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1.
Summary
l-Phenylalanine was immobilized on nylon membranes with two pore diameters (0.45 μm and 1 μm), by activation with 1,4-butanediol
diglycidyl ether, and the effect of pore size on the affinity adsorption of γ-globulin studied by batch and kinetic methods.
Experiment shows that adsorption on both affinity membranes obeys the Freundlich model. The accessible pore volume for adsorption
of proteins on the membrane with 0.45 μm diameter pores is less than for that with 1 μm diameter pores. The adsorption capacity
of affinity membranes with 1 μm diameter pores is 2.5-fold that of membranes with 0.45 μm diameter pores. Feed-rate has a
larger effect on affinity adsorption on the membrane with 0.45 μm diameter pores than on that with 1 μm diameter pores. Small
pores on the affinity membrane do not cause broadening of the elution peak. It is concluded that affinity interaction and
separation occur mainly in the large pores, and small pore size does not favor improvement of adsorption capacity. γ-Globulin
85.1% pure can be obtained in one step from human plasma by use of the affinity membrane with 0.45 μm diameter pores. 相似文献
2.
Paper-based microfluidic devices for analysis of clinically relevant analytes present in urine and saliva 总被引:3,自引:0,他引:3
Scott A. Klasner Alexander K. Price Kurt W. Hoeman Rashaun S. Wilson Kayla J. Bell Christopher T. Culbertson 《Analytical and bioanalytical chemistry》2010,397(5):1821-1829
We report the use of paper-based microfluidic devices fabricated from a novel polymer blend for the monitoring of urinary
ketones, glucose, and salivary nitrite. Paper-based devices were fabricated via photolithography in less than 3 min and were
immediately ready for use for these diagnostically relevant assays. Patterned channels on filter paper as small as 90 μm wide
with barriers as narrow as 250 μm could be reliably patterned to permit and block fluid wicking, respectively. Colorimetric
assays for ketones and nitrite were adapted from the dipstick format to this paper microfluidic chip for the quantification
of acetoacetate in artificial urine, as well as nitrite in artificial saliva. Glucose assays were based on those previously
demonstrated (Martinez et al., Angew Chem Int Ed 8:1318–1320, 1; Martinez et al., Anal Chem 10:3699–3707, 2; Martinez et al., Proc Nat Acad Sci USA 50:19606–19611, 3; Lu et al., Electrophoresis 9:1497–1500, 4; Abe et al., Anal Chem 18:6928–6934, 5). Reagents were spotted on the detection pad of the paper device and allowed to dry prior to spotting of samples. The ketone
test was a two-step reaction requiring a derivitization step between the sample spotting pad and the detection pad, thus for
the first time, confirming the ability of these paper devices to perform online multi-step chemical reactions. Following the
spotting of the reagents and sample solution onto the paper device and subsequent drying, color images of the paper chips
were recorded using a flatbed scanner, and images were converted to CMYK format in Adobe Photoshop CS4 where the intensity
of the color change was quantified using the same software. The limit of detection (LOD) for acetoacetate in artificial urine
was 0.5 mM, while the LOD for salivary nitrite was 5 μM, placing both of these analytes within the clinically relevant range
for these assays. Calibration curves for urinary ketone (5 to 16 mM) and salivary nitrite (5 to 2,000 μM) were generated.
The time of device fabrication to the time of test results was about 25 min. 相似文献
3.
Giuliana Bianco Giuseppe Novario Rosalia Zianni Tommaso R. I. Cataldi 《Analytical and bioanalytical chemistry》2009,393(8):2019-2027
Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography with high-resolution mass spectrometry (GC–HRMS)
was used to determine 2,4,6-trichloroanisole, 2,3,6-trichloroanisole, 2,3,4-trichloroanisole, 2,3,5,6-tetrachloroanisole,
pentachloroanisole, 2,4,6-tribromoanisole, 2-methylisoborneol, and 4-ethylguaiacol in wine samples. Two types of fiber coating
commonly employed for sampling trichloroanisoles in wine and cork stoppers, viz. a polar mixed 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) and a nonpolar 100 μm polydimethylsiloxane
(PDMS), both 1 cm in length, were compared. This study demonstrates that the most employed polar mixed fiber should not be
used with ethanol–water solutions, viz. wine samples, as its coating is not chemically and mechanically robust for sample extractions, as confirmed by environmental
scanning electron microscopy. Much more effective and reliable results were obtained with the PDMS fiber, which remained functional
for more than 80 analyses of red and white wine samples with satisfactory extraction efficiencies. Detection limits of investigated
compounds, under optimized experimental conditions, ranged from 0.2 to 0.4 ng/L at a signal-to-noise ratio of 3 and quantification
limits from 0.8 to 1.5 ng/L. The proposed method was successfully applied to commercially available Italian white and red
wines using 2,4,6-TCA-d5 as the internal standard.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Presented, in part, at the XXI Congresso Nazionale di Chimica Analitica, 21–25 September 2008, Arcavacata di Rende, CS (Italy). 相似文献
4.
