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1.
Zhaoyang Luo Chunchun Xia Haojun Fan Xin Chen Biyu Peng 《Journal of the American Oil Chemists' Society》2011,88(7):1029-1036
The biodegradabilities of different oil-based fatliquors derived from rape oil, fish oil, castor oil or mineral oil variants
were investigated by evaluating the respiration curves, BOD5/COD values, COD (chemical oxygen demand) and TOC (total organic carbon) removal ratios. Simultaneously, degradation kinetics
of the fatliquors were also studied. The results indicated that the BOD5/COD values and the COD and TOC removal ratios of all the natural oil based products are higher than 0.45 and 85%, respectively,
implying that all of them are biodegradable. The mineral oil based fatliquors have lower than 0.2 and 10% values, showing
unbiodegradable characteristics and were used as the control. The biodegradability order is castor oil > fish oil > rape oil > mineral
oil product. Further study indicated that the differences in biodegradability result from the varying fatty acid composition
(such as ricinoleic acid and polyunsaturated fatty acids). The higher the active group content, the more beneficial for modification
reactions and result in a higher biodegradation rate. The degradation kinetics studies revealed that the degradation rate
constants (k) of castor oil, fish oil and rape oil products are 0.87, 0.84 and 0.81 d−1 for the sulfated fatliquor, and 0.95, 0.93, 0.85 d−1 for the oxidized–sulfited fatliquors, respectively; indicating that the overall degradation rate followed the same trend
as the biodegradability order where castor oil > fish oil > rape oil, whether the fatliquors underwent modification as sulfated
or oxidized–sulfited. 相似文献
2.
The kinetics of the thermal decomposition reaction of diethylketone triperoxide (3,3,6,6,9,9-hexaethyl-1,2,4,5,7,8-hexaoxacyclononane,
DEKTP) in ethylbenzene solution were studied in the temperature range of 120.0–150.0 °C and at an initial concentration range
of 0.01–0.10 M. This peroxide was used as a new initiator in methyl methacrylate (MMA) polymerization process at high temperatures
(110.0–140.0 °C) in ethylbenzene solution. The effects of initiator concentration and reaction temperature on the polymerization
rate were investigated in detail. Thus, activation parameters of the solution polymerization process (ΔE
d* = 83.3 kJ mol−1 and ΔE
p* − ΔE
t*/2 = 54.0 kJ mol−1) will be obtained. DEKTP can effectively act as initiator in MMA polymerization and its performance is similar to that presented
by a multifunctional initiator resulting in high-molecular weight polymethylmethacrylate with a high reaction rate. 相似文献
3.
Application of arrhenius kinetics to evaluate oxidative stability in vegetable oils by isothermal differential scanning calorimetry 总被引:1,自引:0,他引:1
C. P. Tan Y. B. Che Man J. Selamat M. S. A. Yusoff 《Journal of the American Oil Chemists' Society》2001,78(11):1133-1138
In this study, 10 different vegetable oils were oxidized at four different isothermal temperatures (383, 393, 403, and 413
K) in a differential scanning calorimeter (DSC). The protocol involved oxidizing vegetable oils in a DSC cell with oxygen
flow. A rapid increase in evolved heat was observed with an exothermic heat flow appearing during initiation of the oxidation
reaction. From this resulting exotherm, the onset of oxidation time (T
o) was determined graphically by the DSC instrument. In our experimental data, linear relationships were determined by extrapolation
of the log (T
o) against isothermal temperature. The rates of lipid oxidation were highly correlated with temperature. In addition, based
on the Arrhenius equation and activated complex theory, reaction rate constants (k), activation energies (E
a), activation enthalpies (ΔH
‡), and activation entropies (ΔS
‡) for oxidative stability of vegetable oils were calculated. The E
a′, ΔH
‡, and ΔS
‡ for all vegetable oils ranged from 79 to −104 kJ mol−1, from 76 to −101 kJ mol−1, and from −99 to −20 J K−1 mol−1, respectively. Based on the results obtained, differential scanning calorimetry appears to be a useful new instrumental method
for kinetic analysis of lipid oxidation in vegetable oil. 相似文献
4.
Bleaching kinetics of sunflowerseed oil 总被引:1,自引:0,他引:1
Hüseyin Topallar 《Journal of the American Oil Chemists' Society》1998,75(4):531-533
The bleaching process for sunflowerseed oil follows a rate formula, log (A/A
0)=−κ
, according to absorbance measurements. The dark color of crude oil converts to a light color as the absorbance value decreases.
