最新刊期
卷 34 ， 期 4 ， 2015
- 摘要：A graphene/polydimethylsilane（graphene/PDMS） fiber assisted headspace solid-phase microextraction combined with gas chromatographic method was developed for the determination of six pyrethroid pesticide residues in environmental water and juice samples.This fiber exhibited a higher adsorption affinity toward pyrethroid pesticides than commercial polydimethylsilane（PDMS） and polypropylene（PA） fibers.Several parameters affecting the extraction efficiency for six pyrethroid pesticides，including extraction temperature，ionic strength，extraction time and desorption time，were optimized in sequential order using the graghene/PDMS fiber.The analytical evaluation parameters for six pyrethroid pesticides were studied under the optimized conditions.This method showed wide linearities（0.02-5 μg/L for allethrin and bifenthrin,0.1-20 μg/L for fenpropathrin，cypermethrin and fenvalerate,0.2-20 μg/L for deltamethrin），low detection limits（6.8-58.2 ng/L），low quantitation limits（18.2-154.9 ng/L） and high correlation coefficients（r2>0.99）.The relative standard deviations（RSD） for five replicate extractions were not more than 9.2% using one fiber，and the repeatability of fiber-to-fiber were in the range of 6.7%-10.8%.The method was applied in the simultaneous analysis of six pyrethroid pesticide residues in environmental water and juice samples.The recoveries for river water，fishpond water，apple juice and orange juice were in the range of 81.6%-92.9%，82.3%-96.1%，78.2%-92.8%and 79.9%-91.7%，respectively.This method was sensitive and simple，and could meet the actual requirement for the analysis of trace analytes in environmental water and concentrated fruit juice samples.关键词：graphene/polydimethylsilane;headspace solid-phase microextraction;pyrethroid pesticides;water sample;juice sample
- 2133
- |
- 496
- |
- 5
发布时间：2023-05-18 - 摘要：A method of high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry（HPLC-Q/Orbitrap MS） was developed to determine 4-methylimidazole（4-MI） and 2-methylimidazole（2-MI） in soy sauce.Samples were diluted with deionized water,and then purified with a MCX solid phase extraction column.After eluted with 5% ammoniated methanol,the eluent was evaporated to dryness at 45 ℃ under nitrogen.The residue was dissolved with a mixture of acetonitrile and water in specific proportion through a vortex mixing.The obtained mixture was then filtered through a polytetrafluoroethylene（PTFE） membrane with pore size of 0.45 μm.The analytes were separated on an Agilent HILIC Plus（2.1 mm×100 mm,3.5 μm） column by isocratic elution with acetonitrile -5.0 mmol/L ammonium acetate（80∶20，by volume） as mobile phase.Full scan experiments were performed over the range of m/z 50-100 in positive mode to determine the accurate mass of analytes.The parent ion was used for quantitation based on the external standard.Under the optimal conditions,4-MI and 2-MI were well separated.The detection limits for 4-MI and 2-MI were 2.5 mg/kg.Good linearities were obtained in the range of 25-500 ng/mL with their correlation coefficients higher than 0.99.The average recoveries at three spiked levels were in the range of 78.3%-95.7% with relative standard deviations（RSDs） not more than 9.4%.The proposed method was simple and sensitive,and could meet the requirements for the determination of 4-MI and 2-MI in all kinds of soy sauce,contribute to regulate the production of soy sauce and the addition of caramel colours.关键词：4-methylimidazole(4-MI);2-methylimidazole(2-MI);high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry（HPLC-Q/Orbitrap MS）;soy sauce;caramel colours
- 2122
- |
- 507
- |
- 4
发布时间：2023-05-18 - 摘要：An ultra-high performance liquid chromatography-tandem quadrupole mass spectrometric（UPLC-MS/MS） method was developed for screening of 20 kinds of hormones residues in beef and milk products.The homogeneous samples（beef with enzymatic treatment，milk without enzymatic treatment） were purified with HLB column，then analyzed on a BEH C18 column with methanol-0.1% formic acid as mobile phase by gradient elution in positive ion mode and multiple reaction monitoring mode.4 kinds of hormones were quantified by external standard method，and 16 kinds of hormones were quantified by internal standard method.The calibration curves were linear in the range of 0.10-10 μg/kg with correlation coefficients not less than 0.995 1.The limits of detection（LOD） and limits of quantitation（LOQ ） were 0.10-0.30 μg/kg and 0.40-1.00 μg/kg，respectively.Recoveries of the target compounds at three added levels were between 70.5% and 97.5% with relative standard deviations of 1.3%-12.9%.When 4 kinds of hormones were quantified by external standard method，blank matrix matched calibration curves were used.The method is simple，rapid and sensitive,and is suitable for the rapid analysis of food safety incidents.关键词：ultra performance liquid chromatography-tandem mass spectrometry;hormones;screening;beef;milk