Salwa Meredith Hashim Abdul Rahman Mohamed Subhash Bhatia 《Journal of Sol-Gel Science and Technology》2011,59(3):505-512
Perovskite-type La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF6428) thin-film membrane prepared by modified Pechini sol–gel process, was successfully deposited on porous support
of similar composition using dip-coating method. Fine grain and crack-free film with perovskite structure was obtained at
sintering temperature of 800 °C and dwelling time of 60 min. The cross-sectional image indicated that LSCF6428 thin-film membrane
coated on the porous support showed excellent adhesion to the support with uniform thickness. The minimum dense layer thickness
obtained by dip-coating method was around 0.5 μm. It was found that the oxygen permeability of the supported thin film was
lower than that of the perovskite support, which indicated that the pores of the support were reduced by thin-film deposition
on the support surface. The reduction in the pore size led to the more selective permeation mechanism contributes to the overall
permeation. Successful deposition of LSCF6428 thin-film membrane on porous support can be considered as a promising technique
for the preparation of oxygen separation membrane. 相似文献
5.
Zi Le Hua Jian Hua Gao Wen Bo Bu Ling Xia Zhang Hang Rong Chen Jian Lin Shi 《Journal of Sol-Gel Science and Technology》2009,50(1):22-27
Under typical dilute reactant compositions (3 ~ 5 wt% of surfactant template concentration) and conventional hydrothermal
conditions for mesoporous materials synthesis, successful preparation of hierarchically macro/mesoporous silica monoliths
was reported in this paper. The resultant materials were characterized by a series of techniques including powder X-ray diffraction,
N2 adsorption–desorption, SEM, TEM/EDS, and Hg porosimetry. A new kind of stable and hierarchically porous pure silica monoliths
was confirmed, which are featured with highly ordered mesoporous structures, rod-shaped unit particles, large specific surface
area of 492 m2/g, continuous macropores of about 4.0 μm in size and high macropore volume of about 13.1 cm3/g. Moreover, using the resultant silica monoliths as hard templates, carbon monoliths have been successfully replicated,
which inherit the structural characters of parent silica materials.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Determination of tetracycline residues in soil by pressurized liquid extraction and liquid chromatography tandem mass spectrometry 总被引:2,自引:0,他引:2
Vicente Andreu Pablo Vazquez-Roig Cristina Blasco Yolanda Picó 《Analytical and bioanalytical chemistry》2009,394(5):1329-1339
An optimized extraction and cleanup method for the analysis of chlortetracycline (CTC), doxycycline (DC), oxytetracycline
(OTC) and tetracycline (TC) in soil is presented. Soil extraction in a pressurized liquid extraction system, followed by extract
clean up using solid-phase extraction (SPE) and tetracycline determination by liquid chromatography tandem mass spectrometry
(LC-MS/MS) provided appropriate efficiency and reproducibility. Different dispersing agents and solvents for soil extraction
and several SPE cartridges for cleanup were compared. The best extraction results were obtained using ethylenediamine tetraacetic
acid-treated sand as dispersing agent, and water at 70 °C. The most effective cleanup was obtained using Strata-XTM sorbent in combination with a strong anion exchange cartridge. Recoveries ranged from 71% to 96% and precision, as indicated
by the relative standard deviations, was within the range of 8–15%. The limits of quantification (LOQs) by using LC-MS/MS,
based on signal-to-noise ratio (S/N) of 10, ranged from 1 μg kg−1 for TC to 5 μg kg−1 for CTC. These results pointed out that this technique is appropriate to determine tetracyclines in soils. Analysis of 100
samples taken in the Valencian Community revealed that, in soil, up to 5 μg kg−1 CTC, 15 μg kg−1 OTC, 18 μg kg−1 TC, and 12 μg kg−1 DC could be detected. Detection of the analytes in several samples, which typify great part of the Spanish agricultural soils,
should be outlined as most important result of this study.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
7.
