最新刊期
卷 30 ， 期 6 ， 2011
- 摘要：The surface sediment samples from sixteen stations of Zhifu Bay，the Yellow Sea，were collected in July 2009 and the concentrations of eight heavy metals，including Hg，Cu，Pb，Cd，Zn，Ni，Co and Mn were determined. The results showed that the concentrations of heavy metals in Zhifu Bay were generally low，which were less than the national standard levels of grade I sediments. The average concentrations of Hg，Cu，Pb，Cd，Zn，Ni，Co，Mn were 0.02，12.3，8.67，0.13，32.8，11.4，5.00，229 mg·kg-1，respectively. The pollution levels and potential ecological risk levels of heavy metals were evaluated by geoaccumulation index and Hakanson′s method，and the results demonstrated the pollution and potential ecological risks of Hg and Cd were higher than those of the other metals. The levels of heavy metals in this survey were generally lower than that of the previous study，suggesting an improvement of marine environments in recent years.关键词：heavy metals;marine environment;Zhifu Bay;the Yellow Sea;potential ecological risk
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发布时间： - 摘要：The mode of interaction of emodin and DNA was studied through fluorescence analysis,UV-visible absorption spectra,viscosity measurement and competition experiments with ethidium bromide.When the optimal conditions were set as follows: pH 7.4,ionic strength of 30 mmol/L NaCl,temperature of 37 ℃ and reaction time of 35 min,the fluorescence intensity of emodin was decreased with the increase of DNA concentration.The isosbestic points（380 nm and 475 nm） of emodin was red shifted by 5 nm in the presence of DNA,indicating that the complex of emodin and ctDNA was formed.Meanwhile,the fluorescence spectra of adenine and DNA showed the similar fluorescence quenching to that of DNA,indicating that emodin was embedded in base pairs and the hydrogen bond between adenine and cytosine was damaged.关键词：emodin;DNA;intercalate;fluorescence;UV-Vis absorption spectrum;ethidium bromide;quenching
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发布时间： - 摘要：A silver doped modified montmorillonite was made by octadecyl trimethyl ammonium bromide（STAB） and ［Ag（NH3）2］OH,and characterized by X-ray diffraction,scanning electron microscopy and AC impedance method.The electrochemical behavior of hydroquinone on the electrode modified by the montmorillonite was investigated by cyclic voltammetry（CV）and some important kinetic parameters of the electrochemical process were determined.The results indicated that the anode process of hydroquinone at electrode was controlled by adsorption-diffusion,and the cathodic process was controlled by diffusion.The number of electron transfer was equal to the number of protons（n=m=2）,and the transfer coefficients α equals 0.658 8 and β equals 0.341 2.The effective area of Ag STAB-MMT/GCE（Aeff）was 0.026 4 cm2,and the diffusion coefficient（D）was 6.34×10-5 cm2/s.The correlation between the peak current and concentration was investigated by square wave voltammetry（SWV）.A good linearity was obtained between the peak current and the concentration of hydroquinone in the range of 4.0×10-6~5.0×10-4 mol/L,with a detection limit of 1.13×10-7 mol/L.The method was applied in the determination of hydroquinone in real water with spiked recoveries of 100%-108%.The modified electrode showed good reproducibility and stability.关键词：hydroquinone;modified montmorillonite;circle voltammetry;square wave voltammetry;electrochemical behavior
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发布时间： - 摘要：he calibration set and prediction set were configured according to the central composite design,then PLS and PCR were applied on zero and first order derivative spectra of the mixture of three components——aspirin,paracetamol and salicylic acid.And the derivative spectrophotometric multivariate calibration methods were used for the simultaneous measurement of the mixture.The results showed that the absorption spectra of aspirin,paracetamol and salicylic acid overlapped seriously.Derivative ratio spectrophotometry could not simultaneously measure the content of each component in the mixture since the zero crossing points of the components overlapped.The derivative spectrophotometric multivariate calibration methods could effectively prevent the zero crossing points of the individual components from coinciding in linear range.The average relative errors of all components in the prediction set were below 3.6%,and the average recoveries were 101%.Each component of the real pharmaceutical samples also had exact prediction results.With good sensitivity and the limit of detection,the derivative spectrophotometric multivariate calibration methods could be used to measure simultaneously the contents of the three components in drug synthesis and quality inspection.关键词：aspirin;paracetamol;salicylic acid;PLS;PCR;derivative spectrophotometry;derivative ratio spectrophotometry
