最新刊期
卷 37 ， 期 4 ， 2018
- 摘要：A fast and direct method was established for the qualitative analysis of triacylglycerols(TAGs) in edible oils using laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry(LDI-FTICR-MS).In the conditions of 45%laser power,100 Hz laser frequency and 100 laser shots,stable and repeatable signals with relative standard deviations(RSDs) less than 10%were obtained via this method.Using MS results and fragmented information,different kinds of edible oils could be directly distinguished from each other.34 different kinds of edible oils were clearly classified by principal component analysis(PCA) and clustering analysis at a confidence level of 95%.5%canola doped in olive could be identified directly using this method.In addition,according to the slopes of linear curves,which kinds of oil was doped in olive oil could be preliminarily predicted.These results indicated that LDI-FTICR-MS had the potential for rapid analyzing and screening edible oils.关键词：laser desorption ionization;FTICR-MS;triacylglycerols;principal components analysis
- 691
- |
- 770
- |
- 2
发布时间： - 摘要：N-(3-fluoro-4-((6-methoxy-7-(3-(4-methylpiperazin-1-yl)propoxy)quinolin-4-yl)oxy)phenyl)-1-(2-fluorophenyl)-4-methyl -5-oxo-4,5-dihydro-1H-1,2,4-triazole-3-carboxamide(LJC-116) is a kind of new Type Ⅱ compounds,c-Met kinase inhibitors with 4-phenoxy quinolone.In vitro experiments showed that they have an excellent anti-tumor activity.In this paper,the in vitro molecular binding interaction between LJC-116 and human serum albumin(HSA) was further investigated by various methods,such as fluorescence spectrometry,synchronous fluorescence spectrometry,fluorescence probe experiments,three-dimensional(3-D) fluorescence spectrometry,ultraviolet-visible(UV-Vis) absorption spectroscopy and molecular docking.It was found that the intrinsic fluorescence of HSA could be quenched by LJC-116 through a static quenching process.The static quenching process was also proved by 3-D fluorescence spectrometry and ultraviolet-visible absorption spectroscopy.The apparent binding constants between LJC-116 and HSA at 288,299，310 K were estimated to be in the order of 104 L·mol-1,which indicated the binding between LJC-116 and HSA was moderate.The thermodynamic parameters ΔH°,ΔG° and ΔS° were calculated,in which the negative ΔG° suggested that the binding of LJC-116 to HSA was spontaneous.Moreover,the positive ΔS° and negative ΔH° revealed that hydrophobic interaction and hydrogen bonds were the major forces to stabilize the protein- LJC-116(1∶1) complex.Under the experimental conditions,the overlapping integral J=7.169 7×10-15 cm3·L·mol-1，R=1.28 nm，r=1.69 nm,E=15.6% were obtained.It indicated a high probability of energy transfer from HSA to LJC-116.Probe agent ibuprofen and warfarin were added in system of HSA-LJC-116,it showed that the primary binding site of LJC-116 was located at site Ⅰ(subdomain ⅡA) of HSA.The slight redshift of fluorescence(0.3 nm),synchronous fluorescence(0.4 nm) and 3-D fluorescence spectra(2 nm) all demonstrated that the polarity of microenvironment for amino acid residues in HSA increased and the hydrophobic property decreased.Finally,the forces deduced from the thermodynamic calculation,and the conformational changes of HSA were validated by the molecular docking.The interaction mechanism of HSA and LJC-116 was comprehensively expatiated at a molecular level in this paper,and some useful information for the transport of Type Ⅱ c-met kinase inhibitors in vivo was provided.关键词：human serum albumin(HSA);c-Met kinase inhibitors;3-D fluorescence spectrum;binding site;molecular docking
- 627
- |
- 844
- |
- 6