The activation energy E
a was calculated from the Arrhenius equation as 3 kJ, and other activation thermodynamic parameters were determined as ΔS
⊄=−4.4 J K−1, ΔH
⊄=−31.2 J mol−1, and ΔG
⊄=1.6 kJ mol−1. The study showed that the bleaching process was exothermic, presented a decrease of entropy, and was a nonspontaneous process
during activation. 相似文献
5.
Mohamed M. Ibrahim 《Journal of Inorganic and Organometallic Polymers and Materials》2009,19(4):532-538
A dinuclear zinc(II) complex with the ligand bis{tris[2-(1-methylbenzimidazole-2-yl)ethyl]-methylamine}nitrilotriacetic acid
sodium salt, L, was synthesized and characterized. Complex formation of L with Zn2+ in aqueous acetone was studied by Zn2+ titration using 1H NMR and UV–vis spectroscopies. Analysis of the titration data indicates the formation of a dizinc complex. The νas(COO−) and νs(COO−) stretches were observed at 1572 and 1450 cm−1, respectively. The low separation of the stretches, Δexp = 115 cm−1, is an indication of chelating coordination of the carboxylate group between the two zinc(II) ions. The catalytic activity
of [LZn2]3+
1, as a model for phosphatase that catalyze chemical transformation of phosphate ester, in the hydrolysis of the RNA model, 2-hydroxypropyl p-nitrophenyl phosphate, was examined in aqueous acetone buffer solution, pH 7.0–9.5. The mechanism of the catalytic hydrolysis
suggests that the rate of acceleration is due to what is called double Lewis acid activation. 相似文献
6.
Guang-Xiang Liu Juan Yan Liang-Fang Huang Xiao-Ming Ren 《Journal of Inorganic and Organometallic Polymers and Materials》2009,19(2):243-247
Abstract A new ion-pair complex [1-(4-bromobenzyl)-3-methylpyridinium][Ni(dmit)2] (1), in which dmit = 4,5-dimercapto-1,3-dithiole-2-thione, has been synthesized and structurally characterized. The anions of
[Ni(dmit)2]− stack into dimers, which further construct into a two-leg ladder through lateral S···S interactions. The weak H-bonding interactions
of C–H···S and van de Waals interactions between anion and cations were observed. The magnetic susceptibilities measured from
2–300 K indicate an AFM exchange interaction domination and an AFM ordering below ~8 K. The best fit to magnetic susceptibility
above 40 K, using a dimer model with s = ?, gives rise to Δ/kB = 29.8 K, zJ′ = −0.72 K, C = 3.40 × 10−3 emu K mol−1 and χ
0 = −5.8 × 10−6 emu mol−1 with a fixed g = 2.0. Cyclovoltammetry revealed two quasi-reversible one-electron steps, which are attributed to Ni(IV/III)
and Ni(III/II) redox couples.
Graphical Abstract [A novel complex [1-(4-bromobenzyl)-3-methylpyridinium][Ni(dmit)2] has been synthesized and structurally characterized. The anions of [Ni(dmit)2]− stack into dimers, which further construct into two-leg ladder through lateral S···S interactions. The weak H–bonding interactions
of C–H···S and van de Waals interactions between anion and cations were observed. Moreover, its magnetic property and electrochemical
property have been investigated]
. 相似文献
7.
Fatty Acid Composition,Oxidative Stability,and Radical Scavenging Activity of Vegetable Oil Blends with Coconut Oil 总被引:1,自引:1,他引:0
A. S. Bhatnagar P. K. Prasanth Kumar J. Hemavathy A. G. Gopala Krishna 《Journal of the American Oil Chemists' Society》2009,86(10):991-999
Coconut (Cocos nucifera) contains 55–65% oil, having C12:0 as the major fatty acid. Coconut oil has >90% saturates and is deficient in monounsaturates
(6%), polyunsaturates (1%), and total tocopherols (29 mg/kg). However, coconut oil contains medium chain fatty acids (58%),
which are easily absorbed into the body. Therefore, blends of coconut oil (20–80% incorporation of coconut oil) with other
vegetable oils (i.e. palm, rice bran, sesame, mustard, sunflower, groundnut, safflower, and soybean) were prepared. Consequently,
seven blends prepared for coconut oil consumers contained improved amounts of monounsaturates (8–36%, p < 0.03), polyunsaturates (4–35%, p < 0.03), total tocopherols (111–582 mg/kg, p < 0.02), and 5–33% (p < 0.02) of DPPH (2,2-diphenyl-1-picrylhydrazyl free radicals) scavenging activity. In addition, seven blends prepared for
non-coconut oil consumers contained 11–13% of medium chain fatty acids. Coconut oil + sunflower oil and coconut oil + rice
bran oil blends also exhibited 36.7–89.7% (p < 0.0005) and 66.4–80.5% (p < 0.0313) reductions in peroxide formation in comparison to the individual sunflower oil and rice bran oil, respectively.
