最新刊期
卷 39 ， 期 4 ， 2020
- 摘要：A liquid chromatography-tandem mass spectrometric(LC-MS/MS) method with QuEChERS and solid phase extraction(SPE) cleanup was developed for determination of 27 novel fentanyl analogs and metabolites in solid and liquid drugs.The confirmation was achieved with electrospray ionization(ESI) in positive ion mode under multiple reaction monitoring(MRM) mode,and quantified by the external standard method.The standard curves for 27 target compounds were linear in the range of 0.5-50.0 μg/L,with their correlation coefficients(r2) more than 0.99.The limits of quantitation(LOQ) were 10.0 μg/kg for solid drugs and 10.0 μg/L for liquid drugs,respectively.Recoveries at three spiked levels ranged from 84.8% to 109% with relative standard deviations(RSD) of 0.86%-8.5%.With the advantages of rapidness,simplicity,time saving,high sensitivity and good stability,the method could be applied in the qualitative and quantitative detection of fentanyl analogs and metabolites in drugs.关键词：QuEChERS;liquid chromatography-tandem mass spectrometry(LC-MS/MS);fentanyl analogs and metabolites;solid phase extraction
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发布时间：2023-04-18 - 摘要：Current manual sampling and analysis methods,such as refractive index measurement,chromatography,etc.,have complex operations,time lags and human errors.Therefore,they cannot be used to evaluate the esterification process in polyester production in real time and determine the clear point of the reaction.In this article,an online Raman analysis system with 1 064 nm as the laser wavelength was set up to collect continuously the spectra of the esterification reaction between terephthalic acid(PTA) and 1,3-propanediol(PDO) to create poly(tri methylene terephthalate)(PTT),while using Savitzky-Golay algorithm to make baseline correction on the collected spectra.The principal component analysis was used to extract the spectral information.Based on the principle of esterification process,a qualitative analysis method was established to determine the clear point by using the area ratio for Raman characteristic peaks of benzene loop located near 1 604 cm-1 and ester group located at 1 720 cm-1.Results showed that the developed Raman spectroscopy could accurately reflect the clear point in the esterification process of polyester prodction,With the advantages of good real time performance,simple operation and rapid analysis,it provides a reference for the process control and product quality control of polyester production.关键词：Raman spectroscopy;polyester;online detection;qualitative analysis;fluorescence suppression
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发布时间：2023-04-18 - 摘要：A high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was developed for the simultaneous determination of 31 alkaloids in essential oil cosmetics.A mixture of methanol-H2O(3∶1,by volume) containing 2% formic acid solution was selected as extracting agent.Meanwhile,n hexane was adopted for defatting treatment.The chromatographic separation was performed on an HPH-C18 column(2.7 μm，100 mm×2.1 mm) by gradient elution,with water containing 0.2% formic acid-acetonitrile as mobile phases at a flow rate of 0.35 mL/min.The 31 alkaloids were analyzed in positive electrospray ionization mode under multiple reaction monitoring(MRM) mode.Results showed that there were good linear relationships for the analytes in corresponding concentration ranges,with their correlation coefficients(r) of 0.992 8-1.000 0.The limits of detection(LOD) and limits of quantitation(LOQ) of the method were in the ranges of 0.09-3.03 μg/kg and 0.31-1012 μg/kg,respectively.The recoveries at three spiked levels ranged from 63.3% to 126%,with relative standard deviations(RSD) of 0.73%-17%.The method was rapid,accurate and sensitive,and was suitable for the detection of alkaloids in cosmetics and evaluation of safety of cosmetics.关键词：alkaloids;high performance liquid chromatography-tandem mass spectrometry;essential oil cosmetics
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发布时间：2023-04-18 - 摘要：An ultra performance liquid chromatography-quadrupole time of flight mass spectrometric(UPLC-Q-TOF-MS) method was established for the identification of chemical constituents in the extract of Eurycoma longifolia Jack.The sample was separated on an Agilent Eclipse Plus-C18 RRHD(2.1 mm×100 mm,1.8 μm) column with acetonitrile and 0.1% formic acid water as mobile phases by gradient elution.The data were collected with electrospray ionization in positive mode.According to the contrast of the reference standards and the accurate masses of molecules,a total of 49 compounds in Eurycoma longifolia Jack extract were identified,including 29 quassinoid diterpenoids,4β-carboline alkaloids,12 canthin-6-one alkaloids,3 biphenyl-neolignans and 1 squalene triterpene.The method was accurate,reliable and efficient,and could comprehensively reflect the chemical constituents of Eurycoma longifolia Jack,and provided a reference for further elucidating its pharmacological basis and quality controll.关键词：Eurycoma longifolia Jack;ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS);qualitative analysis;quassinoid diterpenoids;β-carboline alkaloids;canthin-6-one alkaloids
