最新刊期
卷 33 ， 期 4 ， 2014
- 摘要：In this article，an unique electrochemiluminescence sensor was built to study DNA damage due to perfluorooctanoic acid（PFOA）.First of all,combining the special properties of quantum dots（QDs） and nano gold particles（NG）,the quantum dots-nano gold（QDs-NG） composite particles was prepared.Then,the calf thymus DNA（ct-DNA） was modified onto the surface of glassy carbon electrode（GCE）.After dried in the incubator,the QDs-NG composite particles was dropped onto the electrode.In this way,the electrochemiluminescence sensor based on QDs-NG particles was established.It was used to study the enhancement effect of QDs luminous intensity based on NG particles.And further,the DNA damage due to PFOA was also investigated using the electrochemiluminescence sensor.The atomic force microscope（AFM） and X ray photoelectron spectroscopy（XPS） were also adopted to characterize the surface morphology of modified electrode.The results showed that the existence of the NG particles had obvious enhancement effect on the luminous intensity of QDs，and the electrochemiluminescence intensity was increased about four times.On the other hand,after the interaction between PFOA and ct-DNA at 37 ℃,electrochemiluminescence intensity was decreased to a great degree,which indicated that PFOA caused DNA damage.关键词：quantum dots;electrochemiluminescence;DNA damage;perfluorooctanoic acid
- 2079
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发布时间： - 摘要：A analytical method was established for the simultaneous screening and determination of 26 veterinary drugs,including 14 sulfonamides,4 β-agonists，2 fluoroquinolones，3 tetracyclines and 3 organic phosphorus pesticides,in pork by liquid chromatography-quadrupole-time of flight mass spectrometry(HPLC-Q-TOF-MS).The QuEChERS(Quick,Easy,Cheap,Effective,Rugged,and Safe) method was used for sample preparation．The samples were extracted with acidified acetonitrile-methanol(1% acetic acid，10% methanol),and cleaneded up by dispersive solid-phase extraction using C18 dispersant sorbent，then degreased with hexane.The 26 veterinary drugs were separated on an Eclipse Plus C18(3.0 mm×100 mm,1.8 μm) column using water with 0.1% formic acid(A) and methanol(B) as mobile phase by gradient elution in 19 min，and analyzed by MS under ESI positive ionization mode．The quantitation analysis was carried out by extracting peak area with accurate mass．The confirmatory analysis of target compounds was performed with the qualitative fragments．The results showed that the limits of quantitation(LOQ，S/N=10) of 26 target compounds in pork ranged from 0.4 μg/kg to 10 μg/kg．The mean recoveries of 26 veterinary drugs were in the range of 56.7%-106.2%,with RSDs of 7.7%-15.8%.With the advantages of simplicity，fast，efficient,the method was suitable for the analysis of 26 veterinary drugs in pork.关键词：high performance liquid chromatography-tandem mass spectrometry(HPLC-Q-TOF-MS );pork;veterinary drug;QuEChERS;multiple residues;rapid screening
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发布时间： - 摘要：Two types of water-soluble multicolor carbon dots(CDs) were prepared through the reactions of egg white or milk with glucose by hydrothermal method.The CDs derived from egg white/glucose(E-CDs) and milk/glucose(M-CDs) were purified by filtering membrane and column chromatography.Particle sizes,UV-vis absorption and emission spectra and surface groups of the two types of CDs were characterized using transmission electron microscopy(TEM),ultraviolet spectrometry(UV),fluorescence spectroscopy(FL),Fourier transform infrared spectroscopy(FTIR) techniques,and their multicolor cell imaging were evaluated by incubation with mouse melanoma cells.The results showed that the two types of multicolor CDs prepared by hydrothermal method were highly water-soluble with particles sizes of 2.5 nm and 4.9 nm,respectively,which could emit bright multicolor fluorescence under the excitation of UV-vis light.Their maximum absorption wavelength was 250 nm,whereas the maximum fluorescence emission wavelengths were located at 410 nm and 400 nm for E-CDs and M-CDs,respectively.Meanwhile,the obtained CDs exhibited upconversion fluorescence properties in the excitation wavelength range of 660- 800 nm.The emission peak positions from both CDs shifted to longer wavelengths,and the intensity gradually decreased with the increase of excitation wavelengths.FTIR spectra analysis revealed the presence of —COOH,—NH2 and —OH on both of CDs’ surface.Cell imaging results demonstrated that fluorescence in the cells cultured with CDs was clearly visible under 405 nm and 488 nm laser irradiation,respectively,and both of the CDs showed very low cytotoxicity when the CDs’ concentration was less than 2.5 mg/mL.关键词：water soluble fluorescent carbon dots;fluorescent probe;cell imaging