- 2121
- |
- 510
- |
- 4
发布时间：2023-05-18 - 摘要：In the paper，adenosine complementary aptamer strand（S1） and carboxylic acid terminated DNA（S2） were firstly modified on the gold nanoparticles（GNPs） surface through Au-S bonds.With the help of the amidation reaction of toluidine blue（TB） and S2，TB was labeled on the surface of gold nanoparticles for the preparation of TB labeled DNA probe TB-S2-GNPs-S1.Then a layer of gold nanoparticles was electro-deposited on the glass carbon electrode surface，which was used as the immobilization matrix for adenosine aptamer with terminal mercapto group.Subsequently，bovine serum albumin（BSA） as a blocking agent was used to eliminate non-specific adsorption.TB-S2-GNPs-S1 was immobilized on the electrode surface through the hybridization of S1 and the adenosine aptamer.An aptamer biosensor was constructed with toluidine blue as the electrochemical redox probe.The synthesized gold nanoparticles and TB-S2-GNPs-S1 composites were characterized by UV-Vis spectroscopy and scanning electron microscopy.The electrode assembly process was monitored by cyclic voltammetry and electrochemical impedance spectroscopy.The sensor’s performance was studied by differential pulse voltammetry and electrochemical impedance spectroscopy.The sensor showed a linear relationship to adenosine from 1.0×10-4 ng/mL to 100.0 ng/mL，with a correlation coefficient（r） of 0.994 and a detection limit（S/N=3） of 64.7 fg/mL.关键词：adenosine;aptasensor;toluidine blue;gold nanoparticles
- 2135
- |
- 397
- |
- 5
发布时间：2023-05-18 - 摘要：The three-dimensionally ordered macroporous gold-nanoparticle-doped titanium dioxide（3DOM GTD） film was modified on the indium-tin oxide（ITO） electrode surface and cytochrome c（Cyt c） was successfully immobilized on the 3DOM GTD/ITO.A kind of Cyt c enzyme biosensor（Cyt c/3DOM GTD/ITO） was prepared.The properties of 3DOM GTD film were characterized by transmission electron microscopy（TEM） and scanning electron microscopy（SEM）.UV-Vis spectrum indicated that the Cyt c immobilized on the film retained its biological activity and the secondary structure of Cyt c was not destroyed.The direct electrochemistry（DET） of Cyt c on the surface of the modified electrode and its electric catalytic behavior to H2O2 were also studied.The results indicated that Cyt c showed an obviously direct electrochemistry response.The peak currents were linear with scan rates,which indicated that the electrochemical behavior of Cyt c/3DOM GTD/ITO electrode was a surface-controlled process.The Cyt c/3DOM GTD/ITO electrode showed a good catalytic performance to hydrogen peroxide,and a wide linear range of 3.0×10-7-1.7×10-5 mol/L was obtained with a detection limit（S/N=3） of 3.6×10-8 mol/L and a rapid response of 5 s.The electrode showed a good reproducibility and stability.关键词：three-dimensionally ordered macroporous structure（3DOM GTD）;cytochrome c（Cyt c）;direct electrochemistry;hydrogen peroxide
- 1998
- |
- 401
- |
- 2
发布时间：2023-05-18 - 摘要：A rapid,sensitive and highly precise method was developed for the direct and continuous determination of the inhibitory effect on mushroom tyrosinase activity of natural products.Based on ο-quinone,L-DOPA was catalyzed by tyrosinase into the corresponding brown product,which has the biggest absorption at 475 nm.The tyrosinase inhibitor can reduce the enzymatic reaction rate,and then make the OD475 lower into a negative peak.The RSD of injection 10 times on the IC50 of kojic acid is 0.036%,and the precision of the approach was improved more than 10 times as compared with the spectrophotometric method and microtitration assay.By using the sample for further verification,the results showed that caffeic acid has a potent activating effect on diphenolase activities of tyrosinase,its concentration leading to 50% activation rate（IC50 ） is 0.170 mmol/L.The water-soluble extraction from Lavandula angustifolia has a potent inhibitory effect on diphenolase activities of tyrosinase,its IC50 value is 0.96 mg/mL.Compared with the spectrophotometric method and microtitration assay,flow injection-spectrophotometric approach has a higher precision,better repeatability and is suitable for the determination of influence on tyrosinase activity from natural products.关键词：flow injection-spectrophotometric approach;natural products;tyrosinase activity
