简介：Aretentionpredictionsystem（RPS）ofsevenO-ethylN-isopropylphosphoro（thioureido）-thioatesinreversedphaseHPLCwasinvestigated.Thesystemisbasedonthesolventselectivitytriangleconcept.Threemolecularstructureparameters（hydrophobicityⅡ,substituentlengthL,andsubstituentmaximumwidthB5）wereusedtodescribethequantitativestructure-retentionrelation-ships.Withthesequantitativerelationships,theretentionbehavioursofothereighthomologsfordifferentmobilephasecompositionwerepredicted.Thepredictedvalueswereconsistentwiththemeasuredvalueswithinrelativeerrorof10%,whichmeansthatitispossibletoapplythereportedmethodtopredictretentionvaluesforqualitativepurposesfordifferentmobilephasecompositions.

简介：Atacertainhightemperature,thiscyclewillbedominantandendtherp-processtoheavierregion[2].Itprovidesanuppertemperaturelimitforrp-processalongtheprotondriplinetoproducenuclidesbeyondA=84,includingthelightpnuclidesof92;94Mo,96;94Ru.TheexistenceofZr-Nbcycleisanimportantquestioninrp-process[2].α-separationenergy(Sα)of84Moplaysanimportantroleintheformationofthiscycle.Astrongenhancementof83Nb(p,α)reactionrateisduetoaverylowSαof84Mo[1].

简介：通讯因素分析(CFA)被采用学习14个HPLC系统的选择。测试LC系统作为反向阶段被分类(RP)，离子交换(IE)和吸水的相互作用层析(HILIC)模式。HILIC列上的吸水的溶质的保留被秒顺序效果显著地除他们的吸水的性质以外影响，这被发现。硅石表面上的器官的修饰词和残余silanol组两个都参予了保留。Hypersil？氨基的列以适当条件在HILIC模式执行了分离，并且它的保留机理比(aspartamide)HILIC，柱涂渍poly组织更类似于HILIC硅石列的。

简介：Thispaperreportsthedevelopmentandvalidationofanassayforthedeterminationofacetonitrileintherecycledmobilephaseusinghighperformanceliquidchromatography(HPLC).Themethodisbasedonthattheretentioninreversed-phaseliquidchromatographyincreaseswithdecreasingconcentrationoforganicphaseinthemobilephase.Thenaturallogarithmofthecapacityratioforagivensoluteislinearlyrelatedtothevolumefractionoftheorganicmodifierinthemobilephase.Fordimethylphthalateanddiethylphthalate,thelinearityrangeis30%―60%,andforbiphenylandterphenyl,therangeis60%―95%.Precisionvalues(RSD)wereboth<1%andtheaccuracy(RE)wasintherangeof±1%.Theassaywassuccessfullyappliedtothedeterminationofacetonitrileconcentrationofrecycledmobilephaseafterthedistillationofthecolumneluentinourlaboratory.

简介：TheroleplayedbyDNAinmolecularbiologyisclearlyrecognizedtobevitaltolifeonthisplanet.8-oxo-7,8-dihydro-2deoxyguanosine(=8-OHdG),isprobablythemostimportantproductof"oxidativestress”inDNA.ItsconcentrationinDNAis,infact.aquantitativeanalysisofthedegreeofDNAdamagethatanorganismhasundergone.Duetotheimportanceof8-OHdGofnucleicacidginmutagenesis,carcinogenesisandaging,numerouschemicalandbiologicalinvestigationshavebeenmadeonthissubjectinthepasttime.Kuchinoandco-workershavefoundthat8-OHdGresidueinDNAismisreadingduringtheprocessofDNAreplication.Recently,somereportshavebeenpresentedonhigh8-OHdGlevelsinpatientssufferingfromvariousdiseasessuchaschronichepatitis,Fanconisanemia,diabetesmellitusandHelicobacterpyloriinfections.Asaresult,8-OHdGisausefulmarkerforthestudyofDNAdamagearisingfromreactiveoxygenspeciesandisofgreatsignificanceforcancerresearch.The8-OHdGlevelsinDNAcanhelpunderstandthemechanismofcarcinogensandleadtomoreeffectivetreatmentsformanydifferenttypesofcancer.Forthesereasons,ananalysisof8-OHdGwithquickness,lowcostandhighaccuracyisrequired.