It was concluded that blending coconut oil with other vegetable oils provides medium chain fatty acids and oxidative stability
to the blends, while coconut oil will be enriched with polyunsaturates, monounsaturates, natural antioxidants, and a greater
radical scavenging activity. 相似文献
8.
Hui Guo Chen Hu Junqing Qian De Wu 《Journal of the American Oil Chemists' Society》2012,89(2):183-187
A high-performance liquid chromatographic method with an evaporative light-scattering detector has been developed for the
separation and quantitative analysis of four underivatized long chain fatty acids in four different oil matrices. An isocratic
elution mode using methanol/water/acetic acid and an Agilent Eclipse XDB-C18 analytical column was used. Calibration curves
of the four fatty acids (FA) were well correlated (r
2 > 0.999) within the range of 1–10 mg mL−1 for linoleic acid, 0.8–10 mg mL−1 for stearic acid and 0.5–10 mg mL−1 for the other FA. Four oil samples were examined; camellia oil, olive oil, Brucea javanica oil and sesame oil. Good agreement was found with the standard gas chromatographic (GC) method. The proposed method offers
distinct advantages over the official GC method; better separation and precision, and the sample components do not need to
be derivatized. 相似文献
9.
Kinetic Study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical 总被引:1,自引:0,他引:1
Aya Ouchi Masaharu Ishikura Kensuke Konishi Shin-ichi Nagaoka Kazuo Mukai 《Lipids》2009,44(10):935-943
A kinetic study of the prooxidant effect of α-tocopherol was performed. The rates of allylic hydrogen abstraction from various
unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order
rate constants (k
p) obtained are <1 × 10−2 M−1 s−1 for 1, 1.90 × 10−2 M−1 s−1 for 2, 8.33 × 10−2 M−1 s−1 for 3, 1.92 × 10−1 M−1 s−1 for 4, and 2.43 × 10−1 M−1 s−1 for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH2– hydrogen atoms activated by two π-electron systems (–C=C–CH2–C=C–). On the other hand, fatty acid ester 2 has four –CH2– hydrogen atoms activated by a single π-electron system (–CH2–C=C–CH2–). Thus, the rate constants, k
abstr/H, given on an available hydrogen basis are k
p/4 = 4.75 × 10−3 M−1 s−1 for 2, k
p/2 = 4.16 × 10−2 M−1 s−1 for 3, k
p/4 = 4.79 × 10−2 M−1 s−1 for 4, and k
p/6 = 4.05 × 10−2 M−1 s−1 for 5. The k
abstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils, fats, and low-density lipoproteins
may be induced by the above hydrogen abstraction reaction. 相似文献
10.
Cellulase from Penicillium funiculosum was immobilized on functionalized MCF (Meso Cellular Foam) silica by imine bond formation followed by reduction using NaBH4. The specific activities of free and immobilized enzyme were measured for hydrolysis of soluble carboxymethyl cellulose (CMC).
The highest activity of MCF immobilized and native enzyme was obtained at optimum pH 5 and 4.5 respectively. Kinetic parameters,
Michaelis–Menten constant (Km) and maximum reaction velocity (Vmax), were calculated as Km = 0.025 × 10−2 mg/mL, Vmax = 5.327 × 10−3 U/mg for the free enzyme and Km = 0.024 × 10−2 mg/mL, Vmax = 9.794 × 10−3 U/mg for MCF immobilized enzyme respectively. The reusability of immobilized enzymes showed that 66% of its activity is retained
even after 15 cycles. The availability of polar groups (–NH–, –OH) and large pore size of surface modified MCF could be electrostatically
stabilizing the cellulase. Functionalized MCF was found to be a promising material for stabilizing cellulase with 16.4 wt%
loading of enzyme. 相似文献
11.