发布时间： - 摘要：A ratiometric fluorescent probe MSP,based on Michael addition reaction and intramolecular charge transfer mechanism,was fabricated for the differentiated determination on sulfite and hydrogen sulfide.A strong electron with draw group malononitrile was conjugated to coumarin fluorophore,which activated the electrophilic activity of the C‖C double bond,and strengthened the electron push-pull effect of the probe.As a result,obvious red-shifts in absorption and emission maxima,and great acceleration of the reaction rate between sulfite and the probe could be expected,which enabled MSP to detect sulfite rapidly.As prolonging the assay time to 3 h,the presence of hydrogen sulfide led to obvious blue-shifts in absorption and emission maxima along with significant fluorescence enhancement,and about 260-fold enhancement of the ratio of fluorescence intensities at 510 nm and 690 nm was observed.It is possible to make distinguishment between sulfite and hydrogen sulfide at different response time and different spectral channels.The probe exhibited excellent selectivity and competition toward sulfite and hydrogen sulfide.Good linear relationships between A464/A572 and sulfite,and I510/I690 and hydrogen sulfide over the concentration ranges of 0-200 μmol/L and 0-500 μmol/L were obtained,respectively.The detection limits for sulfite and sulfide were estimated to be 0.95 μmol/L and 0.6 μmol/L,respectively.In addition,the probe could be used for bioimaging sulfite and hydrogen sulfide in living cells.关键词：fluorescent probe;sulfite;hydrogen sulfide;differentiation
- 597
- |
- 778
- |
- 3
发布时间： - 摘要：A method was developed for the determination of 40 organohosphorus pesticides in tea by online gel permeation chromatography/gas chromatography-tandem mass spectrometry(GPC/GC-MS/MS) using multi-walled carbon nanotubes(MWCNTs) as dispersive solid phase extraction(DSPE) sorbent in sample pretreatment.Pesticides residues in tea were extracted with acetonitrile,and cleaned up with MWCNTs.The target compounds were analyzed by the online GPC/GC-MS/MS.The recoveries at three spiked concentration levels of 20,50,150 μg/kg were in the range of 84.2%-109.9% with relative standard deviations(RSDs,n=6) not more than 8.9%.The limits of detection(LODs) were in the range of 0.5-4.6 μg/kg.This method is simple,rapid and sensitive,and could meet the requirements for pesticides analysis.关键词：multi-walled carbon nanotubes(MWCNTs);online gel permeation chromatography/gas chromatography-tandem mass spectrometer(GPC/GC-MS/MS);organophosphorus;tea
- 729
- |
- 701
- |
- 10
发布时间： - 摘要：Nine Schiff-Base substituted 3,5-bis(arylidene)-4-piperidone derivatives,3a-i,were prepared by Claisen-Schmidt condensation reaction,SnCl2/HCl reduction and Schiff-Base condensation reaction.The structures of nine compounds were characterized by FTIR,NMR and elemental analysis.Their antitumor activities against human neoplastic cell lines SGC-7901,A549,HCT116,HeLa,HePG2,K562,THP-1,U937,MCF-7 and their cytotoxicities toward LO2 were subsequently evaluated by MTT method.The results showed that some of them have good antitumor activities,and their IC50 values were lower than 1.0 μmol/L,while the cytotoxicities of 3a,d-f toward LO2 cells were markedly lower than that of DOX.The structure-activity relationships indicated that the antitumor activities of F-substituted 3a-c were better than those of Br- or Cl-substituted 3d-i.Molecular docking model,PCR and Western Blot showed that compounds 3b and 3i could exert obvious inhibition on the active site of Bcl-2 protein.关键词：3,5-bis(arylidene)-4-piperidone;Schiff-Base;antitumor;cytotoxicity;molecular docking
- 646
- |
- 632
- |
- 0
发布时间： - 摘要：An analytical method was developed for the determination of 30 anti-impotence compounds illegally adulterated in health products by ultra high performance liquid chromatography-triple quadrupole mass spectrometry(UHPLC-MS/MS) with a Waters CORTECS T3(100 mm×2.1 mm，2.7 μm) column using 0.1%(by volume) fomic acid aqueous solution-acetonitrile containing 0.1%(by volume) formic acid as mobile phases by gradient elution.The compounds were detected with electrospray ion source in positive mode under multiple reaction monitoring(MRM) mode.The calibration curves for 30 targeted compounds were linear in the mass concentration range of 10-200 μg/L with correlation coefficients more than 0.99.The mean recoveries at spiked levels of 0.1,0.2，1.0 mg/kg were in the range of 62.8%-135.2%,with RSDs(n=6) not more than 14%.The limits of detection(LODs) and the limits of quantitation(LOQs) were 0.05 mg/kg and 0.1 mg/kg,respectively.The established method is accurate and simple,and could be used as a reference for the national standard.