- 2062
- |
- 484
- |
- 0
发布时间：2023-05-18 - 摘要：A high performance liquid chromatography/quadrupole time-of-flight mass spectrometric（HPLC/QTOF-MS） method was adopted to identify the related substances in α-ketophenylalanine calcium(KTP) and a reversed-phase high performance liquid chromatographic（RP/HPLC） method was established for the quantitative determination of its related substances.A C18 column（4.6 mm×150 mm,5 μm） was adopted for quantitative analysis of related substances,with 20 mmol?L-1 potassium dihydrogen phosphate（pH value was adjusted to 3.30 with phosphoric acid） -acetonitrile（85∶15） as mobile phase at a flow rate of 1 mL?min-1,and the detection wavelength was set at 205 nm.The column temperature was 30 ℃ and the injection volume was 10 μL.Two impurities was confirmed as benzoic acid and phenylacetic acid.Under the optimized chromatographic conditions,the calibration curves of the analytes showed good linearities within the mass concentrations of 0.64-5.76 μg?mL-1（r=0.999 6） for benzoic acid and 0.65-5.82 μg?mL-1（r=0999 5） for phenylacetic acid.The detection limits for benzoic acid and phenylacetic acid were 1.3 ng and 1.6 ng,respectively.The average recoveries（n=9） were 99.6% and 99.0% with relative standard deviations（RSDs） of 1.6% and 1.5%,respectively.The results indicated that HPLC/QTOF-MS method could be effectively used to perform the identifications of related substances in α-ketophenylalanine calcium.The method for quantitative determination of related substances was sensitive,reproducible,accurate and reliable.It could be applied in the analysis of the related substances and the quality control of α-ketophenylalanine calcium in raw material.关键词：α-ketophenylalanine calcium(KTP);related substances;high performance liquid chromatography/quadrupole time-of-flight mass spectrometry;reversed-phase high performance liquid chromatography
- 2082
- |
- 440
- |
- 0
发布时间：2023-05-18 - 摘要：A method was developed for the determination of 46 pesticides in sulfur-containing vegetables(e.g.scallion,ginger,Chinese chives and garlic） using solid-phase extraction（SPE） and gas chromatography-triple quadrupole mass spectrometry（GC-MS/MS）.The extraction solvent,solid-phase extraction column and elution solution were optimized.The pesticides were extracted with acetonitrile containing 1% acetic acid,and then cleaned up on a Carbon/NH2 SPE column.The extracts were determined by GC-MS/MS under multiple reaction monitoring（MRM） mode with the external standard method.The calibration curves of 46 pecitides were linear in the range of 0.05-1.00 mg/L with limits of detection（LOD） of 0.001-0.003 mg/kg.The recoveries of all pesticides at the spiked levels of 0.01,0.05,0.10 mg/kg in matrices were in the range of 60%-125%,with relative standard deviations（RSDs） not more than 17.3%.The method covers many kinds of pesticides（e.g.organophosphates,organochlorines and pyrethroids）,with high sensitivity but low background.Therefore,it is suitable for the analysis of pesticide residues in sulfur-containing vegetables.关键词：gas chromatography-triple quadrupole mass spectrometry（GC-MS/MS）;solid-phase extraction（SPE）;sulfur containing vegetables;pesticides
- 2249
- |
- 493
- |
- 13
发布时间：2023-05-18 - 摘要：In this paper，alkylphenols（APs） were separated by micellar electrokinetic chromatography(MEKC) and reversed electrode polarity stacking mode（REPSM） was developed for the on-line sample stacking of these compounds.MEKC coupled with REPSM increased 20-285 times of the sensitivity for osBP，TBBPA，BPA，OP and NP compared to the conventional MEKC.The separation conditions in the MEKC method were studied，and many factors affecting the sample stacking process were investigated in detail.Additionally，sample injection as large as 41.37 kPa×60 s was applied in REPSM-MEKC.The linear relationship and reproducibility were also examined.Under the optimum conditions，the detection limits（S/N=3） of APs were in the range of 0.027-0.64 μmol/L.The method has been successfully applied in the detection of APs in food-packing bags with recoveries of 86.0%-103%.关键词：micellar electrokinetic chromatography;reversed electrode polarity stacking mode;alkylphenols
