最新刊期
卷 32 ， 期 5 ， 2013
- 摘要：In this study，the pyrolysis vapors of asparagine under different pyrolytic conditions were analyzed by analytical pyrolysis/gas chromatography-mass spectrometry(Py/GC-MS).In addition，by using the amide 15N labeled asparagine sample and analysis of label incorporation of the major nitrogen contained compounds，the influence of pyrolysis conditions on the formation pathways of the major pyrolysis products of asparagine were elucidated.The results indicated that pyrolysis temperature has a significant impact on the decomposition of asparagine.The yields of major products at low and high temperature are strikingly different.The yields of maleimide and succinimide，which are the predominant pyrolysis products of asparagine，increased strikingly as the pyrolysis temperature increased from 300 ℃ to 600 ℃，while in contrast，from 600 ℃ to 900 ℃，the peak area of maleimide increased slowly but succinimide starts to decrease.The yields of amides and acidic compounds increased monotonically with the increase of the pyrolysis temperature，and the formation of nitriles and pyrroles were favored at higher heating temperatures.Furthermore，pyrolysis temperature has a significant effect on the formation pathways of the major pyrolysis products of asparagine.Most of the nitrogen in maleimide and acetamide originate from the 15N-labeled amide group of asparagine at low temperature，while from the unlabeled amino group at high temperature.The nitrogen atoms of the three nitrile compounds，hydrogen cyanide，acetonitrile and acrylonitrile are mainly from the unlabeled amino group，especially at higher temperature.By contrast，the influences of pyrolysis atmosphere and time on the yields and formation pathways of the major products of asparagine are much less.关键词：asparagine;Py/GC-MS;pyrolysis conditions;influence
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发布时间： - 摘要：The 55.2-138.2 ℃fraction of coal direct liquefaction hydrogenation modification oil was cut out by distillation tester of petroleum products SYD-6536C，and a method was developed for the analysis of 55.2-138.2 ℃fraction of coal direct liquefaction hydrotreated oil by heart-cutting two-dimensional GC-MS.A PONA capillary chromatographic column（50 m×200 μm×0.5 μm） was used for chromatographic condition optimization，and the best chromatographic separation condition for 55.2-138.2 ℃ fraction of coal direct liquefaction hydrotreated oil were obtained.The oil sample would be separated on the first capillary chromatographic column in the best experimental conditions.Then the target compounds were cut out to the second chromatographic column（DB-35MS,30 m×250 μm×0.25 μm） by Dean Switch micro flow control system，which would get further separation.The identification was based on hydrocarbon compounds retention rules on PONA，compound retention index，standard compound retention value and mass spectra library searching.With those methods，66 compounds of 55.2-138.2 ℃ fraction of coal direct liquefaction hydrotreated oil were identified.Ignoring the effect of compounds relative correction factor due to the similar compounds structure properties in the oil sample，the area normalization method was used for the quantitative analysis.The proposed method was simple，rapid and accurate，and could be used for composition determination of light petroleum distillate of coal direct liquefaction hydrotreated oil.Also the method provides reference for detailed analysis of high petroleum distillate of coal direct liquefaction hydrotreated oil and other oil sample.关键词：heart-cutting;two-dimensional gas chromatography;identification by retention time;coal direct liquefaction hydrogenation modification oil
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发布时间： - 摘要：Effect of argon ion bombardment on copper oxide was investigated by in situ X-ray photo-electron spectroscopy(XPS).It turned out that CuO can be reduced under extremely weak argon ion beam condition.At the initial stage of the whole bombardment process,Cu2p XPS spectra and CuLMM Auger spectra changed drastically.The final chemical state is the coexistence state of CuO and Cu2O with a small amount of Cu by analyzing Cu2p and CuLMM Auger peaks.The important reference values were obtained for the determination of the chemical states in the depth analysis of copper oxide.关键词：CuO;argon ion bombardment;X-ray photoelectron spectroscopy(XPS);reducti