关键词：ultra high performance liquid chromatography-triple quadrupole mass spectrometry(UHPLC-MS/MS);illegal adulteration;anti-impotence compounds;health products
- 794
- |
- 733
- |
- 6
发布时间： - 摘要：The sensitive detection of nitrite was carried out by electrocatalytic oxidation with a polyrhodamine/carbon nanotubes composite materials modified glassy carbon electrode(PRhB/CNTs/GCE) as working electrode.The electrochemical behavior and electrocatalytic mechanism of NO-2 ions were investigated at the PRhB/CNTs/GCE through cyclic voltammetry(CV),differential pulse voltammetry(DPV) and amperometry.The results showed that the oxidation potential of NO-2 ions was obviously decreased(124 mV) and the oxidation current was improved 79%at the PRhB/CNTs/GCE in comparison with individual PRhB/GCE,mainly due to the synergistic catalytical effect of polyrhodamine and carbon nanotubes.The electrocatalytical mechamism of nitrite at the PRhB/CNTs/GCE was an irreversible reaction where two electrons involved.High concentration of NO-2 ions were determined by differential pulse voltammetry,and the oxidation current of NO-2 ions was linearly proportional to its concentration in the ranges of 2-25 μmol/L(Ip=94.92cNO-2+0.05,r2=0.992 3)，35-500 μmol/L(Ip=20.32cNO-2+2.65,r2=0.995 8) and 500-8 000 μmol/L(Ip=10.74cNO-2+8.64,r2=0.997 7),respectively.Low concentration of NO-2 ions were detected by amperometry with a linear range of 0.25-5 μmol/L(Ip=0.14cNO-2+0.01,r2=0.993 5).The sensitivity was 143.50 μA·L·mmol-1,and the limit of detection was as low as 0.08 μmol/L.Furthermore,the proposed PRhB/CNTs/GCE exhibited excellent selectivity,good reproducibility,anti-interference property and long-term stability.It was successfully applied in the analysis of nitrite in real water samples,with spiked recoveries of 98.3%- 102.0%.关键词：polyrhodamine B;carbon nanotubes;nitrite;electrochemical detection;chemical modified electrode;electropolymerization
- 718
- |
- 656
- |
- 1
发布时间： - 摘要：A solid phase extraction/liquid chromatography-tandem mass spectrometric(SPE/LC-MS/MS) method was established for the simultaneous determination of 2′-methoxyacetophenone(2′-MAP),2-methoxybenzoic acid(2-MBA),3-phenyllactic acid(3-PA) and 4-hydroxyphenyllactate(4-HPA).The honey sample was dissolved in 1% formic acid solution,then purified with HLB SPE.The separation of the analytes was performed on a Thermo Hypersil Gold C18(50 mm×2.1 mm,1.9 μm) column with 0.1% formic acid solution and acetonitrile containing 0.1% formic acid as mobile phases by gradient elution.The four compounds were detected simultaneously in electrospray negative and positive ionization modes under multiple reaction monitoring(MRM) mode.The results showed that the calibration curves were linear in the range of 0.01-1.0 mg /L for 2′-MAP,2-MBA and 4-HPA,and 0.1-10.0 mg/L for 3-PA with correlation coefficients(r2) higher than 0.99.The limits of detection(LODs) and quantitation(LOQs) were in the ranges of 0.1-1.0 mg/kg and 0.5-5.0 mg/kg,respectively.The average spiked recoveries for honey samples ranged from 79.4% to 98.3% with relative standard deviations(n=6) of 3.2%-8.7%.This method was used to validate 114 hive honey samples from 12 varieties collected in different locations in New Zealand and 50 commercial honey samples from four different countries.With the charateristics of sensitivity,accuracy and rapidness,the method could provid a reference for the identification of monoflower,multiflower and non-manuka honey.关键词：solid phase extraction/liquid chromatography-tandem mass spectrometry(SPE/LC-MS/MS);characteristic compound;manuka honey