- 1984
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- 1395
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发布时间： - 摘要：The thermal decomposition behaviors,including weight loss,heat flow and gaseous decomposition products of cashew nut shell liquid(CNSL) modified thermoplastic phenolic resin were investigated by TG-DSC-MS coupling techniques at different kinds of atmosphere.The kinetic parameters of CNSL modified thermoplastic phenolic resin were obtained from equation Coats-Redfern.The results showed that the atmosphere had an obvious effect on the pyrolysis of sample.Compared with that at N2 atmosphere,two major weight loss steps at air atmosphere existed,the total weight loss steps and temperature zones both also increased,and the thermal decomposition was more complete.At N2 atmosphere,the major weight loss zone showed endothermic in the DSC curves at different heating rates.At air atmosphere,the thermic response depended on the heating rates in the first major weight loss stage,but appearing exothermic in the second weight loss stage.The pyrolysis kinetics could be simplified as a model of a first-order reaction with four sections model at N2 atmosphere and another model of a first-order reaction with six sections at air atmosphere while α value varied from 0.10 to 0.90.In N2 atmosphere,the activation energies at different stages were 17，65，32,13 kJ?mol-1,respectively,and in air atmosphere,the activation energies at different stages were 72，23，14，12，19,57 kJ?mol-1,respectively.The signal intensity of ion current varied with temperature,and the atmosphere had an obvious effect on the gaseous decomposition products.In inert atmosphere(Ar),CNSL modified thermoplastic phenolic resin more easily cracked into aromatic hydrocarbons,e. g. benzene, toluene, dimethylbenzene, trimethylbenzene, ethyltoluene，ethylbenzene，phenol，methyl phenol，dimethylphenol，trimethylphenol, and alkanes，e.g.ethanol，methane，propane，butane，hexane，pentane.The aromatic hydrocarbons were the main gas products,which productions were up to a peak at 305-333 ℃and another peak at 408-460 ℃,respectively.In air atmosphere,the gaseous products were mainly H2O，CO2 and formic acid.Furthermore,the relative contents of H2O，CO2 and formic acid increased obviously.Only a few of aromatic hydrocarbons,eg.benzene and phenol were detected in the first major weight loss stage without any alkanes.关键词：cashew nut shell liquid;thermoplastic phenolic resin;thermal decomposition;TG-DSC-MS technique;kinetics
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发布时间： - 摘要：In this paper,the evolution of several analytical indicators and the low field nuclear magnetic resonance(LF-NMR) T2 relaxation characteristics of sunflower oil stored at 25，65 ℃,respectively,were investigated.And the correlation model between LF-NMR results and the analytical indicators was established and experimentally verified.The results indicated that ,when stored at 65 ℃,the analytical indicators,including peroxide value(PV),conjugated dienes(K232),conjugated tienes(K270),p-anisidine value(p-AV),TPC content and the LF-NMR T2 peak area(S21，S22) all increased exponentially(r2＞0.93),while the S23 and the single component relaxation time(T2W) decreased exponentially as the storage time was prolonged(r2＞0.98).The multiple regression analysis results showed that the correlation model between LF-NMR results and the analytical indicators could be well established and successfully verified(r2＞0.94).When stored at 25 ℃,although the analytical indicators and the LF-NMR results changed less than those of 65 ℃,the PV，K232，TPC content increased linearly as the time was prolonged(r2＞0.95),while no obvious relationship could be found between the K270，p-AV，IV or T2 relaxation characteristics and the storage time.Meanwhile,the correlation of the model between LF-NMR results and the analytical indicators was also poor.关键词：sunflower oil;storage;analytical indicators;LF-NMR;relaxation characteristic