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发布时间： - 摘要：A high performance liquid chromatography coupled with electro spray ionization tandem mass spectrometric（HPLC-ESI MSn） method was developed for the simultaneous determination of psoralen and bergapten in aqueous extraction from Radix fici hirtae.The separation of psoralen and bergapten was performed on a Hypersil C18 column（150 mm×4.6 mm,5 μm）,using water-methanol（50∶50）as mobile phase at a flow rate of 0.80 mL·min-1.The detection was carried out at room temperature with a detection wavelength of 300 nm（PDA） and an injection volume of 10 μL.The influencing factors for liquid-liquid microextraction（LLME） were investigated.Under the optimized conditions,the calibration curves were linear in the range of 0.55-2 200 μg·L-1 for psoralen and 1.00-4 000 μg·L-1 for bergapten,with correlation coefficients of 0.999 9 and 0.999 2,respectively.The limits of detection（S/N=3） were 0.13 μg·L-1 and 0.18 μg·L-1，and the limits of quantitation（S/N=10） were 0.43 μg·L-1 and 0.60 μg·L-1, respectively.The relative standard deviations（RSDs,n=5） of 110 μg·L-1 psoralen and 100 μg·L-1 bergapten were both less than 1%.The recoveries of psoralen and bergapten were 100% and 101%,respectively.The results demonstrated that LLME combined with LC-MS was a rapid,convenient and efficient method for the determination of herbal compositions,and could provide the basis for the quantitation detection of psoralen and bergapten in aqueous sample from Radix fici hirtae.关键词：Radix fici hirtae;liquid-liquid microextraction（LLME）;high performance liquid chromatography-mass spectrometry（HPLC-MS）;psoralen;bergapten
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发布时间： - 摘要：31 inorganic phosphorus containing compounds and 84 organic phosphorus containing compounds were collected，and the 31P NMR spectra database of phosphorus containing compounds was established for the first time.A method based on the spectra database was developed for the rapid determination of phosphorus containing compounds in detergents by 31P NMR.Phosphorus containing compounds in several kinds of washing powder，metal cleaning agents and deoiling agents were detected by NMR.By comparing the 31P NMR spectra of the tested samples with that of the standard，the structures of phosphorus containing compounds in detergents were identified.The results showed that，under the presented conditions，three phosphorus containing compounds e.g.sodium tripolyphosphate，sodium pyrophosphate and disodium hydrogen phosphate were detected in one kind of washing powder.Only one phosphorus containing component （phosphoric acid） was detected in all three metal cleaning agents.And the phosphorus containing components of three deoiling agents were detected to be phosphate polyoxyethylene nonylphenol，sodium tripolyphosphate and disodium hydrogen phosphate,as well as sodium tripolyphosphate,sodium phosphate and dipotassium hydrogen phosphate，respectively.The proposed method could also be applied in the analysis of other phosphorus containing fine chemical products with the advantages of simplicity，accuracy and rapidity.关键词：31P NMR;phosphorus containing compounds;detergents;chemical shifts
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发布时间： - 摘要：Molecularly imprinted polymers（MIPs）were synthesized by bulk polymerization and swelling polymerization using nicotinic acid（NA）as the imprinted molecule, 4-vinylpyridine（4-VP） as the functional monomer and ethyleneglycol dimethacrylate（EGDMA） as the cross linker, initiated thermally with azobisisobutyronitrile（AIBN）. The binding and selectivity of MIPs to NA and different substrates were evaluated by the static batch method. The adsorption amounts of MIP1 and MIP2 were 193.56 μmol/g and 215.35 μmol/g, respectively, which were obviously higher than those of their corresponding non imprinted polymers,NIP1 and NIP2.The adsorption capacity of niacinamide on MIPs was the largest, followed by benzoic acid, benzyl alcohol and 3 pyridine methanol. The results indciated that the stereostructure of the substrate and the interactions between substrate and imprinting bites influenced the recognition property of MIPs.关键词：molecularly imprinted polymers;nicotinic acid;mechanism of recognition;bulk polymerization;swelling polymerization
