最新刊期
卷 37 ， 期 3 ， 2018
- 摘要：In this paper,a method was developed for the detection of characteristic VOCs in exhaled breath of lung cancer patients by proton transfer reaction mass spectrometry(PTR-MS).An improved breath analysis system was used for 32 normal volunteers and 40 lung cancer patients.The data were statistically analyzed by Mann-Whitney test and logistic regression.The results showed that analytes VOC 33，VOC 39 and VOC 45 might be the breath markers for lung cancer patients,while VOC 45 was significantly different between patients with small cell lung cancer and non-small cell lung cancer.The area derived from the receiver operating curve(AUC),under the logistic regression model,reached to 0.878,with the sensitivity and specificity of 85.5% and 63.5%,respectively,while through the Fisher discriminant model,the area from AUC reached to 0.822,with sensitivity and specificity of 82.5% and 62.5%,respectively.The two models were both statistically significant for lung cancer prediction.关键词：lung cancer patients;breath biomarkers;PTR-MS;VOCs;non-invasive analysis
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发布时间： - 摘要：A novel DNA sensor was designed for the determination of breast cancer genes based on three electrochemical probes,the negative electrochemical probe ［Fe(CN)6］3-/4-,methylene blue and the positive electrochemical probe［Ru(NH3)6］3+.The breast cancer genes DNA sensor was fabricated by immobilizing a breast cancer gene ssDNA onto the surface of gold nanoparticles-multi-walled carbon nanotubes(MWCNT)-Nafion modified gold electrode through adsorption,and characterized by cyclic voltammetry,differential pulse voltammetry and electrochemical impedance method.Under the optimized conditions,in 5 mmol/L K3［Fe(CN)6］ -5 mmol/L K4［Fe(CN)6］(pH=7.4) solution,the electrochemical current response of the sensor was linear with the logarithm of the breast cancer gene concentration in range of 0.1-500.0 nmol/L,with a detection limit(S/N=3) of 0.03 nmol/L.While using methylene blue as the electrochemical probe,the electrochemical current response was linear with concentration of breast cancer gene in range of 1.0-500.0 nmol/L,and the detection limit was 0.3 nmol/L.Based on the different binding ability of ［Ru(NH3)6］3+with ssDNA and dsDNA,the current response of the sensor using ［Ru(NH3)6］3+ as the probe was still linear with concentration of breast cancer gene in the range of 1.0-500.0 nmol/L.The detection limit was 0.3 nmol/L.Among three kinds of electrochemical probes,［Fe(CN)6］3-/4- probe had the lowest detection limit and the widest linear range for the detection of breast cancer gene.关键词：electrochemical biosensor;breast cancer gene;electrochemical probe;multi-walled carbon nanotubes;gold nanoparticles;Nafion
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发布时间： - 摘要：A method was established for the rapid detection of 15 kinds of antibiotics(quinolones,chloramphenicol,tetracycline and sulfonamides) in river water near fish farms by ultra performance liquid chromatography-tandem triple quadrupole mass spectrometry(UPLC-MS/MS) with solid-phase extraction.After filtration,a 500 mL of water sample was adjusted to pH 4.0 with hydrochloric acid,then added 0.5 g ethylenediaminetetraacetic acid disodium(Na2EDTA) to removal the interference of variousmetal ions,and finally enriched with an HLB solid-phase extraction column.The sample was detected by ultra performance liquid chromatography couple with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF MS),and screened for the antibiotics with antibiotic library.The corfirmation and quantitation of antibiotics in the sample were performed by UPLC-MS/MS in multi-period multi-reaction monitoring ion mode(MRM) with external standard method.The spiked recoveries for 15 antibiotics in blank matrix were in the range of 61.0%-98.4% with the relative standard deviations(n=3) of 4.6%-14.0%.The calibration curves of 15 antibiotics showed good linearity with the correlation coefficients not less than 0.990.The method detection limits(MDLs) ranged from 0.01 ng/L to 0.3 ng/L.With high sensitivity and good repeatability,this method could be applied in the detection of antibiotics in fish pond water in Beijing.关键词：ultra performance liquid chromatography-mass spectrometry;solid-phase extraction;antibiotics;fish pond water;fast screening