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发布时间： - 摘要：A glassy carbon electrode modified with GR/Au nanocomposites was prepared for the simultaneous determination of isoniazid(INZ) and ascorbic acid(AA).In 0.1 mol?L-1 PBS(pH 3.5) buffer solution,the electrochemical behaviors of INZ and AA were investigated by cyclic voltametrmy(CV).The results indicated that the anodic peak currents of both INZ and AA showed linear relationships with the square root of scan rate over a wide range of 50-300 mV?s-1.Furthermore,the nanocomposites modified electrode showed an efficient catalytic role in the electro-oxidation of INZ and AA,leading to a remarkable peak resolution(ΔV=170 mV) between the two compounds.Under the optimal experimental conditions,the anodic peak currents were linear over ranges of 3.0×10-6-1.5×10-4 mol?L-1 for INZ and 3.0×10-5-1.0×10-3 mol?L-1 for AA,with detection limits of 8.0×10-7 mol?L-1 and 6.0×10-6 mol?L-1,respectively.The proposed method was successfully applied in the determination of INZ and AA in commercial drugs.关键词：GR/Au nanocomposites;isoniazid;ascorbic acid;cyclic voltammetry
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发布时间： - 摘要：The pyrolysates of 10 perfumes,including perillartine,β-ionone,sclareolide,iso eugenol,benzal dehyde,2-acetyl pyrazine,2-acetyl thiazole,3-acetyl pyridine,hawthorn tincture and shu-lan absolute,were identified by on-line gas chromatography-mass spectrometry (GC-MS) under helium atmospheres at 300 ℃,600 ℃ and 800 ℃,respectively.The relative percentage contents of aromatic components were established,and effects of pyrolysing temperatures on amounts of aromatic components formed during the pyrolysing procedure were analyzed.Meantime,the relationship between structures of perfume compositions and amounts of aromatic compounds was speculated and accounted based on the theroy of the structures and property of organic compounds.The results showed that:β-ionone,sclareolide,iso-eugenol,shu lan absolute could be pyrolysed into aromatic compounds (including benzene,indene,naphthalene and their derivates) at 800 ℃,among which the percentage content of the aromatic components in pyrolysates of β-ionone came to 16.290% and that in pyrolysates of shu lan absolute was 5.376%.But aromatic components were not detected in the pyrolysates of 2-acetylpyrazine,2-acetylthiazole,3-acetylpyridine.Therefore,the structures of perfume compositions were an important effect on the amounts of aromatic compounds pyrolysed by perfumes.With the increase of pyrolysis temperature,the aromatic compound percentage in pyrolysates was increased obviously.For example,the aromatic components of β-ionone pyrolysates at 300 ℃ were almost not determined,and the total of aromatic components at 600 ℃ was lower than 1%,but the total of aromatic components at 800 ℃ came to 1628%.As additives used for cigarette,2-acetylpyrazine,2-acetylthiazole and 3-acetylpyridine are suitable.关键词：pyrolysis/gas chromatography-mass spectrometry;structures of perfumes;aromatic compounds
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- 1128
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发布时间： - 摘要：A supercritical fluid chromatographic(SFC) method was developed for the determination of tocopherols and α-tocopheryl acetate in cosmetics.Different types of samples were sequentialy dispersed and extracted with acetonitrile water solution-hexane based on matix types.The chromatographic separation was conducted with a XBridge(Viridis@BEH,250 mm×4.6 mm,5 μm) by gradient elution using CO2 as mobile phase and 2-propanol∶hexane(1∶1) as modifier.The detection was performed with a photodiode-array(PDA) detector.The extraction procedures and chromatographic conditions were optimized.The results showed that the limits of quantitation(LOQ,S/N=10) were 50 mg/kg for four tocopherols and 25 mg/kg for α-tocopheryl acetate.The average recoveries ranged from 81.3% to 109.5% with relative standard deviations(RSDs) not more than 12.8%.The method is simple,rapid and accurate,and is suitable for the determination of four tocopherols and α-tocopheryl acetate in cosmetics.关键词：supercritical fluid chromatography(SFC);cosmetics;tocopherol;α-tocopheryl acetate