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发布时间： - 摘要：A novel grapheme-based solid phase microextraction(SPME) fiber was prepared by coating graphene composite onto the surface of a treated copper wire using sol-gel method,and was applied in the direct determination of dioxin-like polychlorinated biphenyls(DL-PCBs) in the environmental samples，combining solid phase microextraction-gas chromatography-electron capture detector(SPME-GC-ECD) technology.The parameters influencing the extraction and efficiency,including extraction temperature,extraction time,sample pH,salt concentration and desorption time,were optimized.Under the optimized conditions,the chromatographic peak areas obtained from the grapheme-based fiber extracting twelve DL-PCBs were averagely two times higher than those obtained from the commercial fibers such as 100 μm PDMS,75 μm CAR/PDMS,85 μm PA.The grapheme-based fiber showed good linearity for DL-PCBs in the range of 0.05-3.5 μg?L-1 with correlation coefficients higher than 0.99 except PCB169(r2=0.987 4).The limits of detection(LODs) were in the range of 4.7-8.8 ng?L-1.The relative standard deviations(RSDs) were 1.4%-8.1% for a single fiber and 2.4%-12.8% for fiber-to-fiber.The average recoveries of twelve DL-PCBs were in the range of 87%-120% with spiked levels of 0.5 μg?L-1 for DL-PCBs standard in the environmental water samples and 2 ng?g-1 in the environmental mud samples.The proposed method was simple,sensitive and rapid, and could be used for the detection of trace amount of DL-PCBs.关键词：solid phase microextraction;graphene;polychlorinated biphenyls;environmental sample
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发布时间： - 摘要：A novel strong cation exchange monolithic column was prepared in a stainless steel column（4.6 mm in diameter） via the free radical polymerization of sodium methyl allyl sulfonate（SMAS） as monomer and ethylene glycol dimethacrylate（EDMA） as crosslinking agent.Scanning electron microscope image showed the resultant monolithic column matrix exhibited a continuous,porous and uniform structure.The on-line cleanup solid phase extraction was realized on the monolithic column and the determination of clenbuterol in pork was carried out by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The result indicated that clenbuterol in pork sample was effectively enriched and purified by the prepared monolithic column.The calibration curve was linear in the range of 0.05-10.0 μg/L for clenbuterol with a correlation coefficient of 0.998 8.The limit of detection（LOD） for clenbuterol in pork was 0.5 μg/kg,which agreed with the standards regulated by the National Standards of the People’s Republic of China.The average recoveries at three spiked levels of 0.5,1.0，5.0 μg/kg were 91%,94%and 96% with relative standard deviations（RSDs） of 4.9%,4.5% and 3.4%,respectively.With advantages of simplicity,reliable and sensitivity,the method was successfully applied in the determination of clenbuterol in pork samples.关键词：monolithic column;strong cation exchange;on-line cleanup;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;clenbuterol
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发布时间： - 摘要：In this paper，the detection of the high blood glucose（BG） volunteers characteristics VOCs in breath gas was performed with a homemade PTR-MS.An improved real time online breath analysis system was used for the analysis of 70 normal volunteers and 22 volunteers who suffered from BG.The date were statistically analyzed by Mann-Whitney U test and linear discriminant stepwise regression.The five product ions of VOCs which showed significant differences between the two groups were identified.The mass to charge ratio（m/z） of the five VOCs were m/z 61,31,120,104 and 82，respectively.The five VOCs diagnostic values were evaluated by Receiver operating characteristic（ROC） curve.The area under ROC（AUC） was 0.926，and the specificity and sensitivity were 84.3% and 86.4%，respectively.This paper also focused on the investigation of the acetone concentration distribution in the two groups of volunteers breath gas，and the statistical analysis results showed that the acetone in two groups had no significant difference，and the acetone concentration and blood sugar concentration had also no significant correlation.关键词：high blood glucose;breath biomarkers;PTR-MS;VOC;non-invasive analysis
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发布时间： - 摘要：In this paper,from the angle of quantitative fingerprint,the volatile constituents of Herba Houttuyniae(HH) obtained from three different origins(Boluo County of Guangdong Province,Dali City of Yunnan Province and Changsha County of Hunan Province) were investigated comparatively by gas chromatography-mass spectrometry(GC-MS) combined with HELP method,and the overlapping chromatographic peaks were analyzed.The results showed that,the differences in the volatile chemical compositions of HH from three different origins are mainly embodied in the relative contents of most compounds,including terpinen-4-ol,α-terpineol,sabinen,β-myrcene,etc.The relative contents of terpinen-4-ol in three different origins were 0.19%-0.24%,4.47%-4.93%and 0.03%-0.07%，respectively,the relative contents of α-terpineol were 0.17%-0.27%,0.22%-0.24% and 0.07%-0.09%,respectively,the relative contents of sabinen were 0.48%-0.64%,25.2%-26.8% and 0.07%-0.11%,respectively,the relative contents of β-myrcene were 33.66%-43.36%,10.11%-11.11% and 51.23%-55.39%,respectively.This study can provide some reliable foundation for volatile components of Herba Houttuyniae in regulating the pharmaceutical products and the practical application.关键词：Herba Houttuyniae(HH);volatile constituents;quantitative fingerprint;gas chromatography-mass spectrometry(GC-MS);overlapping chromatographic peaks
