最新刊期
卷 37 ， 期 2 ， 2018
- 摘要：Mass spectrometry is accepted as a universal tool with high sensitivity,specificity and speed among various modern analytical technologies,and has been widely applied as a high-throughput and rapid detection technology in fields of food inspection,environmental monitoring,drug screening,clinical medicine,etc.In this paper,recent advances in low-resolution mass spectrometry(LRMS),high-resolution mass spectrometry(HRMS) and ambient ionization mass spectrometry(AIMS) in high-throughput and rapid detection,particularly toward small molecule compounds have been reviewed,and the trends and prospective for the development of mass spectrometry have been discussed,which may provide a theoretical support and a technical guidance for the researchers engaged in relevant fields.关键词：mass spectrometry(MS);low-resolution mass spectrometry(LRMS);high-resolution mass spectrometry(HRMS);ambient ionization mass spectrometry(AIMS);high-throughput rapid detection technology;review
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发布时间： - 摘要：Time-of-flight mass spectrometry(TOF-MS) is a kind of mass spectrometric technique with high scan speed,wide scan range,high sensitivity and high mass resolution abilities.Compared with the conventional ion trap and quadruple mass spectrometry,TOF-MS has higher qualitative and throughput screening abilities.The applications of qualitation and quantitation on pesticide residues in the field of quality and safety on agricultural products have become more and more important.With the continued improvement and development of TOF-MS technique,it has been considered a powerful research tool for researchers.In this paper,the literatures on TOF-MS applications in analysis of pesticide residues in fruit,vegetable and tea,published at home and abroad since 2010，are reviewed in three aspects where it is coupled with gas chromatography,liquid chromatography and convergence chromatography.The development prospect of this TOF-MS technique in pesticide residue analysis of fruits,vegetables and tea is also prospected.关键词：time-of-flight mass spectrometry;fruit;vegetabl;tea;pesticide residueanalysis;review
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发布时间： - 摘要：A method for the simultaneous screening and determination of 248 pesticide residues in apples and lettuces was developed by liquid chromatography coupled with high resolution quadrupole time-of-flight mass spectrometry(LC-Q TOF/MS).The samples were extracted with 10 mL acetonitrile and 5 mL 0.1%(by volume) acetic acid,cleaned up by a modified QuEChERS method.Confirmation was achieved by electro-spray ionization(ESI) in positive mode using SWATH MS acquisition,and quantification was carried out by external standard method.Two databases of accurate mass and fragment ions were created.The standard matrix-matched calibration curves of 248 target compounds were linear in the range of 0.010-0.200 mg/L,with the correlation coefficients(r) larger than 0.99.The limits of quantification for 248 target compounds all were 0.010 mg/kg.The mean recoveries for the target compounds at three spiked levels of 0.010,0.050，0.100 mg/kg ranged from 25.2% to 128%,32.4% to 132%and 28.9% to 133%,respectively with relative standard deviations of 0.98%-21.2%(n=6).With the advantages of simplicity,timesaving,high sensitivity and good stability,the method was applicable for the simultaneous screening and determination of 248 pesticide residues in apples and lettuces,and could significantly reduce the test cost.关键词：LC-Q TOF/MS;high resolution mass spectrometry;pesticide residues;screening;apple;lettuces
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发布时间： - 摘要：An analytical method was developed for the rapid screening and quantitative detection of fifteen phthalates(PAEs) plasticizers in plastic toys by ultra performance liquid chromatography-hybrid quadrupole time of flight mass spectrometry(UPLC-Q TOF MS).Plastic toy samples of different matrixes were extracted by a solvent dissolution-ultrasound extraction-precipitation seperation,cleaned up with a graphite carbon solid phase extraction column and concentrated by rotary evaporation and nitrogen blowing,then separated on a C18 column(2.1 mm×50 mm,1.7 μm) by gradient elution,and detected in positive electrospray ionization(ESI+) and information dependent acquisition(IDA) MS/MS mode.The qualitative analyses for fifteen PAEs were performed by the synergic combination of the accurate m/z of TOF MS,isotopic distribution,retention time and library search results.The quantitative analyses were performed using the peak area of the extracted m/z of TOF MS.Experimental results demonstrated that a favorable mass accuracy less than 3 ppm was obtained for fifteen PAEs,and good linearities(r2>0.996) were observed in the respective concentration ranges.The limits of detection(LODs) and limits of quantitation(LOQs) were in the ranges of 4.66-11.69 μg/kg and 13.04-30.71 μg/kg,with intra-day and inter-day(n=7) precision less than 3.8% and 6.7%,respectively.The recoveries at three spiked levels ranged from 80.5% to 108.3%,with relative standard deviations(RSDs,n=6) of 0.4%-12.3%.The present method was practically used to detect butyl benzyl phthalate in a plastic toy.This method was proved to be accurate,efficient and specific,and could be applied for the inspection of commercial plastic toys.关键词：phthalates;plasticizers;solid phase extraction;ultra performance liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF MS);plastic toys;screening