- 2055
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- 1186
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发布时间： - 摘要：An HPLC method was developed for the determination of trichloroacetic acid in urine based on the interface reaction between trichloroacetic acid and pyridine.An orthogonal experiment was carried out and the result showed that there was no significant correlation among the factors.The derivatization conditions such as the volume of urine and reagent,alkali concentration,reaction time and temperature,and the chromatographic conditions were optimized.Under the optimal conditions,the working curves of the analyte was established,the linear range of trichloroacetic acid was between 0.002 0 mg/L and 20.0 mg/L,with correlation coefficient（r） of 0.999 7 and detection limit（S/N=3） of 0.1 μg/L.The average recoveries of trichloroacetic acid in urine samples were in the range of 91.9%-105% with relative standard deviations of 3.5%-4.6%.The results showed that the urine sample was simultaneously enriched and purified by using the interface reaction,and the detection limit was greatly reduced.The established method was turned out to be simple,rapid,sensitive,accurate and environment friendly.关键词：derivatization;interface reaction;high performance liquid chromatography;urinary metabolites;trichloroacetic acid
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- 1002
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发布时间： - 摘要：A gas chromatography-mass spectrometric（GC-MS） method was developed for the determination of 1,2-dichloroethane in textiles.The samples were extracted with methanol under ultrasonic assistance.The separation and quantification of 1,2-dichloroethane were achieved on an TG-624 column（30 m×0.32 mm×1.8 μm） using temperature programming.The identification and quantification of 1,2-dichloroethane were performed by GC-MS under full scan and selected ion monitoring scan with the external standard method.The result indicated that the calibration curve showed a good linear relationship between peak area and concentration of 1,2-dichloroethane in the range of 0.05-30 mg/L,with a correlation coefficient of 0.999 3.The limit of detection was 0.50 mg/kg.The average recoveries of 1,2-dichloroethane from 7 typical textile matrices including viscose fiber,polyester,wool,nylon,ramie,polyacrylonitrile fiber and cotton,at three spiked concentration levels of 0.5,1.0,5.0 mg/kg were in the range of 85.2%-101.4% with relative standard deviations（RSDs） of 4.0%-7.4%.With the advantages of low detection limit,good accuracy and high precision,the method could be used for residue surveillance of 1,2-dichloroethane in textile samples.关键词：textiles;1,2-dichloroethane;gas chromatography-mass spectrometry（GC-MS）
- 2077
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- 1041
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发布时间： - 摘要：In this paper,the hydrolysis of carbaryl was combined with the diazotization coupling reaction to produce the azoic compounds,which have strong surface-enhanced Raman scattering（SERS） effect.Based on the principle,a novel method for the determination of carbaryl was established using shell isolated Au@SiO2 nanoparticles as SERS substrates which consist of Au nanoparticle cores with a diameter of about 55 nm and the silica shell with its thickness about 1-2 nm.The conditions of the reaction and the method of the detection were optimized.Under the optimal conditions,the linearity was observed in the range of 5.0-100.0 mg/L with a limit of detection of 1.7 mg/L at 1 218 cm-1.The method was applied in the analysis of carbaryl in coconut juice with recoveries of 100.4%-105.1% and relative standard deviations （RSDs） of 2.8%-4.9%.The results indicated that this proposed method was simple,rapid,low-cost and low-consuming.The proposed method was applicable for in situ detection of carbaryl in real samples.关键词：diazotization-coupling reaction;surface-enhanced Raman spectroscopy;rapid analysis;coconut juice;carbaryl