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发布时间： - 摘要：An analytical method was developed and validated for the simultaneous determination of 3 tetracyclines and 2 quinolones in pork and chicken by ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） by positive ion mode under multiple reaction monitoring （MRM）.The sample were extracted by ultrasonic extraction in Mcllvaine-Na2EDTA buffer （pH 4.0）.The extract was cleaned up on a solid phase extraction（SPE） cartridge packed with multiwalled carbon nanotubes（MWCNTs） and using formic acid- acetonitrile（5∶95，by volume） mixture as eluting solvent.The drugs residues were analyzed by UPLC-MS/MS.The analysis time was only 10 min.Good linearities were obtained in the range of 5-500 μg/L.The limit of detection （LOD） was 15 μg/L for chlortetracycline（CTC） and 5 μg/L for the other four drugs.The recoveries at spiked levels of 50,100,200 μg/L ranged from 76% to 90% for 5 drugs with relative standard deviations（RSDs） less than 9%.With good stability and high sensitivity,the method could be used for the rapid determinaion of these drug residues in pork and chicken sample.关键词：multiwalled carbon nanotubes（MWCNTs）;ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）;tetracyclines;quinolones;pork;chicken
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发布时间： - 摘要：A rapid method of liquid chromatography tandem mass spectrometric（HPLC-ESI MS/MS） with isotope dilution was developed for the simultaneous determination of residual mebendazole（MBZ） and its metabolites e.g. hydroxy mebendazole（MBZ-OH） and amino menbendazole（MBZ-NH2） in fishery products.The sample,after adding disodium phosphate,was extracted with ethyl acetate.The extract was evaporated to dryness under nitrogen,and redissolved in 2 mL methanol-0.1% formic acid（1∶1,by volume）.The solution was defatted with n hexane.The targeted compouds were seperated on Hypersil GOLD C18 column（100 mm×2.1 mm i.d.,3 μm） using methanol-0.1% formic acid as mobile phase at a flow rate of 0.2 mL/min,and analyzed by a triple quadrupole tandem mass spectrometer with a heated electrospray ionization source（HESI） and selected reaction monitoring（SRM）.The standard curves were linear in the range of 0.5-100 μg/L for three analyzed drugs with correlation coefficient（r2） not less than 0.999 2.At spiked levels of 1-40 μg/kg in grass carp,crayfish and soft shelled turtle blank muscle sample,the average recoveries of MBZ,MBZ-OH and MBZ-NH2 ranged from 91% to 112% with their relative standard deviations（RSDs） of 1.5%-10.7%.The detection limits for all the target compounds were 0.5 μg/kg and the quantitation limits were 1.0 μg/kg.The results showed that the method was simple,sensitive and accu rate,and was suitable for the simultaneous qualitative and quantitative confirmations of menbendazole and its metabolites residues in fishery products.关键词：isotope dilution;menbendazole;hydroxy mebendazole;amino menbendazole;metabolites;HPLC-MS/MS;fishery products
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发布时间： - 摘要：A high performance liquid chromatography-tandem mass spectrometric method was developed for the determination of tolfenpyrad，flonicamid,chlorantraniliprole and flubendiamide in vegetables and fruits.The samples were extracted with acetonitrile and purified by QuEChERS method after salting out.The solution after purification was evaporated to dryness in a water bath at 40 ℃ under nitrogen and redissolved with 1 mL acetonitrile-water （20∶80,by volume）.The compounds were analyzed by LC-MS/MS on an XBridgeTM C18 column using acetonitrile-0.1% formic acid as mobile phase by gradient elution.The mass spectrometer was operated under multiple reaction monitoring（MRM） mode with the positive ionization mode.Good linearities were obtained in the concentrations of 0.075-2.0 mg·L-1 for tolfenpyrad and flonicamid and 0.015-0.40 mg·L-1 