Lakmali Samuditha K. Dassanayake Dharma R. Kodali S. Ueno K. Sato 《Journal of the American Oil Chemists' Society》2009,86(12):1163-1173
Differential scanning calorimetry (DSC), optical microscopy, and X-ray diffraction (XRD) were used to examine the thermal
behavior, crystal structure, and crystal morphology of rice bran wax (RBX) in bulk and oil–wax mixtures, and to compare them
with those of carnauba wax (CRX) and candellila wax (CLX). The RBX employed in the present study was separated from rice bran
oil by winterization, filtration, refinement, bleaching, and deodorization. The RBX crystals melted in the bulk state at 77–79 °C
with ΔH
melting = 190.5 J/g, which is quite large compared with CLX (129 J/g) and CRX (137.6 J/g). XRD data of the RBX crystals revealed
O⊥ subcell packing and a long spacing value of 6.9 nm. Thin long needle-shaped crystals were observed in the mixtures of RBX
and liquid oils [olive oil and salad oil (canola:soy bean oil = 50:50)]; therefore, the dispersion of RBX crystals in these
liquid oils was much finer than that of CRX and CLX crystals. Organogels formed when the mixture of every plant wax and liquid
oil was melted at elevated temperature and cooled to ambient temperature. However, the mixture of RBX and olive oil at a concentration
ratio of 1:99 wt.% formed an organogel at 20 °C, whereas the lowest concentration necessary for CRX to form an organogel in
olive oil was 4 wt.% and that for CLX was 2 wt.%. Observation of the rate of gel formation using DSC and viscosity measurements
indicated that the gel structure formed soon after RBX crystallized, whereas a time delay was observed between the organogel
formation and wax crystallization of CRX and CLX. These results demonstrate RBX’s good organogel-forming properties, mostly
because of its fine dispersion of long needle like crystals in liquid oil phases. 相似文献
12.
B. Bellal B. Hadjarab N. Benreguia Y. Bessekhouad M. Trari 《Journal of Applied Electrochemistry》2011,41(7):867-872
High quality crednerite CuMnO2 was prepared by solid state reaction at 950 °C under argon flow. The oxide crystallizes in a monoclinically distorted delafossite
structure associated to the static Jahn–Teller (J–T) effect of Mn3+ ion. Thermal analysis showed that it converts reversibly to spinel Cu
x
Mn3−x
O4 at ~420 °C in air and further heating reform the crednerite above 940 °C. CuMnO2 is p-type, narrow semiconductor band gap with a direct optical gap of 1.31 eV. It exhibits a long-term chemical stability in basic
medium (KOH 0.5 M), the semi logarithmic plot gave an exchange current density of 0.2 μA cm−2 and a corrosion potential of ~−0.1 VSCE. The electrochemical oxygen insertion/desinsertion is evidenced from the intensity–potential characteristics. The flat band
potential (V
fb = −0.26 VSCE) and the holes density (N
A
= 5.12 × 1018 cm−3) were determined, respectively, by extrapolating the curve C
−2
versus the potential to the intersection with C
−2
= 0 and from the slope of the Mott–Schottky plot. From photoelectrochemical measurements, the valence band formed from Cu-3d wave function is positioned at 5.24 ± 0.02 eV below vacuum. The Nyquist representation shows straight line in the high frequency
range with an angle of 65° ascribed to Warburg impedance originating from oxygen intercalation and compatible with a system
under mass transfer control. The electrochemical junction is modeled by an equivalent electrical circuit thanks to the Randles
model. 相似文献
13.
Ying Liu Yu-Yong Xu Guang-Xiang Liu Sadafumi Nishihara Xiao-Ming Ren 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(1):177-181
Abstract
A novel anion-radical salt, (Bbzim)(TCNQ)1.5·CH3CN (1), (where Bbzim = 1,3-bis(4-cyanobenzyl)-1H-imidazol-3-ium and TCNQ = 7,7,8,8-tetracyanoquinodimethane) has been fabricated and X-ray single crystal structural analyses. The structure analysis show there exist TCNQ−1 and TCNQ0 entries, which are in agreement with the IR spectra analysis of the compound. Two TCNQ (A) and one TCNQ (B) molecules stack into a triad, and the triads further develop into a column in a pattern ···ABA···ABA··· along a-axis. The temperature dependence of the magnetic susceptibility (2–300 K) for 1 exhibits spin gap of singlet–triplet feature, and the best fit gave the Δ/kB = 1236.5 K. 相似文献14.
Conformational analysis for hydrated ethylene oxide oligomer models by quantum chemical calculations
Hydrate effects on the conformations of ethylene oxide oligomers (EO-x, x = 1–8 mers) were examined using quantum chemical calculations (QCC). Conformational analyses were carried out by RHF/6-31G.