- 1940
- |
- 410
- |
- 3
发布时间：2023-05-18 - 摘要：The quasi-ternary phase diagrams for microemulsion systems containing sodium dodecyl sulfate（SDS）,n-butanol,oil phase（n-octanol,n-octane,n-heptane,n-hexane） and water were plotted by the titration and electrical conductivity.Effects of oil type,mass proportion of surfactant and co-surfactant upon the forming of O/W microemulsion were investigated in terms of the region for O/W microemulsion in the phase diagram.Physical and chemical parameters including electrical conductivity,interfacial tension and viscosity were used to elucidate the phase behaviors and characteristics of microemulsion systems.According to the microemulsion phase diagram,the chromatographic conditions were optimized.A rapid and robust separation method was developed and validated for the determination of Amoxicillin-Sulbactam Pivoxil tablets.Good suitability and separation selectivity of HPLC were obtained.关键词：microemulsion liquid chromatography;quasi-ternary phase diagrams;sodium dodecyl sulfate（SDS）;Amoxicillin-Sulbactam Pivoxil tablets
- 1966
- |
- 588
- |
- 1
发布时间：2023-05-18 - 摘要：environmental water by liquid chromatography-mass spectrometry（LC-MS） coupled with ultrasonic assisted extraction with ionic liquid.An ionic liquid,1-butyl-3-methylimidazolium hexafluorophosphate（［C4mim］［PF6］）,was used as extraction solvent to extract PCP in water samples.The extraction parameters,such as sample volume,temperature,ultrasonic extraction time,inorganic salt concentration and solution pH value were investigated.The chromatographic separation was performed on a XDB C18（150 mm×2.1 mm,5 μm） column with a mobile phase of methanol-2 mmol/L ammonium acetate solution（70∶30）.Detection was carried out by LC-MS using a negative electrospray ionization interface under the selected ion monitoring（SIM） mode.The calibration curve was linear within the range of 0.005-1.0 μg?L-1 with a correlation coefficient of 0.999 2.The limit of quantitation（LOQ） was 0.005 μg?L-1.The extraction recoveries were between 91.0% and 97.0%,and the intra-day RSDs were between 1.1% and 5.4%,and the inter-day RSDs were between 3.8% and 8.3%.The developed method was simple,accurate and specific,and could be used for the determination of trace PCP in environmental water.关键词：ultrasound-assisted extraction;liquid-liquid microextraction;ionic liquid;water;pentachlorophenol（PCP）;liquid chromatography coupled with mass spectrometry（LC-MS）
- 2121
- |
- 479
- |
- 7
发布时间：2023-05-18 - 摘要：A liquid chromatography-tandem mass spectrometric（LC-MS/MS） method was developed for the simultaneous determination of four nipagin esters,including methylparaben,ethylparaben,propylparaben and butylparaben in aquatic products samples（Sargassum fusiforme,porphyra,hairtail,yellow croaker）.The samples were extracted by ultraphonic extraction with methanol.Extracting solution was filtered,then cleaned up with MCX solid phase extraction.The analysis was performed on an Agilent ZOBRAX C18 column（2.1 mm×150 mm,5 μm） using a gradient elution program with mobile phase of 0.1% acetic acid and acetonitrile.The analytes were determined by an electrospray ionization tandem mass spectrometry in multiple reaction monitoring（MRM） mode,and quantified by internal standard method.The results indicated that a good separation of four compounds was obtained in 7 min.The calibration curves for four nipagin esters were linear in the range of 5.0-100.0 ng?mL-1 with correlation coefficients not less than 0.999 2,and the limits of quantitation（LOQs） were all 10.0 μg?kg-1.The average recoveries at three spiked levels ranged from 75%-96% with RSDs not more than 7.1%.This method shows the advantages of simplicity,accuracy and sensitivity,and is suitable for the analysis of four nipagin esters in aquatic product samples.关键词：aquatic products;nipagin esters;solid phase extraction;liquid chromatography-tandem mass spectrometry(LC-MS/MS)
- 2037
- |
- 436
- |
- 2