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发布时间：2023-04-18 - 摘要：In this paper,the positional isomers of monocaffeoylquinic acid and dicaffeoylquinic acid were separated and analyzed by liquid chromatography(LC),then analyzed by tandem mass spectrometry(MS/MS) with different collision energies.The fragmentation rules for the analytes were investigated using MS/MS.For the positional isomers of monocaffeoylquinic acid,as the intensities of their parent ion 377 and product ion 163 changed significantly under different collision energies,they could be distinguished by the intensity ratios of 377/163.The isomers with intensity ratios of 377/163 in turn were 3-O-caffeoylquinic acid,4-O-caffeoylquinic acid and 5-O-caffeoylquinic acid.As for the positional isomers of dicaffeoylquinic acid,the intensities of their parent ion 539 and product ions 377 and 163 changed significantly under different collision energies,they could be distinguished by their intensity ratios of 539/377 and 377/163.The isomers with intensity ratios of 539/377 in turn were 4,5-di-O-caffeoylquinic acid,3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid,while the isomers with intensity ratios of 377/163 in order were 3,5-di-O-caffeoylquinic acid,4,5-di-O-caffeoylquinic acid and 3,4-di-O-caffeoylquinic acid.The positional isomers of caffeoquinic acid were separated and analyzed based on an Agilent Poroshell 120 SB-Aq C18 column,and the eluting orders were as follows:5-O-caffeoylquinic acid,4-O-caffeoylquinic acid,3-O-caffeoylquinic acid,3,4-di-O-caffeoylquinic acid,3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid.The positional isomers of caffeoylquinic acid in honeysuckle were identified accurately based on the chromatographic retention and MS/MS characteristics.关键词：monocaffeoylquinic acid;dicaffeoylquinic acid;positional isomers;liquid chromatography-tandem mass spectrometry(LC-MS/MS);ion intensity ratio
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发布时间：2023-04-18 - 摘要：In this paper,a gas chromatography-ion mobility spectrometry(GC-IMS) was developed for the detection of volatile organic compounds(VOCs) in 81 subjects,including 20 patients with pulmonary cryptococcosis,28 patients with pulmonary aspergillosis as patient controls and 33 healthy controls.Analysis of a single sample took only 10 minutes.A total of 19 VOCs were detected.By principal component analysis(PCA),it was found that there was a clear distinction between the exhaled VOCs of patients with pulmonary cryptococcal disease and those of healthy controls,while the difference between the exhaled VOCs of pulmonary cryptococcal patients and that of pulmonary aspergillosis patients was not so significant.Furthermore,the potential characteristic VOCs for patients with pulmonary cryptococcal disease screened by OPLS-DA(orthogona partial least squares-discrimination analysis) model included 2-methyl-1-propanal,isopropyl benzene,2-pentanone,4-methyl-2-pentanone,butanal and hexanal,while those for pulmonary aspergillosis patients were 2-butanone,2-pentanone,isopropyl benzene,2-methyl-1-propanal,4-methyl-2-pentanone and 3-pentanone.Therefore,it could be found that the characteristic VOCs of patients with pulmonary cryptococcal and pulmonary aspergillosis diseases both included 2-methyl-1-propanal,isopropyl benzene,2-pentanone and 4-methyl-2-pentanone.It can be concluded that butanal and hexanal were more specific in pulmonary cryptococcal patients,while 2-butanone and 3-pentanone were more specific in pulmonary aspergillosis patients.In summary,the GC-IMS method was rapid in the analysis of exhaled VOCs of pulmonary cryptococcal patients,and it could be used in the analysis for hundreds or even thousands of samples,providing the necessary basic data for objective evaluation on the feasibility of pulmonary cryptococcal diagnosis.关键词：pulmonary cryptococcal;VOCs;breath diagnosis;GC-IMS