The models were constructed by locating a water molecule to each ether–oxygen in the structures optimized for non-hydrate
oligomers. Hydrate ratio, h (h = H2Omol/Omol in oligomer), was set from 0 to 1.0. The six type conformations with repeated units of O–C, C–C and C–O bonds were examined. Conformational
energy, E
c (HF), was calculated as difference between the energy of oligomer with water molecules and that of non-hydrogen and/or hydrogen
bonding water molecules. Hydrate energies for each conformer, ∆μ
h
(kcal/m.u., based on E
c in non-hydrate state), were negative and linearly decreased with the increase of h values, and such effects with the increase of h values were weaken with increasing x values. These results were consistent with our previous results calculated using the permittivity, ε (ε = 0–80.1), by QCC. In non-hydrate (h = 0), the (ttt)
x
conformers were the most stable independent of x. However, in hydrate states (h = 0.44–0.67), the (tg+t)
x
conformers were the most stable independent of x values, and in h = 1, the (tg+t)8 conformer (8-mer) was most stable [∆E
c(g) = −1.3 kcal/m.u., ∆E
c(g): energy difference between a given oligomer and the (ttt)
x
oligomer]. These results supported the experimental those based on NMR analyses using dimethoxyethane and triglyme solutions.
Molecular lengths (l) of (tg+t)
x
, (tg+g−)
x
and (g+g+g+)
x
conformers having higher x values significantly decreased with increasing h values. Such contraction with hydration, however, was independent of ΔE
c(g) values of each conformer. 相似文献
15.
Vertical distribution of heavy metals in wastewater-irrigated vegetable garden soils of three West African cities 总被引:4,自引:1,他引:3
Nafiu Abdu Aisha Abdulkadir John O. Agbenin Andreas Buerkert 《Nutrient Cycling in Agroecosystems》2011,89(3):387-397
Application of untreated wastewater to irrigate urban vegetable gardens is raising serious concern about possible health risks
associated with the consumption of these vegetables particularly with regard to the concentrations of heavy metals (HM) in
their edible portions. The soil concentrations of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc
(Zn), were investigated in seven vegetable gardens from the three West African cities of Kano (Nigeria), Bobo Dioulasso (Burkina
Faso) and Sikasso (Mali). Also determined were input–output balances of Cd and Zn from five vegetable gardens under 30 years
of wastewater irrigation in Kano. In these gardens Cd (2.3–4.8 mg kg−1) and Zn (13–285 mg kg−1) concentrations throughout the profile attained unsafe levels. The concentrations of Cu (0.8–18 mg kg−1), Cr (1.8–72 mg kg−1), Ni (0–17 mg kg−1) and Pb (0.6–46 mg kg−1) were below the safety thresholds for arable soils. Overall, concentrations of Zn, Cd, Pb and Ni were higher in Kano than
in Bobo-Dioulasso and Sikasso. Input–output analyses in Kano indicated that irrigation wastewater contributed annually 400–3,700 g
Cd ha−1 and 7,200–22,300 g Zn ha−1, fertilizer 30–2,100 g Cd ha−1 50–17,600 g Zn ha−1, harmattan dust 0.02–0.4 g Cd ha−1 and 40–200 g Zn ha−1 while 300–500 g Cd ha−1 and 2,700–4,700 g Zn ha−1 came from rainwater inputs. Input–output calculations subtracting the amounts of HM taken out in vegetable biomass and that
lost to leaching from total inputs yielded an annual net positive balance of 700–4,160 g Cd ha−1 and 9,350–39,700 g Zn ha−1. If such balances remain unchanged for another 10–20 years vegetables raised in these garden fields are likely to be unsuitable
for human consumption. 相似文献
16.
The electrochemical properties of amorphous vanadium pentoxide (V2O5) thin films deposited by reactive r.f.-sputtering were investigated using galvanostatic charge/discharge cycling and galvanostatic
intermittent titration technique (GITT). As x in Li
x
V2O5−y
increased (x = 0–2.0), the electromotive force of the lithium (Li)∣1 M LiClO4–propylene carbonate∣Li
x
V2O5−y
cell decreased gradually without a potential plateau or an abrupt potential reduction, demonstrating that an irreversible
structural change did not occur in the entire Li content. Chemical diffusivity of the Li ion in the Li
x
V2O5−y
thin film measured using GITT was determined to be 4 × 10−13–7 × 10−14 cm2 s−1 in the Li content range investigated. 相似文献
17.