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发布时间： - 摘要：An electrospray ionization-high resolution mass spectrometric（ESI-HRMS） method was developed for the determination of thermolabile N,N-dimethylaminomethyl ferrocene compounds.The relative standard deviation（RSD，n=10） for the ion counts of the target molecule was 2.4%.By analysis of the MS spectrum and MS/MS spectrum of the target molecule，it is showed that an in-source dissociation of the target molecule took place with the abundance of the mother ion being less than 10% of the abundance of the main daughter ion in the MS spectrum.The relevance of ion counts of the target molecule and its main daughter ion with temperature of the drying gas and voltage of the capillary export（Fragmentor） were investigated，respectively.Furthermore，corresponding fitting mathematical equations were established，and the optimum analytical conditions of the target molecule by ESI-HRMS were obtained.关键词：ESI-HRMS;Q-TOF mass spectrometry;N,N-dimethylaminomethyl ferrocene
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发布时间： - 摘要：A method was developed for the simultaneous determination of 7 residual benzene series（BTEX）,including benzene,toluene,ethylbenzene,p-xylene,m-xylene,o-xylene and styrene，in resin crafts by headspace gas chromatography（HG-GC）.The extraction conditions,including solvent type,extraction temperature and time,were investigated,and the chromatographic conditions for HS-GC,including headspace bases,equilibrium temperature and time,sample granularity,were optimized.The results showed that 7 residual benzene series were preferably separated and good quantitative analyses were achieved under the headspace equilibrium temperature at 130 ℃ for 60 min,where the diameter of sample particle was smaller than 2mm and the DB-WAX capillary operation was chosen.Under the optimal conditions，the calibration curves were linear in the range of 0.1-500 μg with correlation coeficients higher than 0.999．The limits of quantitation（LOQs,S/N=10） of this method were between 0.1 μg?g-1 and 0.4 μg?g-1.The recoveries at three spiked levels ranged from 93% to 114% with relative standard deviations（RSDs） of 0.7%-4.8%.The established method was rapid and accurate,and was suitable for the analysis of benzene series in resin crafts.关键词：headspace;gas chromatography;resin crafts;benzene series
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发布时间： - 摘要：A kind of 2D-［Zn（benzotriazole）2］n coordination polymer was synthesized,and used to concentrate and extract six heavy polycyclic aromatic hydrocarbons（PAHs） in environmental water samples.The prepared coordination polymer was characterized by X-ray powder diffraction（XRD）,scanning electron microscope（SEM） and elemental analysis,and the polymer showed a strong affinity to aromatics.In the experiment, amount of coordination polymer, washing solvent, kind and usage of eluent, flow rate and breakthrough volume were all investigated.The final result was compared to the C18 solid phase extraction（SPE） column with the same sample volume and spiked level,thus an analytical method by gas chromatography-mass spectrometry（GC-MS） was established to determinate six PAHs in water samples.A good extraction efficiency could be obtained by using 200 mg coordination polymer as SPE adsorbent,10% methanol as washing solvent,0.5 mL acetone and 5 mL dichloromethane as eluent,with a flow rate of 4 mL/min and a sample volume of 200 mL.Good linearities were obtained over the ranges of 20-1 000 μg/L for fluranthene（Flan）,benzo［b］ fluoranthene（BbF） and benzo［g,h,i］perylene（BghiP）,and 10-500 μg/L for benzo［k］ fluranthene（BkF）,benzo［a］pyrene（BaP） and indeol［1,2,3 Cd］pyrene（InP）,with correlation coefficients（r2） of 0.996 8-0.999 3.The detection limits ranged from 0.45 ng/L to 10.7 ng/L.The spiked recoveries of six PAHs were in the range of 77%-112% with RSDs of 3.8%-8.5%.The established method showed advantages of low-cost and high-sensitivity,and could meet the requirements for determination of six PAHs in real environmental water samples.关键词：coordination polymer;SPE;GC-MS;PAHs;water sample
