
G. William Chase Jr. Casimir C. Akoh Ronald R. Eitenmiller 《Journal of the American Oil Chemists' Society》1994,71(11):1273-1276
A high-performance liquid chromatographic method is described to determine the sucrose polyester (SPE) content in seven blends
of cooking oils. Four gel-permeation chromatography (GPC) columns were used in series with an evaporative light scattering
mass detector to separate the SPE from the acylglycerols in the final chromatogram. The SPE fraction was collected off the
GPC column and injected onto a reverse-phase C-18 column for quantitation with sucrose octaacetate as an internal standard
and a gradient of nonaqueous solvents as mobile phase. The chromatograms were interference-free, with only two sharp peaks
appearing. The standards were linear from 500 to 5000 μg/mL with a correlation coefficient of r=0.999. The mean percent recovery
(n=9) and standard deviation were 102±6.7. The detector could detect amounts as low as 5 μg SPE. 相似文献
15.
Larvae of the sawfly Tenthredo zonula are specialized on Hypericum. Whether the sawfly is able to sequester plant metabolites was unknown. Aerial materials of Hypericum perforatum and H. hirsutum, as well as dissected larvae and prepupae of T. zonula, were analyzed by HPLC to determine the presence and content of flavonoid glycosides (rutin, hyperoside, isoquercitrin, and
quercitrin) and naphthodianthrones (pseudohypericin and hypericin). All flavonoid glycosides were detected in both Hypericum species, with hyperoside as major compound in H. perforatum (ca. 1.7 μmol/g fresh weight, FW) and isoquercitrin in H. hirsutum (0.7 μmol/g FW). Naphthodianthrones were present at low concentrations (0.02 μmol/g FW) in the former, and almost undetected
in the latter species. In the body parts (i.e., hemolymph, digestive tract, salivary glands, or miscellaneous organs) of T. zonula, the surveyed compounds were detected more frequently in prepupae than in larvae. The compounds were not present in every
sample, and flavonoid glycosides especially occurred in highly variable amounts, with maximal concentrations of 41 μg rutin/prepupa
in salivary glands, 8 μg hyperoside/prepupa in hemolymph (= 0.36 μmol/g FW), 32 μg isoquercitrin/prepupa in salivary glands,
and 63 μg quercitrin/larva in miscellaneous organs (mainly composed of the integument). We conclude that flavonoid glycosides
are sequestered since they were detected in organs other than the digestive tract of larvae, and because prepupae are a non-feeding
stage. The naphthodianthrone pseudohypericin, but not hypericin, occurred generally in the digestive tract (up to 0.25 μg/larva).
Both naphthodianthrones and related unidentified compounds, but not flavonoid glycosides, were found in the larval excrement.
The highly variable distributions of flavonoid glycosides and naphthodianthrones in T. zonula larvae and prepupae make it difficult to determine the ecological significance of these metabolites. 相似文献
16.
The HLD-NAC model has been used as an “equation of state” to predict the properties of microemulsion (μE) systems formulated
with either anionic or nonionic surfactants. The model uses the concept of the hydrophilic-lipophilic difference (HLD) to
calculate the chemical potential difference of transferring a surfactant from the oil to the aqueous phase; as a function
of formulation variables such as type of surfactant, oil, temperature, electrolyte concentration. The value of HLD is used
as a scaling parameter to calculate the net and average curvatures (NAC) of the surfactant at the water/oil interface. These
curvatures determine the phase volumes, phase transitions, and solubilization capacity of μEs. In this work, the HLD-NAC model
is extended to nonideal surfactant mixtures of anionic and nonionic surfactants. The phase behavior of limonene μEs formulated
with binary mixtures of sodium dihexyl sulfosuccinate with nonionic nonylphenol ethoxylates and alcohol ethoxylates was used
to determine the deviations of the HLD from the ideal mixing behavior. The deviations were fitted using a 2-parameters Margules
equation. The results suggests that the deviations in anionic-rich systems are due to the charge shielding effect of nonionic
surfactants, and in nonionic-rich systems, the deviations seem to be explained by the increase in hydration of the surfactant
headgroups due to the presence of anionic surfactants. When these corrections were used to predict the curvature of dioctyl
sulfosuccinate-dodecyl pentaethylene glycol-heptane μEs, the HLD-NAC model corrected for the nonidealities reproduced not
only the trends but also the actual range of values reported in the literature.