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发布时间： - 摘要：A method for the rapid and high-throughput identification of fish species using thin-film biosensor chips was developed.Based on the parvalbumin gene,a set of universal primers and specific probes were designed for eight fish species including Turbot,Silvery pomfret,Tuna,Obscura puffer,Indigo hamlet,Hairtail,Large yellow croaker and Miniatus grouper.The assay,with the characteristic of high specificity and throughput,could produce signals visualized by the unaided eye without any specific instruments.And the detection limit reached to 0.1 ng/μL.This method provided an important technical means for identifying eight fish species,which could be utilized in rapid screening for fish adulteration.关键词：thin-film biosensor chip;fish;identification;high-throughput
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发布时间： - 摘要：A new method and mass spectral database for screening pesticide residues in fruits and vegetables by liquid chromatography-high resolution benchtop/orbitrap mass spectrometry（HRMS） with on-line cleanup were developed.The samples were extracted with acetonitrile containing 0.1% acetic acid,then purified and collected with a Cyclone-P column.The analytes were separated on a C18 column with acetonitrile-0.5 mmol/L ammonium acetate containing 0.1% acetic acid as mobile phase by gradient elution.212 pesticides residues were analyzed by high-resolution mass spectrometry Q-Orbitrap in full scan/ddMS2 mode under switching positive and negative mode.The calibration curves were linear in the range of 0.5-50 μg/L with correlation coefficients more than 0.998.The limits of quantitation（LOQs） reached to 5 μg/kg.The average recoveries of the analytes at a spiked level of 10 μg/kg were in the range of 58.3%-129.4%,with their relative standard deviations of 2.8%-16.0%.The method could be used for the rapid screening of 212 compounds in fruits and vegetables by means of accurate mass of quasi-molecular ion,retention time,isotope ratio and qualitative fragments without any reference standards.关键词：on-line cleanup;liquid chromatography;orbitrap high-resolution mass spectrometry;pesticide residues;high-throughput;fruits and vegetables
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发布时间： - 摘要：A molecularly imprinted electrochemical sensor based on gold electrode decorated with reduced graphene oxide(rGO) incorporated gold nanoparticles(AuNPs) was developed for the selective determination of lomefloxacin hydrochloride(LMX).The AuNPs-rGO nanocomposites were modified onto the gold electrode through the electrochemical reduction of graphene oxide and HAuCl4.The imprinted poly-o-phenylenediamine(o-PD) and m-dihydroxybenzene(m-DB) membrane,which was embedded in AuNPs-rGO surface,functioned as a selective recognition element for LMX.The electrochemical behaviors of the imprinted sensor were characterized by cyclic voltammetry(CV) and differential pulse voltammetry(DPV) using K3［Fe(CN)6］ as the redox probe.The results showed that the imprinted sensor displayed a high selectivity for LMX,and the introduced AuNPs-rGO composites significantly enhanced the electronic transmission and sensitivity.Under the optimal conditions,the DPV peak currents of the redox probe were linear with LMX concentrations in the range of 0.01-1.0 μmol/L,with a detection limit of 3.0 nmol/L(S/N=3).The method was applied in the determination of LMX in Xijiang water and milk samples with a satisfactory precision(RSD≤6.2%) and acceptable recoveries(88.0%-102%).关键词：molecular imprinted sensor;lomefloxacin hydrochloride;AuNPs;reduced graphene oxide;electropolymerization;water;milk