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发布时间：2023-04-18 - 摘要：A method of high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was developed for the determination of nine pyrrolizidine alkaloid residues in animal derived foods.Honey,dairy and animal liver samples were dissolved with 0.05 mol/L hydrochloric acid,5% trichloroacetic acid and acetonitrile containing 1% acetic acid,respectively,then enriched and purified with a strong cationic solid phase extraction column(Waters Oasis MCX).The separation was carried out on a Phenomenex Kinetex C18 column(4.6 mm×100 mm,2.6 μm) by gradient elution with methanol-0.1% formic acid-5 mmol/L ammonium acetate as mobile phase.The separated compounds were detected in positive electrospray ionization(ESI+) under multiple reaction monitoring(MRM) mode.The calibration curves for 9 alkaloids were linear in the mass concentration range of 0-100 ng/mL with correlation coefficients(r) larger than 0.99.The average recoveries at there spiked levels of 10,20 and 50 μg/kg ranged from 71.0% to 103%,with relative standard deviations(RSD) of 3.0%-9.8%.The limits of detection and limits of quantitation(LOQs) of the method were 3 μg/kg and 10 μg/kg,respectively.The method is simple,rapid and accurate,and is suitable for the simultaneous determination of pyrrolizidine alkaloids in animal derived foods.关键词：animal derived food;pyrrolizidine alkaloids;solid phase extraction;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）
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发布时间：2023-04-18 - 摘要：A high performance liquid chromatography-mass spectrometric(HPLC-MS) method was developed for the determination of bovine typeⅠ collagen.Collagen sponge samples were digested with trypsin,then the digesting mixture was separated with a C18 column.The detection was performed with electrospray ionization in positive mode and using single ion monitoring(SIM) mode for data collection,and the quantitation was achieved by external standard method.A marker peptide GFSGLDGAK was obtained in the tryptic digestion of bovine typeⅠ collagen.There was a good linearity for the marker peptide in the concentration range of 0.645-21.5 μg/mL(r2=0.999 4).The quantitation limit of the method was 6.45×10-4 μg/mL.Recoveries for the target at three spiked levels of 3.10,2.48 and 1.55 μg/mL ranged from 98.2% to 102%,with relative standard deviations(n=6) of 0.80%.The collagen sponge samples were tested for uniformity,stability and constant value to ensure the effectiveness of the method and the quality of the product,and the content of bovine typeⅠ collagen was determined to be （0.926±0.014） mg/mg.The method is simple,rapid,replicable and high stable,and could meet the requirements for determination of bovine typeⅠ collagen.关键词：high performance liquid chromatography-mass spectrometry(HPLC-MS);marker peptide;bovine typeⅠ collagen;quantitation
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发布时间：2023-04-18 - 摘要：A method of ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was established for the simultaneous determination of 115 pesticides in blood.The blood sample and the extractant methanol were mixed at a volume ratio of 1∶5,vortexed for 2 min,centrifuged at 12 000 r/min for 10 min,and thesupernatant was taken for UPLC-MS/MS analysis.Scheduled multiple reaction monitoring in both electrospray ionization positive ion mode(ESI+) and negative ion mode(ESI-) were adopted in MS analysis.Results showed that there were good linear relationships for 115 target pesticides in the concentration range of 1-200 ng/mL with their correlation coefficients(r) larger than 0.99.The limits of detection(S/N≥3) were 0.2 ng/mL for 13% of the target pesticides and 0.1 ng/mL for the rest of pesticides.The limits of quantitation(S/N≥ 10) for all the target pesticides were 1 ng/mL.At the spiked levels of 10,50 and 100 ng/mL,the matrix effects of the method were between 81.8% and 115%.The recoveries for the target pesticides ranged from 80.4% to 109%,with intra-RSDs and inter-RSDs of 1.6%-11% and 1.9%-13%,respectively.The method was simple,rapid,sensitive and stable,and was suitable for the qualitative and quantitative analysis of multi pesticide in blood samples.关键词：ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS;blood;pesticide
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发布时间：2023-04-18 - 摘要：A gas chromatography-mass spectrometry(GC-MS) with ultrasonic assisted dispersive liquid-liquid microextraction(UA-DLLME) was developed for the simultaneous determination of 15 nitroaromatics,19 anilines and 14 Phthalates in ground and surface water samples.A Plackett-Burman design was adopted for screening of variables such as extractant,disperser volume,extraction temperature,extraction time and ionic strength in order to determine the significant variables affecting the extraction efficiency,which were then optimized by using a central composite design(CCD) and the response surface equations.The optimum experimental conditions were as follows:10 mL water sample containing 2 g/L NaCl was rapidly injected with 0.65 mL acetonitrile(disperser) and 40 μL CCl4(extractant),then ultrasonically extracted for 2 min at 40 ℃ and followed by a centrifugation at 3 500 r/min for 3 min.Results showed that there were good linear relationships for the target compounds in the concentration range of 1.0-200 μg/L with their correlation coefficients(r) not less than 0.995 8.The limits of detection(LODs) and limits of quantitation(LOQs) of the method were in the ranges of 0.001-0.030 μg/L and 0.004-0.120 μg/L,respectively.The average recoveries at low,middle and high spiked levels ranged from 77.4% to 113%,with the relative standard deviations(RSDs,n=6) not more than 9.6%.关键词：nitroaromatics;gas chromatography-mass spectrometry(GC-MS);central composite design(CCD);ultrasonic assisted dispersive liquid-liquid microextraction(UA-DLLME)