- 746
- |
- 633
- |
- 0
发布时间： - 摘要：Three analytical methods were established for the determination of fipronil and its metabolite residues in meat,eggs and visceral nitrile by gas chromatography-mass spectrometry(GC-MS) with electronic ionization(EI) or negative chemical ionization(NCI) and gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS) with EI.And the three methods were compared.The samples were extracted with acetonitrile,and purified with PSA,C18 and GCB.The extracts were determined by GC-MS combined with EI or NCI techniques and GC-MS/MS with EI in multi-reaction monitoring(MRM) mode,and quantified by the external standard method.The calibration curves for fipronil and its metabolites were linear in the range of 0.001-2.0 mg/L with correlation coefficients(r2) higher than 0.999 0.The detection limits(LODs) of GC-MS/EI,GC-MS/NCI and GC-MS/MS/EI were 0.15,0.05,0.15 μg/kg with the limits of quantitation(LOQs) of 0.5,0.2,0.5 μg/kg，respectively.The sensitivity of GC-MS method with NCI is much higher than that with EI when analyzing fipronil and its metabolites with several strong electronegative elements in the molecule.The recoveries at three spiked concentration levels of 2,50,500 μg/kg ranged from 80.0%to 108.0% with relative standard deviations(RSDs) of 1.1%-7.6%.The three methods could complement each other,and be used in the detection and confirmation of fipronil and its metabolites in animal derived foods.关键词：fipronil and metabolite;negative chemical ionization;animal derived foods;GC-MS;dispersive solid phase extraction
- 818
- |
- 676
- |
- 9
发布时间： - 摘要：A method of ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the simultaneous determination of 5 alkaloids residues of opium poppy in hot pot soup,including morphine,codeine,thebaine,papaverine and narcotine.The samples were extracted with acetonitrile containing 0.2% fomic acid,and then analyzed by UPLC-MS/MS.The separation was carried out using a Waters ACQUITY UPLCTM BHE C18(1.7 μm,2.1 mm×50 mm) column by gradient elution with ammonia solution(pH 8.0) and acetonitrile as mobile phases at a flow rate of 0.3 mL/min.The five alkaloids were determined in electrospray positive ionization(ESI+) mode under multiple reaction monitoring(MRM),and the analytes were quantified by the matrix-matched standard solution.Under the optimized detection conditions,the calibration curves are linear in the ranges of 0.25-100 μg/L for morphine and codeine,0.05-100 μg/L for thebaine,and 0.05-10 μg/L for papaverine and narcotinum,respectively,with correlation coefficients all more than 0.999.The limits of detection(LODs) and quantitation(LOQs) were in the ranges of 0.9-4.5 μg/kg and 3.0-15.0 μg/kg,respectively.The average recoveries at the spiked levels of 1，5,10 μg/kg(5，25，50 μg/kg for morphine and codeine) ranged from 70.7% to 109.6%,with relative standard deviations(RSDs) not more than 11%.This method is simple and sensitive,and is suitable for the determination and confirmation of five alkaloids residues of opium poppy illegally added in hot pot soup.关键词：solid phase extraction(SPE);ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);poppy husk;papaverine;morphine;hot pot soup
- 800
- |
- 726
- |
- 5
发布时间： - 摘要：The quantitative nuclear magnetic resonance spectroscopy(qNMR)method for the determination of icariin in Ruzengning capsule was established based on solid phase extraction(SPE).The sample powder in capsule was ultrasonically extracted using 10%alcohol as solvent at room temperature.The extraction solution was enriched and cleaned with an HC-C18 SPE cartridge.The effects of ultrasonic extraction and SPE,qNMR experimental conditions were investigated.The qNMR experiment conditions were selected as follows：using deuterated DMSO as solvent,2,3,5-triiodobenzoate as internal standard,a P1(pulse width)of 14.1 μs,and a NS(number of scan)of 256.The 1H NMR peak of δ 7.9(2,6-H,d,2H)of icariin was chosen as the quantitative peak.Method validation was performed with the intra-day RSD of 0.43%and the inter-day RSD of 0.75%.The linear correlation coefficient(r)was 0.999 9 between the peak area ratio and mass ratio of icariin to internal standard.LOD was 0.122 mg/g and LOQ was 0.368 mg/g.The recoveries of the SPE-qNMR were in the range of 99.8%-103.0%.The result showed that the method was stable,accurate and reliabile.With no need of icariin standard,the method was applied in the determination of icariin in 3 batches of real Ruzengning capsule.