相似文献
Edgar J. AcostaEmail: |
17.
HA-SBR法在中成药废水处理中的应用 总被引:2,自引:0,他引:2
将水解酸化+序批式活性污泥法(HA-SBR)应用于中成药废水处理工程中。运行结果表明,在进水CODcr+1000-3000mg/L、BOD5 400-1200mg/L,SS50-200mg/L和色度150-300倍时,处理后出水可达到DB4426-89二级排放标准,该工艺设备简单、占地少,运行便利,且剩余污泥量少。 相似文献
18.
Sarojini J. K. A. Ubhayasekera Alba Tres Rafael Codony Paresh C. Dutta 《Journal of the American Oil Chemists' Society》2010,87(2):173-184
Chicken is the most widely consumed meat all over the world due to chickens being easy to rear, their fast growth rate and
the meat having good nutritional characteristics. The main objective of this paper was to study the effects of dietary fatty
by-products in low, medium and high levels of oxidized lipids and trans fatty acids (TFAs) on the contents of cholesterol and oxycholesterols in meat, liver, and plasma of chickens. A palm fatty
acid distillate, before and after hydrogenation, and a sunflower–olive oil blend (70/30, v/v) before and after use in a commercial
frying process were used in feeding trials after adding 6% of the fats to the feeds. Highly oxidized lipid and TFA feeds significantly
increased the contents of cholesterol and oxycholesterols in all tissues of chicken (0.01 < p ≤ 0.05). The contents of oxycholesterols in chicken meat, liver and plasma obtained from TFA feeding trials varied between
17 and 48 μg/100 g in meat, 19–42 μg/100 g in liver and 105–126 μg/dL in plasma. In contrast, in the oxidized lipid feeding
trials, oxycholesterols varied between 13 and 75 μg/100 g in meat, 30–58 μg/100 g in liver and 66–209 μg/dL in plasma. Meat
from chickens fed with feeds containing high levels of TFAs or oxidized lipids may contribute to higher ingestion of cholesterol
and oxycholesterols by humans. 相似文献
19.
A method using high-performance liquid chromatography and fluorescence detection is optimized and validated for the determination
of Dowtherm ATM in spiked oleochemicals and edible oils. The samples are directly injected into a reversed-phase C18 column, and Dowtherm
A is detected using a fluorescence detector set at 247 nm excitation and 310 nm emission wavelengths. The simple isocratic
mobile phase used is a mixture of methanol and water (90∶10, vol/vol) at a flow rate of 1 mL/min. The limits of quantitation
are from 0.1 to 0.2 μg/g. Mean recoveries ranged from 93.0 to 116% with reproducibilities of 1.29–3.84%. The procedure provides
a simple, reliable and sensitive method for determining Dowtherm A residue in oleochemicals and edible oils without prior
sample cleanup or extraction. 相似文献
20.
Tomoo Yamamura Tomonori Mori Ki Chul Park Yasuhiko Fujii Hiroshi Tomiyasu 《The Journal of Supercritical Fluids》2009,51(1):43-49
Catalytic reduction gasification in the presence of ruthenium(IV) dioxide (RuO2) in supercritical water was used to decompose intractable biomass. The gasification of model biomass samples (glucose, cellulose, and heterocyclic compounds), and low-purity biomass samples obtained from a paper-recycling facility (paper sludge) and from a sewage treatment plant (sewage sludge) were studied. In clear contrast to another catalysts, the RuO2 catalyst completely gasified cellulose to produce mainly hydrogen, methane, and carbon dioxide under various conditions (e.g., 673 K at 30 MPa and 773 K at 50 MPa). As for heterocyclic compounds, nitrogen compounds did not deactivate the RuO2 catalyst; the gasification of carbazole proceeded completely. Furthermore, paper sludge was almost completely decomposed in supercritical water with RuO2 at 723 K. 相似文献