for chlorantraniliprole and flubendiamide,with correlation coefficients not less than 0.998.The detection limits of flonicamid,chlorantraniliprole,flubendiamide and tolfenpyrad were 0.005,0.002,0.000 5,0.000 8 mg·kg-1,respectively. The recoveries for the four pesticides in vegetables and fruits were between 80% and 95% at fortified levels of 0.05-5.0 mg·kg-1 for tolfenpyrad and flonicamid,and 0.01-1.0 mg·kg-1 for chlorantraniliprole and flubendiamide.The intra assay and inter assay RSDs of four compounds were in the ranges of 2.0%-6.1% and 3.3%-7.6%,respectively.The results indicated that the method was suitable for the determination of tolfenpyrad,flonicamid,chlorantraniliprole and flubendiamide in vegetables and fruits sample.关键词：tolfenpyrad;flonicamid;chlorantraniliprole;flubendiamide;liquid chromatography-tandem mass spectrometry;residue
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发布时间： - 摘要：A high performance liquid chromatographic method was established for the simultaneous detection of contents of sixteen food additives,including acesulfame K,saccharin sodium,benzoic acid,sorbic acid,dehydroacetic acid,new red,fancy red,tartrazine,amaranth,carmine,sunset yellow,brilliant blue,erythrosine,methyl p hydroxybenzoate,ethyl p hydroxybenzoate and propyl p hydroxybenzoate,in preserved fruits.The sixteen food additives were separated on an Athena C18 wp column （4.6 mm×250 mm,5 μm） by gradient elution using methanol-0.02 mol/L ammonium acetate as mobile phase,and analyzed with a diode array detector. The calibration curves were linear in the concentration range of 1-100 mg/L,with correlation coefficient not less than 0.999 88 and LOD of 0.016-0.45 mg/L.The relative standard deviations（n=10） of the method was between 0.14% and 1.5%,and the spiked recoveries of sixteen compounds in preserved fruits ranged from 76% to 106%.The method was suitable for the analysis of food additives contents in preserved fruits with good accuracy and precision.关键词：high performance liquid chromatography;additive;preserved fruit
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发布时间： - 摘要：A liquid chromatography-tandem mass spectrometric method was developed for the simultaneous determination of seven triazole alcohol fungicides,including cyproconazole,triadimenol,flutriafol,tebuconazole,hexaconazole,diniconazole and bitertanol,in vegetables.Seven triazole alcohol fungicides were extracted from samples with methanol,and cleaned up by dispersive solid phase extraction.The separation of target compound was carried out on a C8 column using methanol-0.05% formic acid as mobile phase.The quantitative analysis of seven triazole alcohol fungicides were performed by tandem mass spectrometry with the external standard method.The results indicated that the calibration curves for the seven triazole alcohols were linear in the range of 1.0-20 μg/L with correlation coefficients more than 0.997,and the quantitation limits for the triazole alcohols were 10 μg/kg.The spiked recoveries for seven triazole alcohol fungicides from pea,tomato and qinggengcai matrices were in the range of 70%-100% with relative standard deviations not more than 10.7%.This method was simple and accurate,and was suitable for the simultaneous determination of seven triazole alcohol fungicides in vegetables.关键词：vegetable;triazole alcohol;dispersive solid phase extraction;liquid chromatography-tandem mass spectrometry
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发布时间： - 摘要：A LC-AFS method was developed for the determination of thimerosal residues in foods of animal origin.The analyte in sample was extracted with the acidic and basic extraction solutions,and separated by liquid chromatography.Thimerosal was mixed with oxidizing reagent and air,then exposed to UV light,and oxidized to inorganic mercury.After hydride generation reaction,the atomized mercury could be determined by atomic fluorescence spectrometry（AFS）.Sample preparation,mobile phase,oxidizing reagent and operating conditions of AFS were optimized.Under the optimal conditions,the calibration curve for thimerosal was linear over the concentration range of 0-20 μg/L with a correlation coefficient of 0.999 4.The detection limit was 0.4 μg/L.The average recoveries of thimerosal from five samples spiked at three levels of 10.0,20.0,40.0 μg/kg were in the range of 71%-83% with RSDs of 1.6%-4.5%.The method was suitable for the determination of thimerosal residues in foods of animal origin.关键词：LC-AFS;food of animal origin;thimerosal;residues