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发布时间： - 摘要：Nitrogen-doped carbon quantum dots(CQDs) with thermal sensitivity were rapidly prepared using microwave-assisted method with oxalic acid and urea as carbon source,and ultrapure water as solvent.The morphology,structure,fluorescence properties of the as-prepared CQDs,and influencing factors of fluorescence intensity,as well as cytotoxicity of CQDs with MTT assay were discussed in the article.Finally,the CQDs applied in CT26.WT cell imaging.The results showed that the as-prepared CQDs,possessing a quasispherical morphology with an average diameter of approximately 3.8 nm,exhibited a good temperature-sensitive photoluminescence property.The temperature-dependent fluorescence was from 10 ℃ to 80 ℃.With the increase of temperature,the fluorescence intensity of CQDs decreased,while the relative fluorescence intensity(I/I0) of CQDs decreased by 25%with the increase of temperature from 10 ℃ to 80 ℃,which could recover to the initial value with the decrease of temperature.There was an accurate linear relationship between fluorescence intensity and temperature of CQDs,which demonstrated one of its potential applications in the field of temperature--dependent photoluminescence sensing.The nitrogen doping could effectively improve the fluorescence quantum yield(QY) of CQDs.When the mass ratio of oxalic acid and urea was 3∶1,the fluorescence quantum yield reached the maximum value of 9.5%.FTIR analysis showed that the CQDs surfaces were rich in hydroxyl and carboxyl groups,which were helpful for water-solubility and cell imaging application.The as-prepared CQDs exhibited an excitation-dependent photoluminescence performance,excellent salt tolerance ability and good stability.Moreover,the luminescent CQDs could not only be efficiently taken up by CT26.WT cells,but also exhibited a low cytotoxicity and a favorable biocompatibility.MTT assay results showed that cell viability remained 85%for CT26.WT in the presence of CQDs in the concentration of 1 000 μg·mL-1.All these excellent properties make the thermo-sensitive CQDs become a promising candidate in the applications of cell research.关键词：carbon quantum dots;preparation;microwave method;temperature-dependent fluorescence;cell imaging
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发布时间： - 摘要：A β-cyclodextrin functionalized graphene modified glassy carbon electrode(β-CD-GR/GCE) was prepared by drop-coating method.The electrochemical behaviors of o-nitrophenol(o-NP) and p-nitrophenol(p-NP) on the modified electrode were investigated by cyclic voltammetry and second-order derivative linear sweep voltammetry.The β-CD-GR/GCE showed an excellent electrocatalytical effect on the reduction of p-NP and o-NP.Besides,high resolution capacity to p-NP and o-NP was obtained.Under the optimized conditions,second-order derivative linear sweep voltammetry was utilized for the determination of p-NP and o-NP.There were good linearities for o-NP and p-NP in the concentration ranges of 0.2-10 μmol/L and 0.06-10 μmol/L with detection limits(S/N=3) of 0.08 μmol/L and 0.02 μmol/L,respectively.The proposed method could be applied in the simultaneous determination of o-NP and p-NP in environmental water samples with rapidness and accuracy.关键词：β-cyclodextrin functionalized graphene;modified electrode;o-nitrophenol;p-nitrophenol;electrochemical behavior;determination
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发布时间： - 摘要：An analytical method based on ultra performance liquid chromatography-quadrupole linear ion trap mass spectrometry(UPLC-QTRAP-MS/MS) was established for the simultaneous determination of galanthamine(Gal),lycoramine(Lycm) and lycorine(Lyc) in Lycoris.After ultrasonic-assisted extraction and centrifugation,the sample was seperated on a Waters ACQUITY UPLC BEH C18 column(150 mm×2.1 mm，1.7 μm) by gradient elution with acetonitrile-water(0.1% formic acid) as mobile phase at a flow rate of 0.2 mL/min.The three target compounds were analyzed in the positive ion multiple reaction monitoring(MRM) mode.Results showed that good linearities for the analytes were obtained in the concentration range of 0.5-500 μg/L with their correlation coefficients of 0.999 9-1.000 0 within 6 mins,and the retention times for Gal,Lycm and Lyc were 2.86 min,2.31 min and 1.95 min,respectively.The average recoveries were between 97.2%-98.6% with relative standard deviations of 0.8%-4.3%. The contents of Gal,Lycm and Lyc in 12 Lycoris species were determined to be 21.98-496.77 μg/g,0.17-467.21 μg/g and 9.34-4 510.18 μg/g by dry weight,respectively.Large differences were observed among species.This method was sensitive and accurate,and could provide a reliable and effective approach for the accumulation detection and metabolic regulation of alkaloids in Lycoris．关键词：Lycoris;UPLC-QTRAP-MS/MS;galanthamine;lycoramine;lycorine