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发布时间： - 摘要：A liquid chromatography with fluorescence detection(LC/FLD) combined with dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the simultaneous analysis of six hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs) in human urine.The important parameters affecting the extraction efficiency,including the type and volume of extraction and dispersive solvents,urine pH value,salt concentration and extraction time were optimized.Under optimized conditions,the urine sample was adjusted to pH 5.0,then enzymatically hydrolyzed and added 20% NaCl to adjust the ion strength.400 μL dispersive solvent acetone and 40 μL extraction solvent 1-undecanol were rapidly injected into the urine sample.After vortexed and centrifuged at 3 000 r/min for 5 min,the urine was kept in a -20 ℃ refrigerator for ten min untill the floating organic droplets were solidified and could be easily collected with a spoon into a clean cell bottle.The collected 1-undecanol was injected into LC for analysis after it melted.The results showed that there existed a linear range of 2.5-150.0 μg/L for six targeted OH-PAHs in urine with their correlation coefficients(r2) of 0.999 1-0.999 8.The extraction recoveries were in the range of 70.4%-129% with RSDs of 1.7% -14.8%.The limits of detection and quantification were in the ranges of 0.5-1.0 μg/L and 1.5-3.0 μg/L,respectively.With the advantages of simplicity and rapidness,the developed method could satisfy the requirments for large sample analysis on actual human urine.关键词：dispersive liquid-liquid microextraction based on the solidification of floating organic droplet;liquid chromatography(LC);hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs);human urine
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发布时间： - 摘要：Qualitative and quantitative determinations on main components in health food were performed by the nuclear magnetic resonance(NMR) techniques such as diffusion-ordered NMR spectroscopy(2D-DOSY) and pulse length based concentration determination(PULCON).In this experiment，Bruker Avance Ⅲ 600 MHz was applied,with acetone-d6 as solvent.2D-DOSY spectra demonstrated that the sample contained three compounds.1H-1H correlation spectroscopy(COSY) and total correlation(TOCSY),1H-13C heteronuclear single quantum coherence spectroscopy(HSQC) and 1H-13C heteronuclear multiple bond correlation(HMBC) were used to assign the chemical shifts of the compounds,which were finally determined to be diethyl phthalate,melatonin and omeprazole.Finally,a quantitative PULCON method was developed to determine the contents of by-products,and the contents of the three compounds were 16.65,5.38,46.35 mg/g,respectively.The results indicated that the NMR spectroscopy,compared with HPLC method,is a more direct and rapid method for analysis on the structures and contents of non-target compounds in health food with no need of standard reference and separation.关键词：NMR;diffusion-ordered NMR spectroscopy(DOSY);pulse length based concentration determination (PULCON);health food;non-target component
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发布时间： - 摘要：A method based on ultra performance liquid chromatography-tandem mass spectrometry with chiral stationary phase was developed for the simultaneous analysis of five chiral pesticide residues(paclobutrazo,myclobutanil,metalaxyl,triazolone and famoxadone) in leafy vegetables,including Chinese flowering cabbage and leaf lettuce.The sample was extracted with acetonitrile,then purified with primary secondary amine and graphitized carbon black.The upper clear liquid was filtered after centrifugation.After separated with a CHIRRALCEL OD-RH chiral column,the extract was detected using UPLC-MS/MS.Results indicated that the calibration curves of the five chiral pesticides showed good linear relationships in the concentration range of 0.005-1.0 mg·L-1.The recoveries at three spiked levels of 0.01,0.1,0.5 mg·kg-1 were in the range of 68.8%-104% with relative standard deviations of 1.0%-13.7%. This method is rapid,convenient and reliable,and could meet the requirements for residue analysis,and could provide a technical support for the investigation on five chiral pesticides residues in vegetables and their digestion regularity.关键词：chiral resolution;ultra high liquid chromatography-tandem mass spectrometry;enantiomers;vegetables