发布时间：2023-05-18 - 摘要：The star anise oil was pyrolyzed under helium atmospheres at 300,400,500,600,700,800 ℃,respectively,and the pyrolysates were identified by on-line pyrolysis/gas chromatography-mass spectrometry（Py/GC-MS）.The relative percentage compositions of volatile components were established,and the effects of pyrolyzed temperatures on amounts of volatile components formed during the pyrolyzed procedure were analyzed.Meanwhile,the relationship between the structures of perfume compositions and amounts of flavor compounds was speculated and accounted based on the theory of the structures and property of organic compounds.The results showed that:star anise oil consists of 13 constituents,and trans-anethole aucounts for the highest percentage（94.848%） among all the constituents.28 components were identified in the pyrolysates;star anise oil transferred almost intactly at lower temperature（300-500 ℃）.Some aromatic flavors,xylene and ethylbenzene etc.were produced with the rise of temperature（600-800 ℃）.Trans-anethole is the major flavor component,presenting the highest transfer ratio at 500 ℃.The results could provide a scientific reference for the safe application of star anise oil in tobacco industry.关键词：Py/GC-MS;star anise oil;transfer ratio
- 2087
- |
- 404
- |
- 1
发布时间：2023-05-18 - 摘要：A gunshot residue（GSR） analysis method by mapping technique of micro-X-ray fluorescence（μ-XRF） spectrometer was established,by optimizing the gunshot sample collecting technique,and examing the mapping images of relating elements（Cl，K，S，Sb，Sn，Ba，Pb，Hg，As，Fe，Cu，Zn,Ti,Ca,Rh） in PU clothing which was shot perpendicularly with 64 pistol at different distances（0，2，5，10，15，20，25，30，35，40，45，50，60，80，100，120，140，170，200，300，500，1 000 cm）.Furthermore,the model of GSR characteristic elemental distribution related to shooting distance was built,and the unitary quantitative data were obtained too.The method could be used to judge the gunshot range and offer the evidences for case investigation and justice.关键词：64 pistol;shooting distance;micro-X-ray fluorescence spectrometer（μ-XRF）;mapping technique;elemental distribution
- 2279
- |
- 411
- |
- 2
发布时间：2023-05-18 - 摘要：An indirect competitive enzyme-linked aptamer assay（ic-ELAA） was developed for monitoring oxytetracycline（OTC） in complex food matrix.Various factors such as OTC-BSA concentration,aptamer concentration,avidin-HRP concentration,coating buffer,blocking agent,and binding buffer were evaluated for the performance of ELAA.The optimized ELAA showed a good sensitivity（IC50 of 6.3 ng/mL） and a wide linear range（0.5-50 ng/mL） for OTC.There was no obvious cross reactivity（CR） with most of the tetracyclines pesticides.Recoveries of OTC in food samples,including milk,milk powder,chicken,fish and honey,ranged from 62.1% to 102% with relative standard deviations（RSDs） less than 15%.In addition,the developed ELAA showed a good correlation with the high performance liquid chromatographic method（r2=0.979）.The results indicated that the developed method was a simple,sensitive,accurate and cost-effective approach for the screening of OTC in food samples.关键词：oxytetracycline;aptamer;enzyme-linked aptamer assay（ELAA）;food
- 2176
- |
- 447
- |
- 1
发布时间：2023-05-18 - 摘要：A novel method for the detection of streptomycin（SM） residue in cucumber was developed based on the enhancement of the fluorescence intensity of CdTe quantum dots（QDs） in the presence of SM.The factors that influence the detection of SM were investigated,and the optimum conditions were investigated.Under the optimum conditions,a good linear relationship was found between relative fluorescence intensity of the system and concentration of streptomycin in the range of 5.0×10-12-1.0×10-10 mol/L with a correlation coefficient（r） of 0.999 0.The detection limit was 5.0×10-13 mol/L,and the recoveries were between 99% and 106%.With the advantages of high selectivity,low detection limit,simpleness and speediness,the proposed method was successfully applied in the detection of trace streptomycin residue in cucumber.关键词：streptomycin;antibiotic residues;CdTe quantum dots;fluorescence probe;cucumber
- 1999
- |
- 418
- |
- 9