Wettability of polypropylene capillary membranes during the membrane distillation process 总被引:1,自引:0,他引:1
Marek Gryta 《Chemical Papers》2012,66(2):92-98
Studies of membrane wettability in the membrane distillation process were performed with the application of hydrophobic capillary
membranes made of polypropylene. Three kinds of Accurel PP membranes (Membrana GmbH, Germany) differing in the diameter of
capillaries and pores as well as in the wall thickness were used. It was confirmed that membranes with lower wall thickness
and larger pore size provide higher yields of the process. The studies demonstrated that the pores of used membranes located
close to the external surface of capillaries are several times larger than those located inside the membrane wall. Based on
air permeability measurements it was found that external surface of the membranes with such large pores was completely wetted
by water after 50–80 h of membrane distillation. However, the pores located inside the wall with the diameter below 1 μm were
not wetted and electrical conductivity of the obtained distillate was maintained at the level of 3–6 μS cm−1. 相似文献
8.
Jian Li Jinting Cheng Yong Zhang Ponnampalam Gopalakrishnakone 《Colloid and polymer science》2009,287(1):29-36
We report on the formation of ordered arrays of micron-sized holes on the surface of polymer films cast from volatile solvents
in the presence of humidity in vacuum. A lower pressure in a vacuum chamber can accelerate the evaporation of solvent in the
same way as the accelerating action of the air flowing across the solvent surface and results in the formation of porous films
via the “breath figure” templating method. This vacuum technique has a good reproductiveness for the fabrication of the well-ordered
porous films in a large area. It is very controllable to prepare the porous films in a vacuum chamber via controlling the
vacuum level. The pore sizes can be easily tuned from 5.6 to 17.1 μm by changing the vacuum level. The mechanism for the formation
of the porous films in vacuum was also discussed. The polymer films with ordered porous structure and tunable pore sizes have
potential applications in many areas such as microarrays and as scaffolds for tissue engineering.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
《Journal of membrane science》2001,189(2):255-270
Several factors affecting microfiltration membrane fouling and cleaning, including backpulsing, crossflushing, backwashing, particle size, membrane surface chemistry, and ionic strength, were investigated with suspensions of latex beads. Approximately two-fold permeate volume enhancements over 1 h of filtration were obtained by using water or gas backpulsing, and 50% enhancement was obtained with crossflushing, for filtration of 1.0 μm diameter carboxylate modified latex (CML) particles using unmodified polypropylene (PP) membranes of 0.3 μm nominal pore diameter. When 0.2 μm diameter CML particles or mixtures of 1.0 and 0.2 μm CML particles were used, however, the average flux decreased 60% compared with using 1.0 μm CML particles for experiments with or without backpulsing.PP membranes were rendered hydrophilic with neutral or positively on negatively charged surfaces by grafting monomers of poly(ethylene glycol 200) monomethacrylate (PEG200MA), dimethyl aminoethyl methacrylate (DMAEMA), or acrylic acid (AA), respectively, to the base PP membranes. Filtration experiments show that fouling is not strongly dependent on membrane surface chemistry for filtration of 1.0 μm CML particles without backpulsing. With backpulsing, however, a 10% increase and a 20% decrease of permeate volumes collected in 1 h were observed when the CML particles and the membranes had like charges and opposite charges, respectively, compared to the permeate collected with the unmodified membrane. Using the PP membranes modified with AA, permeate volumes with backpulsing decreased 30 and 40% when NaCl concentrations of 0.01 and 0.1 M, respectively, were added to the feed. However, the permeate volumes did not vary significantly with changing ionic strength for filtration without backpulsing. 相似文献
10.
Ceramic hollow fibre membranes which have an asymmetric structure have been prepared in one step, using an immersion induced phase inversion technique. With this method, membranes with a high surface area per unit volume ratio can be produced, while production cost is dramatically reduced. Yttria-stabilised zirconia (YSZ) is selected as a membrane material, as it is relatively inexpensive and has superior mechanical strength as well as oxygen ion conducting properties. Therefore, both the porous and non-porous membranes prepared from the YSZ have potential applications. For example, the porous YSZ membranes can be used for fluid separations in harsh environments where normal polymeric membranes cannot be sustained, while the non-porous YSZ membranes can be applied as a solid electrolyte in electrochemical devices such as solid oxide fuel cells, oxygen pumps and chemical gas sensors.Gas permeation analysis suggests that non-porous YSZ hollow fibre membranes can be prepared at sintering temperature of 1400 °C or greater, below which the membrane contains pores. Pore sizes of the YSZ porous membrane prepared fall into the pore size range of ultrafiltration membranes. However, the surface porosities of the membranes prepared from two-population sized particles at sintering temperatures of 1200 °C and 1400 °C are around 5000 m−1 and 300 m−1, respectively. The former is comparable to polymeric membranes, while the latter is an order of the magnitude smaller. 相似文献
11.