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发布时间： - 摘要：A method was established for the high-throughput screening of 13 digestive drugs adulterated in biochemical drugs,Chinese patent medicines and dietary supplements by high-performance liquid chromatography-Orbitrap high resolution mass spectrometry(UHPLC-HRMS).Samples were extracted with methanol-water(50∶50，by volume),chromatographically separated on a Hypersil Gold C18(2.1 mm×100 mm,3 μm) column with acetonitrile-0.1% formic acid as mobile phase by gradient elution.The analysis time for a single injection was merely 10 min.MS detection was performed in positive ion Full MS/dd-MS2 scan mode.Comparing the chromatographic retention time,high resolution primary and secondary mass spectra of the sample with those of the reference substance,it could be judged whether the digestive drug was adulterated into the test samples or not,and the positive samples were quantified.The linear ranges for these 13 digestive drugs were all 8.0-800 μg/L with their correlation coefficients(r) no less than 0.998 5.The recoveries were over the range of 94.6%-106.2% with relative standard deviations of 1.2%-2.9%.With the advantages of rapidness,simplicity,high-throughput,good selectivity and high sensitivity,this method was used for the high-throughput screening and determination on 13 kinds of digestive chemicals adulterated in biochemical drugs,Chinese patent medicines and dietary supplements.Five batches of positive samples were found in 38 batches of Chinese patent medicines,and three batches of positive samples were found in 43 batches of dietary supplements.关键词：digestive drug;illegally adulteration;Orbitrap high resolution mass spectrometry;determination;high-throughput screening
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发布时间： - 摘要：An ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the determination of 13 anti-diabetic ingredients illegally added in formulated foods on special medical purposes.Samples were extracted with 90% acetonitrile containing 1% formic acid,and then purified with an Oasis PRiME HLB column.The extraction was on a Waters ACQUITY UPLC BEH C18(150 mm×2.1 mm，1.7 μm) column with methanol-5 mmol/L ammonium acetate solution containing 0.1% formic acid as mobile phases by gradient elution.The analysis on the analyte was performed by UPLC-MS/MS under positive electrospray ionization in multiple reaction monitoring(MRM) mode,Effects affecting the recoveries such as dosage of extractant,formic acid and acetonitrile in cleaning-up agent were investigated.The main influence factors and analytical conditions were modified.Results showed that there were good linear relationships for 13 ingredients in the concentration range of 2-100 μg/L with their correlation coefficients(r2) no less than 0.995 1.The recoveries at three concentration levels ranged from 80.9% to 102.8% with LOQs of 0.3-1.0 μg/kg.With simple pretreatment,high recovery and good reproducibility,the developed method was suitable for the determination of 13 anti-diabetic ingredients illegally added in formulated foods on special medical purposes.关键词：ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);dispersive solid phase extraction;foods for special medical purpose;anti-diabetic
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发布时间： - 摘要：A method for the determination of scopoletin in Tengluoning capsule by three-dimensional fluorescence combined with unfolded partial least squares coupled to residual bilinearization(U-PLS/RBL) was developed.Experiments showed that scopoletin has a strong fluorescent signal.The optimum pH of the system was 9.0,the maximum excitation wavelength of scopoletin was 375 nm,and the maximum emission wavelength was 460 nm.Excitation-emission matrices(EEM) of Tengluoning capsule samples were obtained,recording emission between 400 nm and 550 nm,exciting between 310 nm and 420 nm,for the analysis of scopoletin.An effective second-order calibration method,U-PLS/RBL(unfolded partial least-squares coupled to residual bilinearization) was used to analyze the three-dimensional fluorescent data array,and the content of scopoletin was successfully determined.The predicted U-PLS/RBL concentrations were satisfactory compared with those obtained by high performance liquid chromatography with fluorescence detection.The average recovery by U-PLS/RBL was 100.4%，which indicated that the proposed method was reliable.Compared to chromatographic method,the fluorescent method has the advantages of low operating cost and pro-environment.关键词：U-PLS/RBL;scopoletin;Tengluoning capsule;HPLC;three-dimensional fluorescence