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发布时间： - 摘要：A method was established for the determination of 20 phthalic acid esters（PAEs） in waterborne wall coatings by gas chromatography-mass spectrometry（GC-MS） after dispersive solid phase extraction（d-SPE） cleanup.The samples were dispersed with water,and stirred uniformly,then extracted with acetonitrile-methyl tert-butyl ether（9∶1）.The ultimate solution was detected by GC-MS under selected ion monitoring mode and quantified by the external standard method.The calibration curves of 20 PAEs were linear in the range of 0.01-10 mg/L with correlation coefficients（r） more than 0.99.The limits of detection（LODs） of the method for target compounds ranged from 0.07 mg/kg to 1.40 mg/kg,and the limits of quantitation of the method（LOQs） varied from 0.3 mg/kg to 4.7 mg/kg.The mean recoveries ranged from 86.3% to 115.3% with relative standard deviations（RSDs） less than 8%.This method was suitable for the identification and quantification of 20 PAEs in waterborne wall coatings due to its simplicity and accuracy.关键词：phthalic acid esters;waterborne wall coatings;dispersive solid phase extraction;gas chromatography-mass spectrometry
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发布时间： - 摘要：The fragmentation pathways and mechanisms of dialkyl（≥C2） dimethylpyrophosphonate were studied under electron impact（EI） condition using gas chromatography mass spectrometry（GC-MS） and gas chromatography tandem mass spectrometry（GC-MS/MS）.The parents of ions were found by MS/MS in parents scan mode,and the products of ions were found in product scan mode.The relationship of ions in EI mass spectra were built,while the fragmentation pathways were gotten.The main fragment ions were interpreted using the basic mechanism of ion fragmentation of radical site and charge site initiation theory.The experimental result showed that the EI mass spectra of most of dialkyl（≥C2） dimethylpyrophosphonate released no molecular ions.The fragment ions of m/z 175,158,157,143,97,79,65 and 47 were found in all EI MS of dialkyl（≥C2） dimethylpyrophosphonate.For the dialkyl dimethylpyrophosphonate,the reaction of molecular ions initiated at the radical site and charge site of unsaturated oxygen,saturated oxygen and π bond.The molecular ions produced different fragment ions from the α-cleavage reaction and inductive-cleavage reaction with hydrogen rearrangement.These fragment ions continued to fragment and produce ions from α-cleavage,i cleavage and other reactions.The fragmentation rules of dialkyl dimethylpyrophosphonate could provide a reference for the analysis and identification of this kind of compounds and other similar chemicals.关键词：dialkyl dimethylpyrophosphonate;EI-MS;MS/MS;fragmentation characterization
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发布时间： - 摘要：A copper（Ⅰ） complex with N,N′-diphenyl thiourea［C32H38ClCuN6O2S2］ was synthesized by a facile method of in situ reduction of copper（Ⅱ） to copper（Ⅰ）.The structure was characterized by elemental analysis,IR and X ray single-crystal diffraction.The crystal structure of the complex belongs to monoclinic system with space group P21/c.The cell parameters were as follows:a=0.957 4（5） nm，b=3.210 7（17） nm，c=1.222 8（7） nm;β=111.877（8）°，V=3.488（3） nm3，Z=4，Dc=1.336 mg/m3,F（000）=1 464,and the final structure deviation factor R1=0.047 5，ωR2=0.130 7.Based on multiplicate intermolecular hydrogen bonds,three-dimentional supramolecular structure in the complex was fabricated in solid phase.Additionally,the spectral property,thermal stability and electrochemical behavior of the complex were also studied in order to provide a valuable reference and a theoretical basis for further study of the structures and functional properties of this kind of metal-organic complexes.关键词：diphenylthiourea copper（Ⅰ） complex;crystal structure;spectral property;thermal stability;electrochemical behavior
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- 1000