Masato Kukizaki 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,340(1-3):20-32
We have recently proposed a new method for generating uniformly sized microbubbles from Shirasu porous glass (SPG) membranes with a narrow pore size distribution. In this study, to obtain a high gas permeation rate through SPG membranes in microbubble formation process, asymmetric SPG membranes were used. At the transmembrane/bubble point pressure ratio of less than 1.50, uniformly sized microbubbles with a bubble/pore diameter ratio of approximately 9 were generated from an asymmetric SPG membrane with a mean pore diameter of 1.58 μm and a skin-layer thickness of 12 ± 2 μm at a gaseous-phase flux of 2.1–24.6 m3 m−2 h−1, which was much higher than that through a symmetric SPG membrane with the same pore diameter. This is mainly due to the much smaller membrane resistance of the asymmetric SPG membrane. Only 0.27–0.43% of the pores of the asymmetric SPG membrane was active under the same conditions. The proportion of active pores increased with a decrease in the thickness of skin layer. In contrast to the microbubble formation from asymmetric SPG membranes, polydispersed larger bubbles were generated from asymmetric porous ceramic membranes used in this study, due to the surface defects on the skin layer. The surface defects were observed by the scanning electron microscopy and detected by the bubble point method. 相似文献
12.
M. Sorrenti L. Catenacci M. C. Bonferoni G. Sandri C. Caramella G. P. Bettinetti 《Journal of Thermal Analysis and Calorimetry》2010,102(1):337-342
Interactions between diltiazem hydrochloride (DTZ), an orally active calcium antagonist used in the treatment of angina and
hypertension, and lambda carrageenan (λCRG), which has been successfully used in matrix formulations to obtain constant and pH-independent release of basic drugs,
were investigated in solid state using differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). The effect
of particle size on thermal behaviour of the drug and the polymer was assessed, and the result used to select the most suitable
granulometric fractions for the study. Physical mixtures ranging in composition from 3:1 to 0.6:1 (by weight) drug-to-polymer
ratios were analyzed as such and after kneading. A stoichiometric ratio of interaction of 1.6:1 (w/w) DTZ:λCRG was found, in agreement with that obtained from dialysis equilibrium studies. All the examined granulometric fractions
(<45 μm, 45–75 μm, 75–105 μm and >105 μm) of the interaction product showed similar thermal behaviour. 相似文献
13.
Mohammed A. Abounassif Mohammed M. Hefnawy Gamal A. E. Mostafa 《Monatshefte für Chemie / Chemical Monthly》2012,73(Z1):365-371
Abstract
A stereoselective HPLC method has been developed for the simultaneous determination of oxprenolol enantiomers in urine and pharmaceutical products. Enantiomeric resolution of oxprenolol was achieved on cellulose tris(3,5-dichlorophenylcarbamate) immobilized onto a 5 μm spherical porous silica chiral stationary phase (CSP) known as Chiralpak IC with UV detection at 273 nm. The mobile phase consisted of n-hexane:isopropanol:triethylamine 70:30:0.1 (v/v/v) at a flow rate of 1.0 cm3/min. The method was validated for its linearity, accuracy, precision, and robustness. The calibration curves were linear over the range of 0.5–75 μg/cm3, with a detection limit of 0.1 μg/cm3 for each enantiomer. An average recovery of 99.0% and a mean relative standard deviation of 2.6% at 40.0 μg/cm3 for S-(−)- and R-(+)-enantiomers were obtained. The overall recoveries of oxprenolol enantiomers from pharmaceutical formulations were in the range 97.5–99.0%, with RSDs ranging from 0.6 to 0.8%. The mean extraction efficiency of oxprenolol from urine was in the range of 86.0–93.0% at 0.5–5 μg/cm3 for each enantiomer. The assay method proved to be suitable as a chiral quality control for oxprenolol formulations using HPLC and for therapeutic drug monitoring. 相似文献14.