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发布时间： - 摘要：In this work,an Ag nanoparticles-graphene composite nanomaterial(AgNPs-GN) was prepared by redox reaction.And an Ag nanoparticles-graphene modified glass carbon electrode(AgNPs-GN/GCE) was fabricated by immobilizing AgNPs-GN on the surface of the glass carbon electrode.The electrochemical behaviors of paracetamol on AgNPs-GN/GCE and GN/GCE were investigated in B-R buffer solution(pH 4.78) by cyclic voltammetry and square wave voltammetry.Both modified electrodes had electrocatalytic activity for the redox of paracetamol,and the AgNPs-GN/GCE possessed a more excellent electrocatalytic effect.Under the optimal conditions,the reduction peak current of paracetamol was proportional to its concentration in the range of 1.0×10-7-5.0×10-4 mol/L with the detection limit of 3.0×10-8 mol/L.A new method for the determination of paracetamol in tablets was established.The modified electrode showed an excellent stability and a good reproducibility.关键词：paracetamol;Ag nanoparticles;graphene(GN);modified electrode;electrocatalysis
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发布时间： - 摘要：The enzyme kinetic constants(Ki,Ka,K2) and half inhibitory concentration(IC50) were determined to reveal the kinetic characteristics of wheat bran esterase with the index of enzyme activity inhibition rate.Results showed that,the sensitivity order of wheat bran esterase to three organophosphorus pesticides was as follows: dichlorvos＞methyl parathion＞dimethoate,and that to carbamate pesticides was: isoprocarb>carbaryl>carbosulfan.In addition,the corresponding IC50 values for the six pesticides were 0.176,1.754,2.583,0.489,0.799,2.035 mg/L,respectively.The conclusion that the inhibitory effects of pesticides on wheat bran esterase were selective in different degrees was obtained by comparing the kinetic constants(Ki，Ka，K2) of wheat bran esterase and IC50 values of the six pesticides.And the main reason for the difference of the sensitivity to pesticides was the affinity of wheat bran esterase and pesticides.Actually,lettuce,green beans and grapes were detected to contain pesticides by using this method,and the pesticide residues in grape were confirmed to be dimethoate.The method could provide a theoretical basis for the application of wheat bran esterase in pesticide detection.关键词：wheat bran esterase;enzyme dynamics;pesticide residue;sensitivity;organophosphorus;carbamate
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发布时间： - 摘要：A novel molecular imprinted polymer(MIP) sensor was successfully prepared for selective direct detection of nitrofurantoin in water and feed samples.To obtain the fluorescent sensor,carbon quantum dots(CDs) were synthesized by using citric acid as carbon source,modified with silane agent to introduce polymerizable bonds on the CDs surface,then a nitrofurantoin molecularly imprinted polymer(MIP) nanofilm was attached on the modified CDs surface.The structure and morphology of CDs and MIP-CDs were characterized by fourier transform infrared(FTIR) spectroscopy and scanning electron microscopy(SEM).A series of adsorption experiments were performed to investigate the absorption capacity of MIP-CDs.The results showed that the relationship between fluorescence quenching and nitrofurantoin concentration followed the Stern-Volmer equation with a good linear response in the range of 0-10 mg/L,and the detection limit for nitrofurantoin was 2 μg/L.In addition,the MIP-CDs were employed to detect the nitrofurantoin in water and feed samples with recoveries of 78.0%-95.2% and RSDs not more than 6.4%(n=3).The developed method was simple,rapid and selective,and was suitable for the analysis of trace nitrofurantoin in water and feed samples.关键词：carbon quantum dots;molecular imprinted polymer;fluorescent sensor;nitrofurantoin