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发布时间：2023-04-18 - 摘要：A multi-residue analysis method was developed for the determination of 41 kinds of pesticides in ginseng by gas chromatography-tandem mass spectrometry(GC-MS/MS) with QuEChERS.The samples were extracted using three QuEChERS methods,ie.original,acetate and citrate,respectively.The final extracts were evaluated by GC-MS/MS in selected reaction monitoring(SRM) mode,and quantified by external standard method.The extraction efficiency and purification effect of the three methods were investigated.Results showed that when the original QuEChERS method was selected,which was the most suitable for the tested pesticides,there were good linear relationships for the 41 pesticides in a certain concentration range,with their correlation coefficients(r) higher than 0.995.The limits of detection(LODs,S/N=3) and the limits of quantification(LOQs,S/N=10) of this method were between 2.0-6.0 μg/kg and 5.0-20.0 μg/kg,respectively.Recoveries at four spiked levels of 10,20,100 and 200 μg/kg ranged from 86.7%-115% with the relative standard deviations(RSDs) less than 15%.The method is simple,effective,accurate and sensitive,and is applicable for the screening and detection of multi pesticide residues in ginseng.关键词：QuEChERS;gas chromatography-tandem mass spectrometry(GC-MS/MS);multi pesticide residues;ginseng
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发布时间：2023-04-18 - 摘要：A novel high performance liquid chromatography(HPLC) with dispersive liquid-liquid microextraction based on vortex assisted solidification of floating deep eutectic solvent(VA-DLLME-SFDES) was established for the determination of triclosan and triclocarban in water samples.Six hydrophobic deep eutectic solvents(DESs) were newly synthesized,which physical and chemical constants such as density,melting point and octanol-water partition coefficient(KOW) were determined.One of the low density DES with suitable freezing point was selected as the micro-extractant.After vortex assisted extraction and freezing,the extractant was solidified and attached to the inner wall of the centrifuge tube.After removing the aqueous phase,the DES was melted and centrifuged in room temperature,and followed by HPLC analysis.The optimum extraction conditions were as follows：DES prepared with menthol-1 dodecanol(1∶2,molar ratio) as extraction solvent,volume of extraction solvent：70 μL,pH of water sample：5.0,vortex time：1 min.Under the optimum conditions,there were good linearities for triclosan and triclocarban in the concentration ranges of 0.59-100 μg/L and 0.26-100 μg/L,respectively,with their correlation coefficients(r2) of 0.999 8 and limits of detection(S/N=3) of 0.08-0.18 μg/L.The enrichment factors for the analytes varied from 141 to 148.Meanwhile,the recoveries were in the range of 86.0%-115% with intra-precision(n=6) and inter-precision(n=6) not more than 5.4%.The method is simple,rapid and easy in collecting the extraction phase,and it is suitable for the determination of triclosan and triclocarban in water.关键词：hydrophobic deep eutectic solvent;solidification of floating organic droplet;dispersive liquid-liquid microextraction;lake water;triclosan;triclocarban
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发布时间：2023-04-18 - 摘要：kind of novel fluorescence carbon quantum dots(CDs) were fabricated by microwave heating method using L aspartic acid and urea as the precursors.The obtained CDs exhibited good spherical shapes with an average size about 5 nm.In addition,the CDs were characterized by Fourier transform infared spectroscopy,X-ray photoelectron spectroscopy,ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy.The CDs showed high fluorescence stability,good particle dispersion,excellent water solubility and remarkable selectivity toward isorhamnetin(ISOR).Under the optimized conditions,there was a good relationship between fluorescence quenched degree(IF0/IF) of the CDs and concentration of ISOR in the range of 0.22-180 nmol/L with a limit of detection(LOD) of 1.32 nmol/L.The CDs were successfully applied in the detection of ISOR in ginkgo biloba tablets with recoveries of 90.8%-107%.Results showed that the as synthesized CDs could be used in ISOR detection with rapidness,efficiency and sensitivity.关键词：L-aspartic acid;urea;carbon quantum dots(CDs);isorhamnetin;quench