发布时间：2023-05-18 - 摘要：Endocrine disrupting chemicals(EDCs),as a kind of exogenous substances,can block or mimic the synthesis,secretion,transport,metabolism,binding and elimination of natural hormones which are responsible for the maintenance of homeostasis,reproduction,development and action.EDCs interfere with the function of endocrine system in human and wildlife,and consequently cause adverse effects on development,reproduction,non-reproduction and immune system.Therefore,the pollution characteristics of EDCs in aquatic environment,particularly phenolic EDCs,are widely used,which have attracted a great deal of scientific and public attention worldwide.However,it is very difficult to determine phenolic EDCs in actual environment due to their low-dose and matrix complexity.In this review,analysis methods of the phenolic EDCs in water,including sample pretreatment and analysis technique,in recent years are summarized.The prospect about the analysis methods of phenolic endocrine disruptors is also discussed.关键词：phenols;environmental water;pretreatment technology;analysis methods;review
- 2039
- |
- 485
- |
- 6
发布时间：2023-05-18 - 摘要：As a low consumed,rapid,efficient technology,microchip electrophoresis which is also portable,integrated,and high-throughput,plays an important role in application of clinical analysis.In this paper,the advantages of microchip electrophoresis are introduced concisely.The latest advances of microchip electrophoresis in clinical applications are reviewed,including the developments in small molecules,amino acids,proteins,nucleic acids,as well as cells.And a newly developed method will be used in two-dimensional analysis,and a new wide channel microchip（WCC） system is established.The developments for the future are also discussed.关键词：microchip;capillary electrophoresis;wide bore electrophoresis;clinical analysis;review
- 2163
- |
- 434
- |
- 2
发布时间：2023-05-18 - 摘要：Microfluidic chip technology could be realized from sample preparation to detection of automatically and display many advantages,such as integration,miniaturization and portability.Therefore,it shows a strong development vigor in food safety testing.Currently,the microfluidic chip technology has achieved a series of important progresses in the determination of pesticides and veterinary drugs,heavy metals,food additives and food safety detection.This paper focuses on progress of microfluidic chip technique in application of analysis of food safety progress as well as the prospect of its application in food safety analysis.关键词：microfluidic chip;food safety;detection;review
- 2077
- |
- 485
- |
- 3
发布时间：2023-05-18 - 摘要：With the development and application of engineered nanoparticles（ENPs），ENPs have entered our daily life in various fields.A continually growing number of consumer products contain this nanomaterial with varying particles sizes and elemental compositions，which have been discharged increasingly into the environment becoming nano waste.For some time，concerns have been raised related to the potential toxicity of ENPs to human health for their special physicochemical property.As a result,analytical methods are urgently needed for the reliable determination of ENPs.Due to the small size，high surface to volume ratio and other properties，the states of ENPs are easily charged in certain environments，especially in impure，multi-component，heterogeneous and complex samples，which could not be directly used for instrumental analysis.For most of the analytical techniques，dilution of ENP samples is needed for minimum sample preparation.The stability of charge stabilized ENPs is especially sensitive to changes of pH value or ionic strength，and sometimes even to dilution.Thus，ENPs analysis in real sample could be challenging.This article reviews the general characterization and the use of ENPs，sample pretreatment methods and analytical techniques commonly used for their determination.The main aspect of this review covers the preparation procedures of liquid and powder samples，respectively.Moreover，various applications by direct determination or analysis after suitable digestion as well as novel approaches such as single particle inductively coupled plasma mass spectrometry（spICPMS） technique，and hyphenated techniques such as field flow fractionation（FFF） are discussed in detail.Finally，the future trends and developments in this research area are prospected．关键词：nanoparticles;pretreatment method;characterization and analytical techniques;review
- 2040
- |
- 487
- |
- 0
发布时间：2023-05-18
- Address：100 Xianlie Middle Road, Guangzhou Postal code：510070
- Tel：020-87684776,37656606 Fax：020-87684776 Email：fxcsxb@china.com
- Technical support is provided by Beijing Founder electronics co., LTD 粤ICP备12017312号-3
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0