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发布时间： - 摘要：The main impurities in octylferrocene were its three isomers including(2-octyl)-ferrocene,(3-octyl)-ferrocene and(4-octyl)-ferrocene,which derived from the preparation of industrial product octylferrocene by separation.It is difficult to assess the purity of the isomers with high precision as the related reference materials for metal organic compounds are still in shortage at home and abroad.In this paper,gas chromatography was firstly employed to investigate the homogeneity and stability of the isomers prepared in laboratory,then the kinds of impurities in them were determined,and the mass balance approach was utilized to estimate the purity of the candidates.The purity assessment on organic impurities was mainly studied,and the uncertainty for the results were evaluated in the end.This may lay a foundation for the application of related substances in high-tech field.关键词：(2-octyl)-ferrocene;(3-octyl)-ferrocene;(4-octyl)-ferrocene;isomers;purity assessment;gas chromatography
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发布时间： - 摘要：A method was developed for the determination of 19 quinolone antibacterials residues in aquatic products by high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with PRiME HLB purification technique.In this research,the parameters such as purification,concentration,liquid phase separation and mass spectrometry were optimized.The samples were extracted with 80%acetonitrile-water mixed solution,purified with a PRiME HLB column,and quantified by UPLC-MS/MS in MRM mode after gradient elution on an ACQUITY BEH C18 column(1.7 μm,2.1 mm×100 mm) with methanol and 5 mmol/L ammonium acetate solution containing 0.1%formic acid as mobile phase.The results showed that there existed good linear relationships for the components in their respective concentration ranges.The average recoveries were in the range of 72.1%-119.9%with the relative standard deviations of 2.4%-15.6%，the detection limits of 0.5 μg/kg and the quantitation limits of 1.5 μg/kg.With the advantages of good accuracy,simplicity and high sensitivity,this method is suitable for the determination of quinolone antibacterials in aquatic products,and it provides a new way for the determination of quinolone antibacterials residues in aquatic products.关键词：aquatic products;quinolone antibacterials;PRiME HLB;high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)
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发布时间： - 摘要：A rapid,specific and simple method was established for the quantitative determination of active components in N-catalyst by proton nuclear magnetic resonance spectroscopy.1H NMR spectra were obtained using CD3OD as solvent and hydroquinone as the internal standard with suitable acquisition time and delay time.By quantifying with the optimized experiment parameters,the average results of the active components,TBP,PA-DCP-TiCl3,DCP-TiCl3 and DNBP were 0.21%,0.58%,1.21%and 5.82%with their RSDs of 0.75%，0.89%，0.41%and 0.35%,respectively,which were in accordance with those measured by HPLC.This method was validated for the quantitative determination of active components in N-catalyst with no need of the standard reference compound.In the study of the chemical structures of the active components in N-catalyst by NMR,their contents could also be determined simultaneously.It provided a new way for the quantitative determination of the electron donor in preparation of N-catalyst.关键词：nuclear magnetic resonance;internal standard method;N-catalyst;electron donor
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发布时间： - 摘要：A method for the determination of nineteen organic solvent residues in dyeing and finishing auxiliaries by gas chromatography-mass spectrometry（GC-MS） was developed.Sample was acidified with formic acid,and then esterified with ethanol.After extraction with hexane,the qualitative and quantitative analyses were performed by the optimized GC-MS.The limits of detection for nineteen organic solvent residues were between 0.03 mg/kg and 0.1 mg/kg.The calibration curves for nineteen organic solvent residues showed good linearity in the concentration range of 0.5-50 mg/L with their correlation coefficients not less than 0.999.The average recoveries of the analytes in different negative samples at different spiked levels ranged from 94.3% to 101.3%,with relative standard deviations（RSDs） less than 8.7%.The established method was reliable,accurate and sensitive,and was suitable for the determination of nineteen organic solvent residues in dyeing and finishing auxiliaries.关键词：dyeing and finishing auxiliaries;organic solvent residues;gas chromatography-mass spectrometry