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发布时间：2023-04-18 - 摘要：A gas chromatographic(GC) method based on QuEChERS extraction salt package and solid phase extraction was established for the determination of 19 pesticides residues,i.e.bifenthrin,fenpropathrin,permethrin,cypermethrin,fenvalerate,deltamethrin,dichlorvos,methamidophos,acephate,diazinon,dimethoate,pirimiphos-methyl,chlorpyrifos,fenitrothion,profenofos,fipronil,fipronil-desulfinyl,fipronil sulfide and fipronil sulfone in eggs.The sample was extractd with acetonitrile and QuEChERS extraction salt package,and then purified with GCB adsorbent and C18 SPE.The analytes were separated on an Agilent DB-1701(30 m×0.32 mm,0.25 μm) polarity capillary column,then detected by GC with FPD detector and ECD detector,and quantified by external standard method.Results showed that there were good linear relationships for 19 pesticides in their respective concentration ranges,with correlation coefficients(r2) not less than 0.999 3.The recoveries at three spiked levels of low,meddle and high ranged from 78.6% to 105%,with relative standard deviations(n=6) of 1.6%-93%.The limits of detection(LOD,S/N=3) and limits of quantitation(LOQ,S/N=10) were in the ranges of 0.138-8.33 μg/kg and 0.461-27.8 μg/kg,respectively.With the advantages of simplicity,good separation,reliability and stability,the established method could meet the requirements for determination of pesticides multi residues in eggs.
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发布时间：2023-04-18 - 摘要：An analytical method was established for the determination of the main corrosive sulfide,dibenzyl disulfide(DBDS) in transformer insulating oil by high performance liquid chromatography(HPLC) with vortex assisted liquid-liquid microextraction(VA-LLME).Under the optimized conditions,the DBDS was quantified by external standard method and internal standard method with acetonitrile as extractant.Results showed that there were good linear relationship for DBDS in the concentration range of 0.1-600.0 mg/kg with correlation coefficients(r) more than 0.999.The limits of detection(LOD,S/N=3) were in the range of 6.9-7.1 μg/kg.The method was applied in the determination of target analytes in commercial transformer oil samples and aging oil samples.The recoveries were in the range of 95.0%-112% with relative standard deviations(RSD) not more than 2.3%.The method has the characteristics of high efficiency,high sensitivity and environmental friendliness,and has no significant difference with the GC-ECD method of IEC 62697 in USA and GC-MS method of GB/T 32508 in China.It also provides references for the standards revision of quantitative detection of corrosive sulfide DBDS in transformer oils in China.关键词：dibenzyl disulfide(DBDS);liquid-liquid microextraction;high performance liquid chromatography(HPLC);transformer oil;corrosive sulfide
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发布时间：2023-04-18 - 摘要：An analytical method of hydrophilic interaction chromatography with indirect ultraviolet detection was developed for the determination of tetrabutylphosphorus and tetrabutylammonium using ionic liquids as mobile phase additives.Effects of imidazolium ionic liquids,pyridinium ionic liquids,organic solvents,detection wavelengthes and other factors on the determination of tetrabutylphosphorus and tetrabutylammonium were investigated.The roles of ionic liquids were discussed.The separation and detection of tetrabutylphosphorus and tetrabutylammonium were achieved within 15 min on a hydrophilic interaction chromatographic column at 30 ℃,with acetonitrile-1.0 mmol/L 1-ethyl-3-methylimidazolium tetrafluoroborate(60∶40,by volume) as mobile phase at a flow rate of 1.0 mL/min,and the ultraviolet detection wavelength was set at 210 nm.The limits of detection for the analytes were in the range of 1.0-1.2 mg/L.The linearity and reproducibility of the method were good.The method was applied in the analysis of Songhua River water samples and Keyin River water samples with the spiked recoveries between 95.9% and 107%.This method is simple and easy to use.关键词：ionic liquids;hydrophilic interaction chromatography;tetrabutylphosphorus;tetrabutylammonium;indirect ultraviolet detection