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发布时间： - 摘要：A new contactless conductivity detector for microchip was developed.The electrode board and chip were independent of each other.The microfluidic chip was consisted of a 1.3 mm thickness of flat glass as cover and a substrate glass in which the same size of separation channel and reference channel were etched.The high frequency signal from signal generator was divided into two parts which were input into two pairs of the same electrodes in a printed circuit board subjected the separation channel and reference channel in the chip,respectively.When the analyte was passed the detection zone in separation channel,the conductivity difference between separation channel and reference channel were detected to be a peak of electropherogram.The experimental conditions,including excitation frequency and voltage,distance between two electrodes,and length of electrodes were investigated and optimized.Its feasibility and performance were demonstrated by analyzing inorganic ions.The optimized conditions were as follows:excitation frequency:100 kHz,excitation voltage:10 V(in peak to peak),distance between two electrodes:0.9 mm.Under the optimized conditions, the limit of detection reached to 12 μmol?L-1 for K+.This contactless conductivity detector was suitable for the analytical chip manufactured of ordinary thickness of flat glass as cover,and was also convenient in application for its independence between electrode board and chip.关键词：contactless conductivity detection;differential detection;microfluidic chip
- 2055
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- 980
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- 1
发布时间： - 摘要：In Britton-Robinson（BR） buffer solution at pH 2.1-4.1,acriflavine（AF） reacted with cefotaxime sodium（CFTM） to form an ion association complex that quenched the fluorescence of acriflavine and whose compound ratio was 1∶1.The measurement wavelength of fluorescence quenching was located at λex/λem=266 nm/506 nm.The linear range for CFTM ranged from 0.07 mg/L to 5.0 mg/L,and its detection limit was 0.021 mg/L.In this study,the fluorescence spectra characteristics,the optimum reaction conditions and effect of foreign substances were investigated.The composition of ion-association complexes was discussed.Based on the ion-association reaction,a high sensitive,simple and rapid method for the determination of CFTM was proposed.The method was applied for the determination of CFTM in human serum and urine samples with satisfactory results.关键词：cefotaxime sodium;acriflavine;fluorescence quenching
- 2048
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- 955
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- 1
发布时间： - 摘要：An electron beam pumped rare gas excimer lamp（EBEL） was utilized to emit the intensive vacuum ultraviolet（VUV） radiation at 126 nm for soft single photon ionization（SPI） of polycyclic aromatic hydrocarbons（PAHs） in a soil sample.The VUV light source was coupled to a compact and mobile time-of-flight mass spectrometer（TOF MS） for the on-line detection of PAHs.The PAH desorption gases from soil sample were introduced into the mass using direct sample introduction with a cappillary.The effects of moderate desorption temperatures and desorption time on 16 PAHs were discussed,and the influences of the ionization efficiency of the single photon ionization on limits of detection were also considered.The quantitative analysis was carried out by measuring the mixture of a standard gas,and the limits for detection for 16 PAHs in the environmental soil were found to be at a μg/mL level.关键词：single photon ionization;polycyclic aromatic hydrocarbons;vacuum ultraviolet radiation;direct sample introduction;limit of detection;ionization efficiency
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- 2