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发布时间： - 摘要：A high performance liquid chromatography-tandem mass spectrometric （HPLC-MS/MS） method was developed for the determination of benzoic acid and sorbic acid in seasoning. The samples of seasoning were acidified by hydrochloric acid and extracted by diethyl ether for several times. The extract was washed with acidic sodium chloride,then evaporated to dryness.The residue was filtrated with membrane and reserved for analysis after dissolved in 1 mL 90% 0.2 mmol/L NH4OAc（pH 5.0）acetonitrile solution.The conditions of extraction and purification were optimized.The analyte was identified under negative electrospray ionization（ESI-） mode and analyzed quantitatively by the external standard method under the single reaction monitoring（SRM） mode.The calibration curve showed a good linearity in the concentration range of 0.5-5 mg/L with correlation coefficients （r2） more than 0.995. The limits of detection（LODs） of benzoic acid and sorbic acid both were 0.1 mg/kg and their limits of quantitation（LOQs） were 0.4 mg/kg and 0.5 mg/kg,respectively.The recoveries of benzoic acid and sorbic acid were in the ranges of 84%-98% and 82%-96%，respectively, with RSDs less than 3%. Actual test results also showed that the method was simple, sensitive and accurate, and was suitable for the trace determination of benzoic acid and sorbic acid residue in complex matrices.关键词：HPLC-MS/MS;trace detection;benzoic acid;sorbic acid;seasoning
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发布时间： - 摘要：A high performance liquid chromatographic method was developed for the simultaneous determination of 10 synthetic colours such as indigotin，new red，brilliant blue，tatrazine，sunset yellow，amaranth，ponceau 4R，carmoisine，allura red and erythrosine in ice-cream. The optimal extraction conditions and HPLC chromatographic conditions were confirmed by investigating the extracting solvent，mobile phase type and maximum absorption wavelength. The sample was extracted with methanol water solution，and the extract diluted with water was separated on a Symmetry C18(25 cm×4.6 mm×5 μm）column using methanol - 20 mmol/L ammonium acetate as mobile phase by gradient elution. The target compounds were confirmed by diode array detection and quantified by the external standard method. Under the optimal conditions，the calibration curves of 10 synthetic colours showed good linearities in the range of 0.5-10.0 mg/L，with their correlative coefficients more than 0.997. The mean recoveries at 3 spiked levels of 2，10，50 mg/kg ranged from 76% to 108% with RSDs of 0.56%-2.8%. The detection limits were in the range of 0.2-1.0 mg/kg. The method was simple，rapid，sensitive and accurate，and was suitable for the determination of 10 synthetic colours in ice-cream.关键词：Ice-cream;synthetic colour;high performance liquid chromatography
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发布时间： - 摘要：A ionexchange chromatographic method with conductivity detection was developed for the determination of acetylcholine（Ach）residue in dairy products and royal jelly. The sample was extracted with ultra-pure water by ultrasonic,and then determined by ion chromatography. The quantification was performed by the external standard,using IonPac CS17(250 mm×4.0 mm i.d.) column as analytical column,and methylsulfonic acid(MSA)as mobile phase at a flow rate of 1.0 mL/min. The column temperature was set at 30 ℃,and the detection cell temperature was set at 35 ℃. The calibration curve was linear between the peak area and the Ach concentration in the range of 0.02-2.0 mg/L with a correlation coefficient of 0.999 9. The limit of detection of Ach was 0.3 mg/kg in milk,yogurt and royal jelly matrices,and 1.0 mg/kg in milk powder matrix.The average recoveries of Ach from spiked dairy products and royal jelly sample ranged from 90% to 98% with RSDs of 3.0%-6.2%.关键词：ion chromatography;dairy product;royal jelly;acetylcholine
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发布时间： -
Separation and Determination of Two Alkaloids in Sophora Flavescens by Electrostacking-Sweeping-MEKC