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发布时间：2023-04-18 - 摘要：A rapid liquid chromatography-tandem mass spectrometric(LC-MS/MS) method was developed for the determination of enramycin in swine liver.The swine liver samples were extracted twice with 0.1 mol/L hydrochloric acid solution-acetonitrile(3∶7,by volume),then purified by liquid-liquid extraction with ethyl acetate and hexane after centrifugation,and finally analyzed by LC-MS/MS after dilution with 0.1% formic acid solution.The separation was performed on an Acquity BEH C18 column(100 mm×2.1 mm，1.7 μm) with 0.1% formic acid solution-methanol as mobile phase by gradient elution.The LC-MS/MS analysis was in a positive electrospray ionization(ESI+) mode with multiple reaction monitoring(MRM) acquisition,and matrix matched external standard method was used for quantitation.Results showed that there existed good linear relationships for enramycin A and enramycin B in the range of 2.0-500 μg/L.The limits of detection for enramycin A and enramycin B were 3.0 and 4.0 μg/kg,and the limits of quantitation for them were 10 and 12 μg/kg,respectively.At the spiked levels of 15-60 μg/kg,the recoveries ranged from 80.8% to 90.3% with intra-assay relative standard deviations of 0.90%-4.5% and inter-assay relative standard deviations of 3.0%-4.3%.Compared with the other LC-MS/MS methods,the method is more suitable for the determination of enramycin in animal liver tissues due to its simplicity and reliability.关键词：swine liver;enramycin;liquid chromatography-tandem mass spectrometry;residue
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发布时间：2023-04-18 - 摘要：A gas chromatography-mass spectrometric method with thermal separation injection was developed for the rapid detection of 4 fatty acid ethyl esters,i.e.palmitic acid ethyl ester,linoleic acid ethyl ester,oleic acid ethyl ester and stearic acid ethyl ester in olive oil.The target compounds were volatilized at appropriate inlet temperature,separated on a DB-5MS column,and detected in selected-ion monitoring mode.Results showed that the standard curves for 4 analytes were linear over the concentration range of 0.01-0.20 mg/L,with correlation coefficients(r2) greater than 0.999.The limits of detection(LODs) and limits of quantitation(LOQs) of the method were 0.3 mg/kg and 1.0 mg/kg,respectively.Recoveries at three levels of 1.0,2.0 and 10 mg/kg ranged from 82.4% to 109%,with relative standard deviations of 0.68%-6.8%.The method is sensitive,accurate and stable,and is suitable for the rapid detection of 4 fatty acid ethyl esters in olive oil.关键词：thermal separation injection;gas chromatography-mass spectrometry;olive oil;fatty acid ethyl esters
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发布时间：2023-04-18 - 摘要：Control of elemental impurities has always been an important issue in the research and development for drugs.Some elemental impurities may not only adversely affect the stability and shelf life of a drug,but also cause side-effects of the drug due to its potential toxicity.The European Union and the United States are increasingly stricter on the control of elemental impurities.New requirements in USP<232>,USP<233> and ICH Q3D have been put forward for the classification and control of elemental impurities.Therefore,the detection for this item after Chinas entry into the ICH should also be closer to that of the international community,ant it is especially important to establish an effective testing method.In this paper,the recent progress in the analysis techniques for elemental impurities in drugs is introduced from the aspects of sample preparation,rapid screening and instrumental analysis,anticipating to provide a theoretical support and a technical reference for the analysis of elemental impurities in pharmaceuticals.关键词：drug;elemental;impurities;analytical techniques;review
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发布时间：2023-04-18 - 摘要：Design and development of fast,reliable,cheap and high throughput DNA sequencing could be the most revolutionary significance for preventing early disease and understanding the mechanisms of related diseases.Due to its distinctive structures and properties,the new nanomaterials graphene is playing an important role in many areas such as chemistry and bioscience.In this review,we describe the research states of DNA sequencing and the advantages of the application of graphene nanomaterials.The different current signals generated by DNA chains through graphenenanopore,graphenenanogap and graphene nanoribbon to identify base sequences are discussed in detail.The effect of interaction between DNA chains and graphene on DNA sequencing isfurther discussed,and the future research of DNA sequencing is also prospected.It provides referencesof working principle,theoretical research and detection methods of DNA sequencing based on graphene nanomaterials.关键词：DNA sequencing;graphene;nanopores;nanogaps;nanoribbons;reviewDNA
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发布时间：2023-04-18
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