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发布时间： - 摘要：An analytical method for the simultaneous determination of 15 kinds of organic solvents residues in food additives based on headspace-gas chromatography was established.The residual organic solvents in different food additives were extracted with N,N-dimethylformamide using centrifuge tubes.To achieve the optimum conditions for the analysis,several parameters including the extraction solvents,extraction method,equilibrium temperature and equilibrium time were optimized.The results showed that there existed good linearities for the solvent residues in the respective concentration ranges with their correlation coefficients no less than 0.999 8.The limits of quantification for the target compounds were 10.0 mg/kg except that those for pyridine and chloroform were 20.0 mg/kg.The recoveries for 15 organic solvents residues were in the range of 90.6%-109.1%with relative standard deviations(RSDs) of 0.1%-7.2%.This method is sensitive and accurate,and is suitable for the determination of organic solvents residues in food additives.关键词：headspace-gas chromatography;food additives;organic solvents residues
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发布时间： - 摘要：A novel and label free electrochemical immunosensor for salbutamol(SAL) detection was developed with alizarin (AR) as a redox probe,and titanium dioxide hybridized acetylene black and chitosan composites (TiO2-AB-CS) as a signal amplification platform.Au NPs were electro deposited on the modified electrode surface to immobilize the SAL antibody(anti SAL),which could further enhance the current response.Scanning electron microscope(SEM) was used to characterize the materials.Cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) were used to characterize the construction process of modified electrode and the electrochemical properties of the immunosensor.Differential pulse voltammetry(DPV) was used to detect the peak current of alizarin on the surface of modified electrode,the peak current of the proposed immunosensor decreased linearly with the increase of SAL concentration when the immune-reaction was carried out with anti-SAL,and the relationship between the peak current and SAL concentration was established to accomplish the quantitative detection on SAL.The experimental factors affecting current response were explored,including pH of phosphate buffer solution (PBS),incubation temperature and incubation time.Under the optimized conditions,the linear range of the immunosensor was obtained to be 1.0-100 μg/L with a limit of detection(LOD) of 0.67 μg/L(3σ/k).With the advantages of good reproducibility,specificity and stability,the immunosensor was successfully applied in the detection of SAL in swine feed and pork samples with satisfactory results.The recoveries of SAL in swine feed and pork were in the ranges of 100.2%-102.4% and 97.5%-103.3% with relative standard deviations(RSDs) of 1.9%-4.7% and 2.1%-3.5%,respectively.关键词：acetylene black;alizarin;Au NPs;salbutamol;titanium dioxide
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发布时间： - 摘要：A fluorescence sensor based on porphyrin-infiltrated SiO2 IOPCs(TPP-SiO2 IOPCs) was prepared by introducing inverse opal photonic crystals(IOPCs) in the traditionally corrosive gas detection system.The fluorescence enhancement of TPP-SiO2 IOPCs for hydrochloride(HCl) gas detection was up to 200-fold in comparison to that for the control sample,which was mainly attributed to the slow photon effect of photonic crystals and the large surface area of inverse opal structure.Furthermore,the quenching efficiency of the TPP-SiO2 IOPCs achieved 75%after exposure to HCl gas,whereas it was only about 50%to the control sample.Moreover,the initial emission intensity was almost recovered by simply exposing the TPP-SiO2 IOPCs to ammonia(NH3) gas.The quenching efficiency and regeneration performance of the TPP-SiO2 IOPCs sensor remained nearly unchanged over five cycles of use,demonstrating its excellent reusability.The results suggested that TPP-SiO2 IOPCs sensor provided a new idea for the development of highly efficient fluorescence sensors.关键词：porphyrin;inverse opal photonic crystals(IOPCs);fluorescence;HCl gas
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发布时间： - 摘要：Vitamin E is a natural antioxidant with important physiological functions,which content in food seems so significant to determine.Sample pretreatment toward vitamin E is essential as it is the most important procedure which will take the longest time during separation and determination.Under this circumstance,the efficiency,validity and reliability of evaluation on natural vitamin E mainly depend on sample pretreatment,i.e.extraction methods.In recent years,a lot of work has been done in this field,and a great variety of novel extraction methods for vitamin E have been developed,which have been verified to be simple,effective and reliable.In this paper,the extraction methods such as saponification,direct solvent extraction,pressurized liquid extraction,supercritical fluid extraction,solid phase extraction and their applications are briefly reviewed,their merits and drawbacks are also summarized.In the end,the development tendency for sample pretreatment is proposed.关键词：natural vitamin E;sample pretreatment;progress
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