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发布时间： - 摘要：The chemical state variation of Cu element and its influencing factors on Cu modified vanadium-based de-NOx catalyst were investigated by X-ray photoelectron spectrometry(XPS).The results showed that Cu element in catalyst existed in the forms of CuO and Cu2O,and CuO could be reduced under X-ray irradiation.However,the initially observed Cu2O was mainly derived from the prepared samples other than generated by X-ray.The influencing factors for the reduction from CuO to Cu2O included the irradiation time and power of X-ray,copper load and sample preparation methods,etc.The results indicated that the reduction percentage for CuO increased gradually with the increase of irradiation time or power of X-ray.In general,the reduction percentage for CuO decreased with the increase of Cu load.The reduction percentage for CuO keeped at the level about 1.2%when the Cu load reached to 3%.The existence of the active component vanadium increased the reduction activity of CuO,while the addition of oxalic acid reduced the reduction activity.This study provided an important reference for the characterization and analysis of Cu modified vanadium denitrification catalyst,and also gave some suggestions for parameter settings and analysis method for other similar X-ray sensitive samples.关键词：XPS;Cu modified vanadium-based de-NOx catalyst;CuO;Cu2O;reduction
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发布时间： - 摘要：A non-targeted metabolomics method for investigation on metabolite profiling of rice seed was developed based on gas chromatography-mass spectrometry.The extraction efficiencies of three extraction methods and four extraction solvents were investigated.Results showed that vortex and methanol-water(80∶20,by volume) were highly efficient for metabolites extraction from rice.With good stability and linearity,This method was applied in investigation on metabolite profiling of rice,including Nongda,Daohuaxiang and Zhuangyuan.It was found that they have different metabolic phenotype.Compared with Nongda,Daohuaxiang contained more contents of hexadecanoic acid,oleic acid,linoleic acid,octadecanoic acid,glucose,galactose,mannitol,asparagine and citric acid,and Zhuangyuan also had more lactic acid.Nevertheless,Nongda had more succinic acid and fructose than daohuaxiang,and more threonine than Zhuangyuan.And the contents of lactic acid,succinic acid,octadecanoic acid and fructose in Daohuaxiang were lower than those in Zhuangyuan.The developed method could be used for investigation on the metabolic phenotype of rice with different types,genotypes or habitats.It was expected to provide useful information for improving rice production and quality.关键词：rice;non-targeted metabolomics;gas chromatography coupled with mass spectrometry;metabolic phenotype
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发布时间： - 摘要：A method with high sensitivity,high throughout and low sample consumption was developed for the analysis of trace elements in human serum by inductively coupled plasma mass spectrometry(ICP-MS).As the matrix was complicated,the sample was diluted with a mixture of four butyl ammonium hydroxide,Triton and EDTA.The internal standard correlation and collision/reaction cell were used to eliminate the matrix effects and polyatomic ion inteferences.Ten trace elements of Al,Cu,Fe,Zn,Ga,As,Cd,Hg,Tl and Pb were simultaneously determined after tuning up the instrument and optimizing the collision/reacion cell parameters,and the spiked recovery for each element ranged from 87.2% to 111.2%.This method was used in the analysis of human serum standard(ClinChek-Control，Level Ⅰ and Level Ⅱ).The determined values were in good agreement with the certified values.The reference values for different age groups and sex groups were listed based on the determination of 127 serum samples from healthy adults.关键词：human serum;inductively coupled plasma mass spectrometry(ICP-MS);trace elements;direct dilution
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发布时间： - 摘要：A novel method for the simultaneous determination of dissolved phenanthrene(Phe) and its intermediate metabolite 1-hydroxy-2-naphthoic acid(1H2NA) in aqueous solution was established by using derivative synchronous fluorescence spectroscopy.The linear dynamic ranges for the determination of Phe and 1H2NA were 4.0-1.0×103 μg/L and 4.0-1.2×103 μg/L,with the detection limits of 0.08 μg/L and 0.07 μg/L,and the spiked recoveries of 96.5%-105.3%and 99.2%-106.5%,respectively.And the relatively standard deviations were less than 1.0%.The established method was successfully applied in the determination of Phe and 1H2NA during biodegradation of dissolved Phe in lab,which showed that it has a potential in in situ determination of Phe and 1H2NA.关键词：phenanthrene;1-hydroxy-2-naphthoic acid;metabolites;derivative synchronous fluorescence spectroscopy