简介：Arapidandeffectivemethod,solidphaseextractioncoupledwithhighperformanceliquidchromatography(SPE-HPLC),wasappliedtotheseparationandanalysisofginsenosides.WatersOASISHLBwasusedforconcentratingandpurifyingsamplesandAlltimaC_(18)(53mm×7mm,3μm)chromatographycolumnwasusedforseparatingginsenosideRg_1,Re,Rb_1,Rc,Rb_2andRd.Theseginsenosideswereanalyzedwithin20mininourgradientelutionprocessandtheequilibriumtimeofthechromatographycolumncostonly5min.Moreover,therewasnoobviousbaselinedriftinourexperiment.Thismethodwasusedtoanalyzethecontentsofginsenosidesindifferentginsengproductsforqualitycontrol.Fourginsengproductswerestudied,includingtwokindsofcapsules,onekindoftabletandonekindofinjection.Theresultsshowthatthemethoddevelopedinthispaperhadgoodaccuracy,linearityandprecision.Therefore,thismethodcouldbeappliedinqualitycontrolofginsengproducts.

简介：设(M,T)是一个光滑闭流形上的对合,不动点集为F=RP(4)UP(4,2n-1),则它的每一个对合(M,T)必协边(RP(4)×RP(4),twist)和(P(4,2n),T')之一.

简介：

简介：Apartiallysubstitutedβ-cyclodextrinchiralstationaryphasewaspreparedbythereactionofphenylisocyanate.TheenantiomersofaseriesofO,O-diethyl(p-methylbenzenesulfonamido)-aryl(oralkyl)-methylphos-.phonateswerestudiedonthepreparedphenylcarbamatederivativeβ-cyclodextrinbondedphaseandacommercial(S)-(.+)-l-(l-naphthyl)ethylcarbamatederivativeβ-cyclodextrinbondedphaseonnormalphasechromato-graphiccondition.Resultsshowthatthepreparedphenylcarbamatederivativeβ-cyclodextrinbondedphasehasbetterenantiomericselectivitytotheseriesofcompounds.Achiralrecognitionmechanismwassuggestedfortheseparationofthesenovelorganicphosphorusenantiomers.

简介：建立了多反应监测法测定化妆品中α-萘酚和β-萘酚2种禁用着色剂的高效液相色谱-二级质谱联用（HPLC-MS/MS）的分析方法.针对几类美妆用品进行了样品前处理、色谱分离条件和二级质谱条件的研究.色谱条件经优化后确定：以常用的反相键合的十八烷基为固定相,以乙腈和水的二元流动相进行梯度洗脱,以配有电喷雾离子源的二级质谱为检测器等.考察了膏霜类、油状液体类和水类不同基质化妆品中两种萘酚异构体的加标回收率,标准偏差和变异系数.在0.05-10.0mg/L的范围内,2种目标物均有良好的线性关系,检测限（S/N≥10）均为0.2ng/g.6个样品的高、中、低3个标准添加水平下,回收率为81.95%-98.30%,相对标准偏差为0.0015%-0.078%,变异系数为0.83%-8.2%.样品中均未发现禁用着色剂萘酚的2种异构体.该方法可用于化妆品中α-萘酚和β-萘酚的检测.

简介：

简介：

简介：采用柱后光化学衍生-高效液相色谱法测定了4种中药材中黄曲霉毒素B1、B2、G1和G2的含量.黄曲霉毒素B1,B2,G1和G2的检出限分别为1.65×10-3,5×10-3,1.65×10-3和5×10-3ng;平均回收率为82.2%-89.6%;保留时间的相对标准偏差为：0.56%-0.61%;色谱峰面积的相对标准偏差为：0.27%-0.54%.实验结果表明,该方法灵敏度高,检出限低,重现性好,可以满足黄曲霉毒素的定性和定量分析的法规需要.

简介：AnHPLCmethodforquantitativedeterminationofadrenalinehydrochlorideinjectionandnoradrenalinebitartrateinjectionwasestablishedandvalidatedwithasubstituteforthereferencesubstance.Phenylephrinehydrochloridewasselectedasthesubstituteforthereferencesubstanceofadrenalineandnoradrenalinebitartrate.Thecorrectionfactorofphenylephrinehydrochloridewithrespecttothereferencesubstanceofadrenalineandnoradrenalinebitartratewasdeterminedunderdefinedconditions.Adrenalinehydrochlorideinjectionandnoradrenalinebitartrateinjectionwerequantifiedbyassayingphenylephrinehydrochlorideandacorrectfactor.TheresultsindicatethattheHPLCmethodwiththesubstituteforreferencesubstancewasreliableandfeasibleforquantitativedeterminationofdrugs.