关键词：quantitative nuclear magnetic resonance;solid phase extraction;icariin;Ruzengning capsule
- 615
- |
- 661
- |
- 2
发布时间： - 摘要：An analytical method was established for the determination of 15 polycyclic aromatic hydrocarbons(PAHs) in infant formula and rice by high performance liquid chromatography with fluorescence detector(HPLC-FLD).The samples were extracted with acetonitrile,purified by PSA dispersed solid phase extraction,separated on a Waters PAH special column with acetonitrile-water as mobile phase by gradient elution,and detected with the fluorescence detector.These compounds were quantified by the external standard method.Under the optimal conditions,15 PAHs were effectively separated.The linear ranges were 1.0-50 μg/L with correlation coefficients above 0.995.The limits of detection(S/N=3) for 15 PAHs were between 0.05 μg/kg and 0.3 μg/kg.The recoveries were in the range of 86.5% -106.8% with relative standard deviations(n=6) of 0.7%-7.5%.The method was simple and highly sensitive,and was suitable for the determination of polycyclic aromatic hydrocarbons in infant formula and rice.关键词：polycyclicaromatic hydrocarbons(PAHs);infant formula;infant rice;high performance liquid chromatography;fluorescence;dispersive solid phase extraction
- 761
- |
- 722
- |
- 7
发布时间： - 摘要：An ultra-performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was established for the determination of thirteen sex hormones in cosmetics.Toner,oil,cream and mask cosmetic samples were extracted with 50% acetonitrile by vortex,and separated on a C18 column．The analysis was performed under dynamics multiple reaction monitoring(DMRM) mode.The results showed that the limits of detection(LODs) for 13 sex hormones in various kinds of cosmetics were in the range of 0.001-0.026 μg/g.Good linear relationship existed between peak area and mass concentration of 0.89-64.80 μg/L with correlation coefficients higher than 0.995.The average recoveries were in the range of 80.8%-116.8%,with relative standard deviations(RSDs,n=6) of 0.7%-14.4%.With the advantages of high efficiency,sensitivity and accuracy,this method fills the gaps of determining chlormadinone acetate and other sex hormones,and is suitable for the general detection of neutral sex hormones in cosmetics.关键词：UPLC-MS/MS;cosmetics;sex hormones
- 691
- |
- 646
- |
- 8
发布时间： - 摘要：A method for the rapid determination of specific migration(SM) of methylparaben,ethylparaben,isopropylparaben and propylparaben in food simulants(10%ethanol,3%acetic acid,20%ethanol,50%ethanol and olive oil) was developed by HPLC-UV detection with organic phase anion exchange(OPAE) solid phase extraction(SPE).After the migration test,the soaking solution was cooled down,and vortexed.The olive oil food simulant sample was pretreated by organic phase anion exchange solid phase extraction before injection,while the aqueous food simulant(10%ethanol,3%acetic acid,20%ethanol or 50%ethanol solution) sample was just filtered through a polytetrafluoroethylene filter with a disposable syringe before injection.The baseline separations for four parabens were achieved within 12.5 min on a phehyl column.The external standard method for calibration curve was adopted via ultraviolet detector.The linearities of the method for 4 parabens were good with r2≥0.999 8 over the concentration range of 0.5-100 mg/L.The recoveries for 4 parabens in 5 types of food simulants at spiked levels of 10,50,100 mg/kg were between 97.9%and 103%with relative standard deviations of 0.02%-2.2%.The limits of quantitation of the method were between 0.1 mg/kg and 0.5 mg/kg.With the low limits of quantitation,good recoveries and accuracies,the method could meet the requirements of (EU)NO 10/2011 regulation for the specific migration limit of four parabens.The method was applied in the analysis of food contact material samples.关键词：OPAE;SPE;HPLC-UV;methylparaben;ethylparaben;isopropylparaben;propylparaben;specific migration