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发布时间： - 摘要：A simple,rapid and sensitive fluorescence analytical method was developed for the determination of thiamazole based on the quenching of gold nanoparticles in different aggregation states to rhodamine B.The mechanism of the detection system was discussed,and the effects of experimental factors such as pH value,reaction time and concentrations of the involved reagents were investigated.Under the optimum conditions,calibration curve was linear in the range of 4.38×10-8 -0.876×10-5 mol/L with the detection limit of 3.30×10-8 mol/L.The method was successfully applied in the determination of thiamazole in thiamazole tablets.关键词：gold nanoparticles;rhodamine B;fluorescence quenching;thiamazole
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发布时间： - 摘要：Molecularly imprinted polymers(MIPs) for malathion were synthesized by suspension polymerization,using azobisisobutyronitrile as the thermal polymerization initiator.The optimum conditions were as follows:the ratio of template molecule(malathion),functional monomer(methacrylic acid) and cross-linker(ethylene dimethacrylate):1∶8∶40,the reaction temperature:60 ℃,the amount of thermal polymerization initiator:1.0%.The maximum adsorption of MIPs was 4.62 μg/mg under the optimum conditions,while that of molecularly non-imprinted polymers was 2.21 μg/mg.The absorption amounts of MIPs for ethoprophos,phorate,terbufos,dimethoate,malathion,and fenamiphos were 3.87,3.75,3.57,4.00,4.44,3.61 μg/mg,respectively,while those of the non-imprinted polymers were 1.42,1.37,1.30,1.43,1.12,1.23 μg/mg,respectively.关键词：malathion;molecularly imprinted polymers;suspension polymerization;adsorption performance
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发布时间： - 摘要：Chemical fingerprint technology is one of the most important parts of quality evaluation system for Chinese ethnomedinins,which development has close relationships with quality control,safety and effectiveness of ethnomedinins.In the present study,many analysis technologies such as TCL,HPLC,GC,IR,UV,Raman spectra,XRD and NMR have been widely used in the quality control on ethnomedinins.In this review,the current status and progress in the applications of chemical fingerprint in the studies of species identification,productions region decimation and quality evaluation of ethnomedinins made by both domestic and foreign scholars have been summarized.This review may provide references for the resources evaluation,quality control and innovation and development of Chinese ethnomedinins.关键词：ethnomedinine;chemical fingerprint;quality control;identification of materia medica;research progress
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发布时间： - 摘要：A review on chemical amplification methods and techniques is presented in this paper.Such chemical amplification approaches are introduced by overview of enrichment,buffer amplification,non-aqueous milieu and sequential reaction.Enrichment could obtain higher reagent concentration by pre-concentration.Buffer amplification is achieved by additional enthalpy of buffer proton-producing reactions.Non-aqueous milieu is achieved by temperature rise caused by decrease of specific heat.Sequential reaction has notable increase of total enthalpy contributed by net enthalpy change of each reaction in the cycle.More broadly,recent literatures to address these issues are also introduced.Their applications could help to enhance the test performance of calorimetric system like calorimetric biosensor achieved by improving effective enthalpy change.Taking inherent advantages of robust technique and crude samples detection,calorimetry combined with chemical amplifications is easy to operate,and must have a good propect in trace analysis field.关键词：chemical amplification;calorimetry;enrichment;protonation reaction;sequential reaction;review
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