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发布时间： - 摘要：An electrochemical sensor based on dropped molecular imprinted polymers（MIPs） suspension for dopamine was fabricated.Influences of pH value,concentrations of graphene and MIPs were also optimized.The optimal conditions were as follows:pH value:7.0，concentration of graphene:0.5 g/L,concentration of MIPs:20 g/L.Under the optimal conditions,the prepared sensor showed good selectivity and high sensitivity for dopamine.The DPV peak current is linear to the DA concentration in the range of 2.0×10-7-1.0×10-4 mol/L，with a detection limit（S/N=3） of 6.8×10-8 mol/L.The prepared sensor was successfully applied in the determination of dopamine hydrochloride with recoveries of 98%-105%．关键词：graphene;dopamine;molecular imprinted polymers(MIPs);electrochemical sensor
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发布时间： - 摘要：In this paper,viscous methylmethacrylate（MMA） was prepolymerized as an hand mixed adhesive for the fabrication of a composite graphite/poly（methylmethacrylate） electrode with high electrochemical performance.Compared with the traditional carbon paste electrode,the electrode fabricated behaves better in mechanical property,stability and reproducibility.The behavior of nonyl phenol（nP）at composite graphite/PMMA electrode was studied by SEM and impedance spectroscopy.Factors influencing the detection processes of nP such as supporting electrolyte,pH value and scan rate were also investigated and optimized.The results indicated that an adsorption-controlled process with 2 electrons and 2 protons transfer occurred at the proposed electrode and the oxidation process for nP was completely irreversible.Under the optimized conditions,a sensitive method of amoperometric measurement was established for the detection of nP at the graphite/PMMA composite electrode.The calibration curve was linear over the nP concentrations in the ranges of 5.0×10-8-7.0×10-7 mol/L（r=0.998）and 9.0 ×10-7-3.0×10-5 mol/L（r=0.996） with a detection limit（S/N=3） of 6.62×10-9mol/L.The proposed method was simple and rapid,and was applied in the determination of nP in real water and soil samples with good recoveries of 94%-103%.关键词：nonyl phenol;graphite / PMMA composite electrode;electroanalysis
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发布时间： - 摘要：A method of capillary electrophoresis(CE) was developed for the analyisi of the optical purity of eight aromatic alcohols with different substituent groups using mono-6-ammonium-6-deoxy-β-cyclodextrin chloride(β-CD-NH3Cl) as chiral selector.The separation conditions were optimized through investigation of effects of concentration of β-CD-NH3Cl and background electrolyte,pH value of buffer,running voltage,etc.Under the optimized conditions,the eight samples of aromatic alcohol were successfully separated.The optical purities of the eight aromatic alcohol enantiomers were investigated by CE method,and the results were evaluated by comparion with those obtained by the HPLC method.The results showed that the enantiomers excesses(e.e%) of three batches of samples determined by CE were consistent with those by HPLC.This method is simple and accurate,and could be applied in the chiral separation of eight aromatic alcohol enantiomers and the determination of e.e%.关键词：aromatic alcohol;mono-6-ammonium-6-deoxy-β-cyclodextrin chloride;chiral separation;optical purity;capillary electrophoresis
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发布时间： - 摘要：A novel method for the enrichment and determination of trace dimethyl phthalate(DMP）,diethyl phthalate(DEP）,di-n-butyl phthalate(DBP）,di（2-ethylhexyl） phthalate(DEHP） and di-n-octyl phthalate(DOP） in environmental water by ultrasound assisted dispersive liquid-liquid microextraction(DLLME） combined with high performance liquid chromatography(HPLC） was established.Experimental conditions of chromatographic separation and DLLME such as type and volume of extractants and disperser solvents,ultrasonic microextraction time and ionic strength were examined.Under the optimized conditions,the chromatographic peak areas were proportional to the concentrations of phthalates in the range of 1.00-100 μg/L with correlation coefficients more than 0.996.The average recoveries were in the range of 91%-103% with relative standard deviations(RSDs,n=5） of 2.0%-6.8% for the water sample at a spiked level of 20.0 μg?L-1.The limits of detection were 0.08,0.04,0.03,0.01,0.07 μg?L-1,respectively.This method was applied in the enrichment and determination of 5 phthalates in the real water samples with average recoveries of 85%-119% and RSDs(n=3） of 2.3%-11.1%.The developed procedure is suitable for the enrichment and determination of trace phthalates in different real environmental water samples.关键词：dispersive liquid-liquid microextraction;high performance liquid chromatography;phthalates;enrichment;sample preparation