摘要：A new method of electrostacking-sweeping micellar electrokinetic chromatography was developed for the simultaneous determination of two alkaloids,matrine and sophoridine,in sophora flavescens.The determination conditions including pH value,concentration of NaH2PO4 and CTAB,injection time and voltage were optimized.A best separation of two alkaloids was obtained on an uncoated fused silica capillary column(60 cm×50 μm,effective length 47 cm) by using a buffer of 20 mmol/L NaH2PO4-0.8 mmol/L CTAB-100 mmol/L Tris（containing 10% isopropanol） at pH 8.9 and a constant temperature of 25 ℃.The UV detection wavelength was set at 211 nm.The applied voltage,separation voltage and injection time were -10 kV,-20 kV and 480 s,respectively.Under the optimal conditions,the calibration curves were linear in the range of 46-736 μg/L for matrine and 50-792 μg/L for sophoridine with their detection limits(S/N=3) of 2.41 μg/L and 1.11 μg/L,respectively.The spiked recoveries were in the ranges of 93%-109% and 89%-103%,respectively,with RSDs less than 5%.Compared with the sweeping-MEKC method, the electrostacking-sweeping-MEKC method raised the sensitivity by two orders of magnitude.The method showed high separation efficiency and good sensitivity,and was applied in the simultaneous separation and determination of two alkaloids in sophora flavescens with satisfactory results.关键词：micellar electrokinetic chromatography;electrostacking;sweeping;matrine;sophoridine- 2196
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发布时间： - 摘要：A derivatization method for the determination of glyphosate was developed by using o nitrobenzenesulfonyl chloride as derivatization reagent.The optimized conditions of derivatization were as follows:reaction temperature:25 ℃，reaction time:10 min，buffer solution:0.25 mol/L borate buffer（pH 9.0），the molar ratio of glyphosate to o-nitrobenzenesulfonyl:1∶5.The optimal chromatographic conditions were as follows：Lichrospher C18 column（5 μm，4.6 mm×250 mm），detection wavelength:230 nm，flow rate:1.0 mL/min，mobile phase:methanol-pH 5.5 0.05 mol·L-1phosphate buffer(20∶80)．Under the optimal conditions，the calibration curve for glyphosate was linear in the range of 0.05-1.0 g·L-1 with a correlation coefficient （r2）of 0.999 3.The limit of detection was 6.25 mg·L-1.The method was simple，rapid and reliable，and was suitable for the determination of glyphosate in general laboratory.关键词：o-nitrobenzenesulfonyl chloride;derivatization;glyphosate;RP-HPLC
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发布时间： - 摘要：A capillary electrophoresis method coupled with amperometric detection（CE/AD） was developed for the determination of echinacoside in Cistanche deserticola Y.C.Ma.Effects of types and pH values of running buffer, detection potential,applied voltage and sampling time on separation efficiency were investigated.The optimized conditions were as follows:running buffer:15 mmol/L Na2B4O7 buffer（pH 9.5）,separation voltage:25 kV,detection potential:0.6 V.Under the optimal conditions,a good linearity was obtained between peak area and mass concentration of echinacoside in the range of 0.5-50.0 mg/L with a correlation coefficient of 0.999 4.The detection limit（S/N=3） was 0.1 mg/L and the spiked recoveries ranged from 98% to 102%.The method is simple,rapid and accurate,and can be applied to control the content of echinacoside in Cistanche deserticola Y.C.Ma.关键词：capillary electrophoresis;echinacoside;amperometric detection
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发布时间： - 摘要：Three similar layered perovskite-type organic-inorganic hybrids were synthesized with selecting CuCl2 as the main inorganic component and by altering the organic component via liquid phase reaction.The inorganic component,organic component and crystalloid structure of three hybrids were characterized and analyzed by scanning electron microscope(SEM),X-ray diffraction(XRD) and FT-IR spectra.The experimental results indicated that the layered structures displayed more clearly when the organic components were alkyl amine rather than aniline.The formation of layered structure was probably related with the length of carbon chain and the structure of benzene ring.Since the interaction between the organic amine and inorganic octahedral truss (［CuCl6］4-) was the van der Waals force(mainly expressed as the hydrogen bonding H—N……Cl),the structure of the organic components played an important role in the formation of layer structured perovskite-type hybrids.According to Bragg’s equation and an approximative method,the distance of the adjacent layered perovskites(d) of three compounds with cations of propylammonium,butylammonium and phenylammonium were calculated to be 12.31,15.39,14.82?,respectively.关键词：CuCl2;organic component;layered perovskite-type;preparation;characterization