- 741
- |
- 687
- |
- 0
发布时间： - 摘要：An UPLC-MS/MS method was developed for the quantification of afatinib and paclitaxel in rat plasma.The method was also applied in the investigation on the pharmacokinetics of the analytes.The plasma samples were extracted by solid-phase extraction(SPE),and seperated on an Agilent Zorbax Eclipse Plus C18(100 mm×2.1 mm，1.8 μm) column with acetonitrile and water containing 0.1% formic acid as mobile phases at a flow rate of 0.4 mL/min,a column temperature of 40 ℃ and a sample injection of 3 μL.The quantification analysis was performed by MS with positive electrospray ionization(ESI+) source in multiple reaction monitoring(MRM) mode.The calibration curves for two analytes were linear over the concentration range of 0.5-1 500 μg/L,with correlation coefficients(r2) of 0.998 and the lower limits of quantitation(LLOQs) of 0.5 μg/L.The inter-day RSDs and intra-day RSDs were not more than 8.4%,and the accuracy ranged from 92.5% to 107.1%.The average recoveries were in the range of 86.2%-95.1%.The matrix effect values were sufficiently minimized to 86.6%-108.6%.The validated method is rapid and sensitive.It could be applied in the determination of afatinib and paclitaxel in plasma,and provide an analysis means for the clinical medication adjustment.关键词：afatinib;paclitaxel;UPLC-MS/MS;quantification analysis;pharmacokinetics
- 778
- |
- 681
- |
- 0
发布时间： - 摘要：A method for the simultaneous determination of roxarsone(ROX),arsanilic acid(ASA),naphthalene arsenate(NPAA),carbarsone(CBS),arsenate(As Ⅴ),arsenite(As Ⅲ),methyl arsenic acid(MMA),dimethyl arsenic acid(DMA),arsenobetaine(As B) and arsenic choline(As C) was developed by high performance liquid chromatography and inductively coupled plasma mass spectrometry(HPLC-ICP-MS).The sample was extracted with 10% methanol.The HPLC separation was performed on a Dionex IonPac AS7 anion exchange column with ammonium carbonate as mobile phase by gradient elution.Identification and quantification were achieved by ICP-MS.The linear ranges for ten arsenic species compounds were observed from 0.1 μg/L to 100 μg/L with correlation coefficients greater than 0.999.The detection limits of ten arsenic species were in the range of 0.3-1.5 μg/kg and the limits of quantitation were 1.0-5.0 μg/kg.The average recoveries for ten arsenic species spiked at three levels ranged from 81.3% to 97.7% with relative standard deviations of 0.1%-3.5%.With good reproducibility,high sensitivity,the method could extract ten arsenic species in only 5 min with organization grinding oscillation,which was much simpler and more efficient than that with conventional water bath oscillation.The method is suitable for the simultaneous determination of ten arsenic species in chicken and chicken liver.ASA and As Ⅲ were checked out in actual chicken liver samples.关键词：HPLC-ICP-MS;chicken;chicken liver;arsenic speciation
- 621
- |
- 600
- |
- 4