Sari MM 《Applied biochemistry and biotechnology》2011,163(8):1020-1037
Cupric ion-chelated poly(hydroxyethyl methacrylate-n-vinyl imidazole) (poly(HEMA-VIM)) microspheres prepared by suspension polymerization were investigated as a specific adsorbent
for immobilization of yeast invertase in a batch system. They were characterized by scanning electron microscopy, surface
area, and pore size measurements. They have spherical shape and porous structure. The specific surface area of the p(HEMA-VIM)
spheres was found to be 81.2 m2/g with a size range of 70–120 μm in diameter, and the swelling ratio was 86.9%. Then, Cu(II) ion chelated on the microspheres
(546 μmol Cu(II)/g), and they were used in the invertase adsorption. Maximum invertase adsorption was 51.2 mg/g at pH 4.5.
Cu(II) chelation increases the tendency from Freundlich-type to Langmuir-type adsorption model. The optimum activity for both
free and adsorbed invertase was observed at pH 4.5. The optimum temperature for the poly(HEMA-VIM)/Cu(II)-invertase system
was found to be at 55 °C, 10 °C higher than that of the free enzyme at 45 °C. V
max values were determined as 342 and 304 U/mg enzyme, for free and adsorbed invertase, respectively. K
m values were found to be same for free and adsorbed invertase (20 mM). Thermal and pH stability and reusability of invertase
increased with immobilization. 相似文献
15.
Zhang Q Kusunoki T Xu Q Wang H Kobayashi T 《Analytical and bioanalytical chemistry》2007,388(3):665-673
Phase separation of poly(acrylonitrile–co-methacrylic acid) in compressed liquid CO2 resulted in formation of a porous imprinted membrane which preferentially adsorbed uracil (URA). The cross-section of the
membrane was observed by SEM, which revealed its porous structure. The mechanical strength of the membrane indicated formation
of a rigid matrix with high tensile strength (4.4 N mm−2). The imprinted membranes bound highly selectively to URA (12.8 μmol g−1) but binding to dimethyluracil (DMURA), thymine, and cytosine was less (0.7, 0.8, and 0.9 μmol g−1, respectively). When DMURA was similarly used to prepare an imprinted membrane in liquid CO2 there was less binding of DMURA to the imprinted membrane obtained. The URA-imprinted membranes were evaluated by IR spectroscopy
before and after URA extraction. The results indicated that hydrogen bonding was the mechanism of binding of URA to the imprinted
membrane. Competitive binding studies were performed with binary mixtures of URA and its analogues. The URA-imprinted membrane
enabled good separation of URA from cytosine, DMURA, and thymine, with separation factors of 3.0, 3.8, and 2.5, respectively.
It was confirmed that the compressed liquid CO2 contributed to efficient formation of template substrate sites in the URA-imprinted membrane. 相似文献
16.
We present an improved Monte Carlo integration method to calculate the accessible pore size distribution of a porous solid
having known configuration of solid atoms. The pore size distribution obtained with the present method is consistent with
the accessible volume and the accessible geometric surface area presented in previous publications (Do and Do, in J. Colloid
Interface Sci. 316(2):317–330, 2007; Do et al. in Adsorpt. J., 2010). The accessible volume, accessible geometrical surface area and the pore size distribution method construct an unambiguous
and robust single framework to characterize porous solids. This framework is based on the derivation of the space accessible
to the center of mass of a probe molecule. The accessible pore size presented is an absolute quantity in the sense that a
zero value is possible. We present the entire framework of this characterization method and compare the improved method with
the one presented previously for a set of porous solids such as graphitic slit pores, defective slit pores, bundle of carbon
nanotubes, zeolite and some metal organic frameworks. 相似文献
17.
A diffusion junction between two paired gold electrodes is created in a bipotentiostatic electro-deposition process. Gold
metal is deposited simultaneously on two adjacent disc electrodes (100 μm diameter, approximately 125 μm separation) until
short-circuit conditions trigger the end point of the electro-deposition. Symmetric gold junctions with typically 5 μm average
inter-electrode gap size, 140 μm gap length, and approximately 18 μm junction depth are obtained. These paired gold electrodes
are employed in generator–collector mode to give well-defined steady-state feedback currents even for extremely low concentrations
of analyte (sub-μM) and without any contributions from capacitive charging. Four redox systems are investigated spanning a
wide range of diffusion coefficients: (1) the one-electron oxidation of iodide to iodine, (2) the two-electron oxidation of
hydroquinone to benzoquinone, (3) the two-electron reduction of alizarin red S, and (4) the one-electron oxidation of the
redox protein cytochrome c. Consistent results for these redox systems suggest that (1) the junction zone between the two electrodes is dominating the
behaviour of the electrode in particular for the slower diffusing systems and (2) the paired gold electrode junction can be
calibrated and employed for electroanalysis at very low concentrations and for a wider range of analytically relevant redox
systems.