简介：Fivechiralstationaryphases(CSPs)wereusedtoseparatetheenantiomersofaseriesofO,O-diethyl(p-methyl-benzenesulfonamindo)-aryl(alkyl)-methylphosphonates.Achiralrecognitionmechanismwaspresentedtoexplaintheresolutionofthesecompounds.ResultsshowthatCSPwithstrongπ-acceptor3,5-dinitrobenzoylgroupandhighsterichindrancehasthebestresolutionabilityinchiralseparationofO,O-diethyi(p-methyl-benzenesulfonamindo)-aryl(alkyl)-methylphosphonates.WhenaCSPhasjustastrongπ-acceptor3,5-dinitrobenzoylorhighsterichindranceitdoesnothavegoodchiralresolutionability.ThechiralrecognitionismoredifficultwhentheCSPhasmorethanoneasymmetriccenter.

简介：联合柱前衍生化技术，成功地用高效液相色谱法（HPLC）测定了水体中微量溴酸盐含量。通过衍生化条件的优化，方法回收率在98％-105％之间、相对标准偏差RSD小于2．0％，线性相关系数达0．9995，检测限为1．0μg／L。方法简便快速、准确可靠，能满足现有标准的检测要求。

简介：Thesynthesisandspectrophotometricpropertiesof2-(6-methyl-2-benzothiazolylazo)-5-diethylaminophenol(MBTAE),andtheuseofitasaprecolumnderivatizingreagenttoseparateCo(Ⅱ),Ni(Ⅱ),Rh(Ⅲ)andIr(Ⅳ)complexesbyHPLCarediscussed.Whenthemobilephaseconsistsofmethanol/water(90/10Ⅴ/Ⅴ),acetatebufferwithpH4.0and5×10-5mol/LEDTAsolution,thefourcomplexesCanbeseparatedwithin9minonODScolumn.Thedetectionlimits(20μLsamplesize)are0.059ppb,0.062ppb,0.053ppband0.049ppbforCo(Ⅱ),Rh(Ⅲ),Ni(Ⅱ)andlr(Ⅳ)respectivelyatasignal-to-noiseratioof3.

简介：采用HPLC—ESI—MS法建立了一种快速筛选并鉴定补骨脂甲醇提取物中抗氧化活性成分的方法，即利用Z-苯基三硝基苯肼（DPPH·）与补骨脂甲醇提取物中抗氧化活性成分反应前后色谱图中峰面积的变化来筛选出抗氧化活性物质，同时利用电喷雾质谱对这些活性组分进行结构鉴定．利用该方法从补骨脂甲醇提取物中筛选出了8个抗氧化活性组分，分别为新补骨脂异黄酮，补骨脂二氢黄酮，补骨脂异黄酮，补骨脂定，异利、骨脂查尔酮，补骨脂二氢黄酮甲醚，corylifol和补骨脂酚．这种方法较传统的筛选方法省时省力，既不容易造成微量组分

简介：采用液相色谱-蒸气发生-原子荧光光谱联用技术（HPLC-HG-AFS,以下简称LC-AFS）对水产动植物样品中无机砷进行测定。藻类中以紫菜、海带、羊栖菜为研究对象,水产动物中以贝类、鱼类、虾类为研究对象,实验中研究了流动相的种类和浓度、提取剂的种类和浓度,并通过正交实验法确定了最佳提取温度、提取时间、氧化时间。在最优的实验条件下运用等度洗脱的方式测定了样品中无机砷的含量,并对方法的有效性进行了验证,结果表明,三价砷、五价砷、一甲基砷和二甲基砷在5-100μg/L范围内线性关系良好;同时对不同海产品进行加标回收实验,结果表明,各组分的加标回收率在80%-105%。平行样品测定结果的相对标准偏差在2%-6%。说明液相色谱-原子荧光光谱联用法很好地解决了水产品中砷形态测定的问题,尤其对无机砷的测定提供了非常有效的方法。方法简便、准确、设备价格低廉,完全可用于水产动植物产品中无机砷的测定。

简介：