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发布时间： - 摘要：A new ACE inhibitory peptides database was self-established.After the structures of peptide samples with different lengths were characterized using amino acid descriptors SVHEHS,the data obtained were treated for standardization by auto cross covariances（ACC）.Then three modeling methods,namely multiple linear regression（MLR）,partial least squares（PLS） and artificial neural network（ANN） were used to establish the models of the QSAR of ACE inhibitory peptides,respectively.The results showed that R2（correlation coefficient） of MLR,PLS and ANN models were 0.744,0.862 and 0.958,Q2LOO（leave-one-out cross-validated correlation coefficient） were 0.532,0.829 and 0.948,and Q2ext（external validated correlation coefficient） were 0.567,0.632 and 0.634,respectively.Hence,the combinations of SVHEHS and the above three modeling approaches were all useful for the QSAR of ACE inhibitory peptides,in which ANN modeling approach is the best.关键词：angiotensin I-converting enzyme inhibitory peptides;quantitative structure activity relationship;multiple linear regression;partial least square regression;artificial neural networks
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发布时间： - 摘要：By analysis of mass spectra of sibutramine and an unknown compound in a health supplement for anti-obesity,this paper proposed the mass fragmentation pathways of sibutramine and the unknown compound,and deduced the structure of the unknown compound by piecing together fragments of the compound detected on a high-resolution mass spectrometry.The compound of the structure was synthesized and its structure was elucidated by analysis of elements,infrared spectrometry,mass spectrometry and nuclear magnetic resonance.With the synthesized compound as the reference substance,a verification examination of the sample was performed by HPLC-MS/MS.The results indicated that a new sibutramine analogue was adulterated in the sample.The study provided an effective strategy in detection and verification on analogues of synthesized drugs adulterated in health supplements.关键词：healthy products;illegal adulteration;sibutramine analogues;ESI-MS/MS detection and verification
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发布时间： - 摘要：The self-assembled and film-forming processes of n-dodecyl mercaptan solution,t-dodecyl mercaptan solution and mixed solution of n- and t-dodecyl mercaptans on copper surface were investigated.The corrosion resistances of the self-assembled films formed in three kinds of solutions on copper surface using electrochemical techniques such as AC impedance and polarization curves,were tested.The connection between the quality of the self-assembled film of n-dodecyl mercaptan solution and concentration of the solution,and the assembly time were discussed.The results indicated that the self-assembled film formed in the mixed solution of n- and t-dodecyl mercaptans on copper surfaceshowed a much better advantage in both quality and corrosion resistance than that formed in only n- or t-dodecyl mercaptan solution.关键词：n- and t-dodecyl mercaptan;copper surface;self-assembled films
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发布时间： - 摘要：A method combining hydrophilic interaction liquid chromatography(HILIC） with tandem mass spectrometry(MS/MS） was developed for the determination of cartap residue in tea.The target analyte was extracted with acetonitrile-methanol-acetate acid(93∶5∶2） and cleaned up using solid phase extraction(SPE） cartridge with C18 or dispersive solid phase extraction(d SPE） with GCB and C18.The analyte was separated on a ZIC HILIC silica column by a gradient elution of acetonitrile and 10 mmol/L ammonium acetate.A tandem mass spectrometry with electrospray ionization(ESI） was employed to detect cartap using multi-reactionmonitoring(MRM） mode.The matrix effect depended on tea categories and matrix content.A satisfactory linearity（r2≥0.998） was obtained in the concentration range of 0.005-0.5 mg/L.The limits of quantitation(LOQs） for green tea and black tea were 0.008 mg/kg and 0.005 mg/kg，respectively.The method was validated at the spiked levels of 1LOQ，5LOQ and 10LOQ in green tea and black tea，and the recoveries ranged from 70% to 89% with relative standard deviations(RSDs） less than 6%.The results demonstrated that the method was sensitive and accurate，and was suitable for the determination of cartap residue in tea.关键词：hydrophilic interaction chromatography-tandem mass spectrometry(HILIC-MS/MS）;cartap;tea;matrix effect