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发布时间： - 摘要：A high-performance liquid chromatographic（HPLC）method was established for the separation of various phenols.The extraction efficiency of phenols from camellia oil by the liquid-liquid extraction（LLE）was compared with that by the solid-phase extraction（SPE）method,and the experimental conditions,e.g.mobile phase types,detected wavelength and injection amount of samples were optimized.Under the optimal conditions,all 23 phenols were successfully separated in 60 min.Good linear relationships were obtained in the concentration range of 0.059-9.115 μg/g for 23 phenols,with their correlation coefficients of 0.977 6-1.000 0.The detection limits were in the range of 0.041-0.379 μg/g.The relative standard deviations were between 0.7% and 10.1%.The average recoveries of 23 phenols in camellia oil were between 72% and 101%.The proposed method was applied in the determination of phenols in camellia oil sample,and nine phenolics,including hydroxytyrosol,protocatechuic acid,catechins,p-hydroxybenzoic acid,chlorogenic acid,vanillic acid,catechin gallic acid,p-coumaric acid and ferulic acid,were identified with their contents of 1.178,2.749,1.714,1.287,0.223,0.363,0.219,0.363,0.097 μg/g,respectively.The results indicated that the method was accurate and reliable,and was suitable for the analysis of different phenols in various camellia oils.关键词：camellia oil;phenols;high-performance liquid chromatography（HPLC）;solid-phase extraction（SPE）
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发布时间： - 摘要：A high performance liquid chromatography （HPLC） coupled with photodiode array detector （PDAD） method was developed for the determination of content of hydroquinone, phenol, salicylic acid, 2-phenoxyethanol, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, dichlorophen and triclosan in cosmetics sample. The restricted substances were extracted with acetonitrile in sonic bathing for 10 min. The chromatographic separation was completed with a column of Lichrosorp RP-18 （250 mm×4.6 mm, 5 μm） using methanol-acetonitrile- ammonium acetate （pH 4.0） as mobile phase. The quantification was carried out by the external standard method. The calibration curves of 10 restricted substances were linear in the range of 0.01-0.1 g/L. The recoveries at three spiked levels of 50, 100,200 mg/kg ranged from 80% to 113%. The relative standard deviations（RSD, n=7） ranged from 2.2% to 10.0% and the quantitation limits were in the range of 10- 50 mg/kg. The method was rapid, easy, accurate and sensitive, and could meet the detection requirements for domestic and foreign limited substances in cosmetics.关键词：HPLC;photodiode array detector;cosmetics;hydroquinone;phenol;triclosan;restricted substances;determination
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发布时间： - 摘要：Monolithic columns have been employed in low pressure,fast and high efficient separation,for their many excellent characteristics.When applied to ion chromatography field,monolithic columns can achieve more effective analysis than traditional columns.Therefore,the method of ion chromatography based on monolithic columns attracts increasing interests.In this paper,the sorts of ion chromatography,classification of monolithic stationary phases,preparation ways of monolithic columns,performances and features of monolithic columns were introduced.The application of conventional monolithic columns in ion chromatography and the utilization of capillary monolithic columns in capillary ion chromatography were summarized according to the different assortments and properties of monolithic columns and ion chromatography,which included silica-based monolithic stationary phase and organic polymer-based monolithic stationary phase.The development of ion chromatography based on monolithic columns in the future was reviewed and prospected.关键词：ion chromatography;monolithic column;review
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