发布时间： - 摘要：A novel method was developed for the detection of HbAlc using a screen printed electrode with 3-aminophenylboronic acid modified magnetic nanoparticles.The magnetic nanoparticles modified with 3-aminophenylboronic acid were prepared,which could bind with glyeosylated hemoglobin(HbA1c) and be separated from hemoglobin when the sample is injected into the reticulated vitreous carbon(RVC) flow cell.A screen printed electrode was fabricated by the reaction of chitosan(CS),tetraenthoxyl silica(TEOS) and carbon nanotubes to form a sol-gel layer at the surface of the electrode.Based on this,a novel electrochemical method was developed for the detection of HbA1c.There were good relationships of electric charge at the screen printed electrode with concentrations of HbA1c and Hb under the potential of 0.10 V, and the limits of detection were 6 mg/mL and 0.05 mg/mL，respectively.With simple preparation,good reproducibility and stability,the method could effectively eliminate the interference of AA and UA.It was successfully applied in the detection of HbA1c in real samples.关键词：3-aminophenylboronic acid;screen printed electrode;magnetic nanoparticles;HbA1c
- 730
- |
- 617
- |
- 1
发布时间： - 摘要：Proton nuclear magnetic resonance(qHNMR) and fluorine nuclear magnetic resonance(qFNMR) were employed to determine the content of risperidone.The 1H NMR spectra were collected at 300 K within 4.0 s acquisition time,15 s relaxation delay and 32 scanning times.Proton signal peaks at δ 7.29-7.35 of risperidone and δ 6.02 of maleic acid were served as quantitative peaks.The 19F NMR spectra were obtained at 300 K by using 12 500.0 Hz spectral width and -43 662.7 Hz transmitter frequency offset(O1).4-bromo-2-fluorine acetanilide was employed as the internal standard.The results of qHNMR and qFNMR were generally consistent with that of the mass balance method.Therefore,quantitative nuclear magnetic resonance could be used for the quantitative determination of risperidone.关键词：risperidone;nuclear magnetic resonance;1H NMR;19F NMR
- 774
- |
- 652
- |
- 6
发布时间： - 摘要：The photoelectrochemical sensors,with light as excitation source and photocurrent or photovoltage as detection signal,have been widely used in the analysis of environment,food,medicine and other fields for their characteristics of fast response,high sensitivity and simple equipment.The preparation,principles and classification of photoelectrochemical sensors are introduced.They include light addressing potentiometric sensors and amperometric photoelectrochemical sensors,in which amperometric photoelectrochemical sensors are widely used due to their excellent photoelectric performance,low detection limit,low cost and easy processing.Their applications in the fields of metal ions,organic pollutants,nucleic acids,proteins and cells are described in this manuscript.The development prospect for photoelectrochemical sensors is also expected.关键词：photoelectrochemical;sensor;photoelectric material;application;research progress
- 709
- |
- 776
- |
- 5
发布时间： - 摘要：Squalene is a small molecular lipid with functional activity,which exists in animals,plants and microorganism,and possesses wide bioactivities such as anti-oxidation,preventing cancer,anticancer,anti-radiation,oxygen-carrying,skin moisturizer and inhibiting microbial growth etc.Thus,squalene is extensively applied in the development of functional food,cosmetics and pharmaceutical products.Analysis on squalene content in different foods has always been the focus of domestic and foreign scholars.The sample pretreatment methods for squalene in different foods are mainly summarized in this review,including supercritical carbon dioxide extraction,solid phase extraction,solid phase microextraction,saponification extraction,organic solvent extraction and fractional crystallization etc.Meanwhile,the application and development of detection methods for squalene,such as gas chromatography,liquid chromatography and gas chromatography-mass spectrometry etc.,are also reviewed in order to provide a reference for analysis of squalene in food.关键词：squalene;foods;sample pretreatment;detection method;review
- 593
- |
- 599
- |
- 2
发布时间：
- Address：100 Xianlie Middle Road, Guangzhou Postal code：510070
- Tel：020-87684776,37656606 Fax：020-87684776 Email：fxcsxb@china.com
- Technical support is provided by Beijing Founder electronics co., LTD 粤ICP备12017312号-3
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0