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101.
Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO2) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers.For the flavour removal test, two types of multilayer films were prepared, DLC/TiO2 films and DLC/TiO2/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO2-coated and the DLC/TiO2/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO2/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO2/DLC film had a photocatalytic effect even though the TiO2 film was covered with the DLC film. 相似文献
102.
V. A. Davankov L. A. Onuchak S. Yu. Kudryashov Yu. I. Arutyunov 《Chromatographia》1999,49(7-8):449-453
Summary A systematic derivation of corresponding equations shows that averaging the pressure and the flow rate of the mobile phase
in a gas chromatographic column over the column length and over the time that an unretained component resides in the column,
requires the use of three different compressibility correction factors,j
2
1
,j
3
2
, andj
4
3
. When multiplied by the adjusted retention volume,V
R-VM, the Martin and James mobile phase compressibility correction factorj
3
2
, only, produces the value of specific retention volume,V
g
T
, which is connected unambiguously with the thermodynamic phase distribution coefficient,K, of the sorbate. 相似文献
103.
Anna Waszkielewicz Natalia Szkaradek Elżbieta Pękala Fabiola Galzarano Henryk Marona 《Biomedical chromatography : BMC》2010,24(12):1365-1372
A series of new (phenoxyethyl)aminoalkanol derivatives were synthesized and evaluated for their anticonvulsant activity. The most promising compound seemed to be (R,S)‐1N‐[(2,6‐dimethyl)phenoxyethyl]amino‐2‐butanol, which displayed anti‐MES activity (in mice, i.p.) with protective index (TD50/ED50) of 5.712, corresponding to that of phenytoin (6.6), carbamazepine (4.9) and valproate (1.7). The lipophilicity of compounds 1–17 exhibiting anticonvulsant activity was investigated. Their lipophilicities (RM0) were determined using reversed‐phase thin‐layer chromatography (RP‐TLC) with a mixture of acetone and water as mobile phases. The partition coefficients of 1–17 (logP) were also calculated using two computer programs (Pallas and ALOGPS) and compared with RM0. The relationship between anticonvulsant activity and lipophilicity of the tested substances was estimated. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
104.
Summary Linear correlation between the major physico-chemical properties of glycols and their relative retention volumes measured
by gas-solid (GSC) and gas-liquid (GLC) chromatography is shown. The coefficients of the linear regression equations describing
the relationship between the relative retention volumes and the physico-chemical parameters (boiling point, density, etc.)
are given. The values of the change in the free energy for the stationary phases studied are given as well as the increments
of this change per −CH2- and CH3-group. The main factors determining the retention of branched glycols on Polysorb, Tween and poly(ethylene glycol) are shown
to be the distance between the hydroxyl groups in their molecules, the presence of alkyl substituents and the type and the
number of these substituents. 相似文献
105.
通过乙酸乙烯酯/顺丁烯二酸酐(VM)共聚树脂的碱解,制备了水溶性的碱解VM树脂(AVM).用CaCl2将AVM水溶与蒙脱石水悬浮体共凝胶,制备了AVM/蒙脱石复合材料.吸水性和保水性测试结果证示:当CaCl2用量为10%,蒙脱石用量为15%时,复合材料的吸水性和保水性最好.粒度测试结果表示蒙脱石在水中的粒径为0.75μm,属于超微细分散.SEM照片显示,AVM/蒙脱石复合材料具有疏松的凝胶结构. 相似文献
106.
107.
《Journal of separation science》2017,40(7):1434-1448
The amount of water adsorbed on polar columns plays important role in hydrophilic interaction liquid chromatography. It may strongly differ for the individual types of polar columns used in this separation mode. We measured adsorption isotherms of water on an amide and three diol‐bonded stationary phases that differ in the chemistry of the bonded ligands and properties of the silica gel support. We studied the effects of the adsorbed water on the retention of aromatic carboxylic acids, flavonoids, benzoic acid derivatives, nucleic bases, and nucleosides in aqueous‐acetonitrile mobile phases over the full composition range. The graphs of the retention factors versus the volume fraction of water in mobile phase show “U‐profile” characteristic of a dual hydrophilic interaction–reversed phase retention mechanism. The minimum on the graph that marks the changing retention mechanism depends on the amount of adsorbed water. The linear solvation energy relationship model suggests that the retention in the hydrophilic interaction liquid chromatography mode is controlled mainly by proton–donor interactions in the stationary phase, depending on the column type. Finally, the accuracy of hydrophilic interaction liquid chromatography gradient prediction improves for columns that show a high water adsorption. 相似文献
108.
M.A. Bees 《Applied Scientific Research》1997,59(2-3):141-158
A deterministic mechanism for the production of plankton patches within a typical medium scale oceanic structure is proposed and investigated. By direct numerical simulation of a simple model of Langmuir circulation we quantify the effects of unsteady flows on planktonic communities and demonstrate their importance. Two qualitatively different zones within the flow are identified: chaotic regions that help to spread plankton and locally coherent regions, that do not mix with the chaotic regions and which persist for long periods of time. The relative importance of these regions to both phytoplankton and zooplankton is investigated, taking into account variations in plankton buoyancy. In particular, species-specific retention zone structure is discussed in relation to variations in environmental forcing. 相似文献
109.
110.
Zhao Y Zhang J Wang B Kim SH Fang A Bogdanov B Zhou Z McClain C Zhang X 《Journal of chromatography. A》2011,1218(18):2577-2583
A method was developed to calculate the second dimension retention index of comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOF-MS) data using n-alkanes as reference compounds. The retention times of the C(7)-C(31) alkanes acquired during 24 isothermal experiments cover the 0-6s retention time area in the second dimension retention time space, which makes it possible to calculate the retention indices of target compounds from the corresponding retention time values without the extension of the retention space of the reference compounds. An empirical function was proposed to show the relationship among the second dimension retention time, the temperature of the second dimension column, and the carbon number of the n-alkanes. The proposed function is able to extend the second dimension retention time beyond the reference n-alkanes by increasing the carbon number. The extension of carbon numbers in reference n-alkanes up to two more carbon atoms introduces <10 retention index units (iu) of deviation. The effectiveness of using the proposed method was demonstrated by analyzing a mixture of compound standards in temperature programmed experiments using 6 different initial column temperatures. The standard deviation of the calculated retention index values of the compound standards fluctuated from 1 to 12 iu with a mean standard deviation of 5 iu. 相似文献