发布时间： - 摘要：The chiral separation of zopiclone was studied by using reversed-phase high performance liquid chromatography with β-cyclodextrin（β-CD） as chiral mobile additive.Effects of some factors such as concentration of β-CD,content of methanol,pH value,flow rate and temperature on resolution were investigated.The experimental conditions were investigated by the single variable method.The best chromatographic conditions were as follows:column:Inertsil ODS-SP（5 μm,4.6 mm×250 mm）,organic phase:methanol,mobile phase:20 mmol/L phosphate buffer containing 15 mmol/L β-CD-methanol（85∶15）,flow rate:0.8 mL/min,pH value:5.5,temperature:35 ℃,detection wavelength:305 nm,injection volume:20 μL.Under the optimal conditions,the baseline separation of zopiclone enantiomers was obtained with retention time of 67.42 min and 74.48 min,and resolution of 1.62.The method is simple,sensitive and economic,and could provide a new approach for the further study of zopiclone enantiomers.关键词：high performance liquid chromatography;chiral mobile phase additive;zopiclone;β cyclodextrin;chiral separation
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发布时间： - 摘要：The interactions between alizarin red S(ARS) and bovine serum albumin(BSA) at various pH values were investigated by spectrometry and molecular docking technique.At pH 4.0,the natural compact conformation of BSA was unfolded gradually,which led to the exposure of hydrophobic cavity of domain ⅡA in BSA and decreased the interaction between BSA and ARS.Consequently,the binding constant Kb is only 3.39×104 L?mol-1.However,when the pH value was higher than the isoelectric point(pI 4.8 )of BSA,the interaction between BSA and ARS was enhanced and Kb increased to 3.16×106 L?mol-1 at pH 7.0.Moreover,the effect of surface charges on the interaction of BSA with ARS was not obvious due to the strong hydrogen bonds and van der Waals,forces,which was in accord with the results of molecular docking.关键词：bovine serum albumin;alizarin red S;protein conformation;interaction;pH value
- 2059
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- 1087
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- 4
发布时间： - 摘要：A sensitive high performance liquid chromatography-electrospray tandem mass spectrometric （HPLC-MS/MS） method with dispersive solid phase extraction （DSPE） was developed for the determination of thiacloprid in soil,plant,peanut and peanut hull samples.The extraction solvent,dispersive solid phase extraction sorbents were optimized.The analyte was extracted with acetonitrile containing 0.1% acetic acid,and purified with 50 mg PSA,50 mg C18 and 10 mg GCB dispersive solid phase extraction sorbents.Thiacloprid in the extract was separated by gradient elution using a mobie phase of water-methanol.Qualitative analysis was performed using electrospray ionization in positive ion mode（ESI+） under multiple reaction monitoring （MRM） mode.Matrix-matched calibrations were used to quantify the residue concentrations.The calibration curve was linear in the range of 0.1 -50 μg/kg with correlation coefficients more than 0.996.The recoveries of thiacloprid ranged from 70.6% to 119% at three spiked concentration levels in soil,plants,peanut and peanut hull,with relative standard deviations（RSDs）not more than 16.6%.The limits of quantitation（LOQs） were in the range of 1.0 -5.0 μg/kg.The method could match the requirements for the maximum residue limits （MRLs） in the world.关键词：high performance liquid chromatography-electrospray tandem mass spectrometry;thiacloprid;soil;peanut;dispersive solid phase extraction
- 2371
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- 1055
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发布时间： - 摘要：With the sophistication and variety of microchannels,microfluidic chip which is integrated with multifunctional units including cell loading,culturing,sorting,lysis,separation and detection,not only matches sperm cells in size,but also supplies them with relatively closed growing microenvironments close to physiological level.Some investigations on sperm based on laminar flow and special microchannel geometry were studied.In this paper,the applications of microfluidic chip systems in sperm cell culturing,sorting,intracellular contents analysis and in-vitro fertilization（IVF） were reviewed.Several microfluidic chip systems used to study sperm cell were introduced.Varied sorting methods on sperm cell were also discussed.关键词：microfluidic chip;sperm cell;culturing;sorting;intracellular contents analysis;in-vitro fertilization（IVF）
- 2087
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- 1351
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- 3
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