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发布时间： - 摘要：An ultra-high performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was established for the determination of 27 pesticide residues in raisins,include carbamate insecticides,triazole fungicides and other fungicides,pesticides.The samples were directly extracted with 0.1% glacial acetic acid-acetonitrile,and purified by QuEChERS method.The analysis of 27 pesticides was carried out under positive electrospray ionization(ESI+) mode and multiple reaction monitoring(MRM) mode,quantified by matrix matching curve external standard method.The results showed that the calibration curves of 27 pesticides were linear(r≥0.993) in the concentration range of 5-100 μg/kg.The average recoveries at three spiked levels of 10,20 and 50 μg/kg were in the ranges of 60%-97%,62%-97% and 64%-99%,respectively,with relative standard deviations(RSDs) of 3.0%-13.0%,1.6%-9.6% and 3.3%-9.6%,respectively.The quantitation limit(S/N≥10) was 10 μg/kg.The method is simple,rapid,sensitive and accurate,and was suitable for the confirmation and quantitative determination of multiple pesticide residues in raisins.关键词：raisins;variety of pesticide residues;UPLC-MS/MS;QuEChERS method
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发布时间： - 摘要：A GC-MS/MS was used to study the migration of 3 plasticizers(i.e.DIBP,DEHP and DEHA) in PVC plastics into olive oil after microwave heating.The influences of the heating time and the power of microwave on the migration of plasticizers were studied,and comparation between microwave heating and traditional with water bath was made.The results showed that the migration was increased with the increase of the power of microwave and heating time.When the heating time is the same,the migration of plasticizers into olive oil under microwave heating was noticeably higher than that by the traditional heating.关键词：GC-MS/MS;microwave;plasticizers;olive oil;migration
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发布时间： - 摘要：A high-performance liquid chromatographic(HPLC) method was developed for the determination of relative substances in diclofenac sodium gel.The separation of analyte was performed on a Waters XBridge column(5 μm,150 mm×4.6 mm) at a flow rate of 1.0 mL/min and an injection volume of 5 μL,by a gradient elution using pH 2.0 trifluoroacetic acid - methanol(80∶20) as mobile phase A and acetonitrile - methanol(80∶20) as mobile phase B.The photo-diode array detector(PDA) was set at 254 nm.The column temperature was 30 ℃.Under the above chromatographic conditions, the calibration curves were linear in the range of 1.0-40.0 mg/L with correlation coefficients more than 0.99.The recoveries for all the specified impurities ranged from 97% to 104% with RSDs not more than 3.8%.The proposed method could be applied in the determination of relative substances in diclofenac sodium gel containing alcohols excipients with the advantages of simplicity,rapidity,accuracy,good selectivity and high sensitivity.关键词：diclofenac sodium gel;relative substances;specified impurities;HPLC
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发布时间： - 摘要：The anisaldehyde dimethyl acetal （p-MBDMA） that produced by direct electrochemical oxidation synthesis in the anhydrous KF-CH3OH system is easily hydrolyzed in water.The study results indicated that p-MBDMA could be hydrolyzed into anisaldehyde raidly and completely in the acidic mixed solution of methanol，acetonitrile and water.Based on this，a high performance liquid chromatographic （HPLC） method was developed for the determination of p-MBDMA indirectly.The best mobile phase was a mixture of water-methanol-acetonitrile（50∶30∶20，adjusted pH 3.0 by phosphoric acid）.The internal mechanism of p-MBDMA in the column was also investigated.The results showed that HPLC method could be successfully applied in the rapid determination of p-MBDMA content.关键词：HPLC;electrochemical oxidation synthesis;anisaldehyde dimethyl acetal;anisaldehyde;indirect determination
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发布时间： - 摘要：Chromatography is widely-used analysis technique today.However,in the traditional off-line chromatographic analysis procedures,the sampling,sample pretreatment and chromatographic analysis are conducted independently.These off line procedures are solvent-wasted,time and labor consumed,easy to produce error and lead to low recovery.On-line coupling method could tackle the above problems,and has become the front project in the field of analytical chemistry.The design consideration of the on-line coupling techniques in the chromatographic analysis was discussed in this review.Furthermore,the related techniques and the latest progresses in this field were summarized.关键词：sample preparation;chromatography;on-line analysis;progress
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