Dedicated to Professor Keith B. Oldham, on the occasion of his 80th birthday 相似文献
18.
Yew JY Soltwisch J Pirkl A Dreisewerd K 《Journal of the American Society for Mass Spectrometry》2011,22(7):1273-1284
We recently demonstrated that ultraviolet laser desorption ionization orthogonal time-of-flight mass spectrometry (UV-LDI
o-TOF MS) could be used for the matrix-free analysis of cuticular lipids (unsaturated aliphatic and oxygen-containing hydrocarbons
and triacylglycerides) directly from individual Drosophila melanogaster fruit flies (Yew, J. Y.; Dreisewerd, K.; Luftmann, H.; Pohlentz, G.; Kravitz, E. A., Curr. Biol.
2009, 19, 1245–1254). In this report, we show that the cuticular hydrocarbon, fatty acid, and triglyceride profiles of other insects
and spiders can also be directly analyzed from intact body parts. Mandibular pheromones from the jaw of a queen honey bee
are provided as one example. In addition, we describe analytical features and examine mechanisms underlying the methodology.
Molecular ions of lipids can be generated by direct UV-LDI when non-endogenous compounds are applied to insect wings or other
body parts. Current sensitivity limits are in the 10 pmol range. We show also the dependence of ion signal intensity on collisional
cooling gas pressure in the ion source, laser wavelength (varied between 280–380 nm and set to 2.94 μm for infrared LDI),
and laser pulse energy. 相似文献
19.
G. Vijayakumar S. N. Karthick A. R. Sathiya Priya S. Ramalingam A. Subramania 《Journal of Solid State Electrochemistry》2008,12(9):1135-1141
New poly (vinylidenefluoride-co-hexafluoro propylene) (PVDF-HFP)/CeO2-based microcomposite porous polymer membranes (MCPPM) and nanocomposite porous polymer membranes (NCPPM) were prepared by
phase inversion technique using N-methyl 2-pyrrolidone (NMP) as a solvent and deionized water as a nonsolvent. Phase inversion occurred on the MCPPM/NCPPM
when it is treated by deionized water (nonsolvent). Microcomposite porous polymer electrolytes (MCPPE) and nanocomposite porous
polymer electrolytes (NCPPE) were obtained from their composite porous polymer membranes when immersed in 1.0 M LiClO4 in a mixture of ethylene carbonate/dimethyl carbonate (EC/DMC) (v/v = 1:1) electrolyte solution. The structure and porous morphology of both composite porous polymer membranes was examined
by scanning electron microscope (SEM) analysis. Thermal behavior of both MCPPM/NCPPM was investigated from DSC analysis. Optimized
filler (8 wt% CeO2) added to the NCPPM increases the porosity (72%) than MCPPM (59%). The results showed that the NCPPE has high electrolyte
solution uptake (150%) and maximum ionic conductivity value of 2.47 × 10−3 S cm−1 at room temperature. The NCPPE (8 wt% CeO2) between the lithium metal electrodes were found to have low interfacial resistance (760 Ω cm2) and wide electrochemical stability up to 4.7 V (vs Li/Li+) investigated by impedance spectra and linear sweep voltammetry (LSV), respectively. A prototype battery, which consists
of NCPPE between the graphite anode and LiCoO2 cathode, proves good cycling performance at a discharge rate of C/2 for Li-ion polymer batteries. 相似文献
20.
Concheiro M de Castro A Quintela O Cruz A López-Rivadulla M 《Analytical and bioanalytical chemistry》2008,391(6):2329-2338
An LC-MS/MS method using 0.5 ml of oral fluid was developed for the determination of morphine, codeine, 6-monoacetylmorphine,
methadone, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, benzoylecgonine, cocaine, delta-9-tetrahydrocannabinol, zolpidem, zopiclone, alprazolam, clonazepam, oxazepam,
nordiazepam, lorazepam, flunitrazepam, diazepam, diphenhydramine and amitriptyline. The method was fully validated in terms
of linearity (the method was linear between 1–5 μg/L and 100–200 μg/L) recoveries (7.5–82.6%), within-day and between-day
precisions and accuracies (CV and MRE, both <15%), limits of detection (0.5 μ g/L) and quantitation (the lowest point on the
calibration curve), relative ion intensities, freeze-and-thaw stability and matrix effect. The method was applied to preserved
oral fluid collected by a special commercial device, the StatSure Saliva Sampler™. 相似文献