Supercritical fluid extraction is a viable alternative process for extracting oil from olive husk, a residue obtained in the
olive oil production. We analyzed the effects of pressure (P) (100–300 bar), temperature (T) (40–60°C), solvent flow (1–1.5 L/min), and particle size (D) (0.30–0.55 mm) on extraction yield, and three oil-quality parameters: acidity (OA), PV, and phosphorus content (PC). A response
surface methodology based on the statistical analysis of the experimental data permitted us to obtain mathematical expressions
relating the operational variables and parameters studied. At the best extraction condition of the experimental range analyzed
(P=300 bar, T=60°C, D=0.30 mm, and solvent flow=1.25 L/min at standard conditions), the oil yield was 80% (w/w) with respect to hexane extraction,
whereas the quality parameters OA, PV, and PC were 14% (w/w), 8 meq/kg, and 2.3·10−3% (w/w), respectively. These results were compared to those obtained by hexane Soxhlet extraction. The quality of the supercritical
extract was superior, requiring only simple refining. This advantage may result in improved economics of the supercritical
process in relation to the conventional extraction with hexane. 相似文献
18.
Hexane is used to extract edible oils from oleaginous seeds. The detection of hexane in orujo oil is mandatory, as its presence
in the final product may negatively affect human health. Headspace-GC is the technique of choice for determining residual
solvent in foods. In the present work, a new instrument based on the headspace principle and mass spectrometric detection
without chromatographic separation, ChemSensor, is proposed for the direct screening of orujo oil to determine residual hexane.
This instrument provided an overall response, corresponding to the volatiles profile, including that of hexane, which could
not be directly discriminated. By selecting the m/z values corresponding to n-hexane (major component of commercial hexane), the selectivity of the method was good enough to determine residual hexane
in the range of 2.0–65 μg mL−1 (corresponding to 2.3–75.6 mg of hexane per kg of oil) with high precision. The detection limit achieved (0.7 mg per kg of
oil) was lower than the maximum residual limit established by the European Union (5 mg per kg of oil). Two multivariate techniques,
partial least squares and principal components regression (PCR), were compared with univariate regression; PCR provided the
best results. 相似文献
19.
Determination of phospholipids in vegetable oil by fourier transform infrared spectroscopy 总被引:2,自引:0,他引:2
A method was developed to determine the total phospholipid content in vegetable oil by Fourier transform infrared spectroscopy
(FTIR). Calibration curves of I-α-phosphatidylcholine (PC), I-α-phosphatidylethanolamine (PE), and I-α-phosphatidylinositol
(PI) in hexane were generated at different concentrations. The optimal phospholipid absorption bands between 1200–970 cm−1 were identified and used for quantitative determination. High R
2≥0.968 were observed between band areas and phospholipid standard concentrations. Phospholipids from crude soybean oil were
obtained by water degumming, and purification was performed on a silicic acid column. The phospholipid contents of purified
phospholipid extract, degummed and crude soybean oil determined from calibration equations were >90, 0.0113, and 1.77%, respectively.
High correlations of determination (R
2≥0.933) were observed between the FTIR method and thin-layer chromatography-imaging densitometry method for the determination
of phospholipid content. FTIR was found to be a useful analytical tool for simple and rapid quantitative determination of
phospholipids in vegetable oil. 相似文献
20.
Amal A. Hafiz A. M. Badawi F. I. El-Deeb E. A. Soliman M. Y. El-Awady D. E. Mohamed 《Journal of surfactants and detergents》2010,13(2):165-172
A novel series of ferrocenyl surfactants was synthesized by the reaction of ferrocene disulfonic acid with different primary
and tertiary fatty amines to produce the corresponding ammonium salts Fc[SO3
−
+NH3(CH2)
n
CH3]2, where n = 9, 11, or 15 and Fc[SO3− +NH(CH3)2(CH2)
n
CH3]2, where n = 7 or 11, respectively, and where Fc = ferrocene. Chemical structures were confirmed by microelemental analysis, FTIR, and
1H NMR spectroscopy. The critical micelle concentration of each prepared surfactant was determined using equilibrium surface
tension. Furthermore, air/water interface parameters including effectiveness (π
CMC), efficiency (Pc20), maximum surface excess (Гmax), and minimum surface area (A
min) were determined at 30, 40, and 50 °C. Thermodynamic parameters (ΔG°, ΔS°, and ΔH°) for both micellization and adsorption processes were recorded. The new synthesized surfactants were screened as antimicrobial
agents against different bacterial and fungal organisms. 相似文献