离子液体在色谱中的应用优秀课件.ppt

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1、离子液体在色谱中的应用第1页，本讲稿共16页 高效液相色谱法包括正相高效液相色谱法和反相高效液相色谱法。正相高效液相色谱法中流动相的极性小于固定相的极性，也就是以及性键合相为固定相（常以氨基、氰基键合相等作为固定相）。反相高效液相色谱法中流动相的极性大于固定相的极性，也就是以非极性键合相为固定相（常以十八硅烷C18、辛烷C8、甲基C1、苯基等作为固定相）。离子对试剂是由强亲水离子形成，反作用于样品分子中的中性离心子对。因此，可用于同时分离带电分子和非带电分子。一般适用所有色谱固定相，流动相含水至少达10，否则就有产生沉淀的危险（特别是在使用乙腈的情况下）。当使用长链的离子对试剂时，如十六烷基硫

2、酸铵或十二烷基硫酸钠，色谱柱将选用反相色谱柱。2第2页，本讲稿共16页 抗衡离子：在离子型聚合反应中，存在于增长链末端活性离子附近的相反电性离子。洗脱与洗脱剂：在洗脱色谱操作中，流动相携带待测组分在色谱柱内向钱移动并流出色谱柱的过程称为洗脱。所用流动相称为洗脱剂。3第3页，本讲稿共16页2.反相高效液相色谱法中离子液体作为流动相添加剂对儿茶酚胺保留值的影响3.离子交换色谱法和反相高效液相色谱法离子交换色谱法和反相高效液相色谱法分析选定的离子液体阳离子分析选定的离子液体阳离子4.1-烷基烷基3-甲基咪唑离子液体作为洗脱剂对甲基咪唑离子液体作为洗脱剂对液相色谱法分离麻黄素的影响液相色谱法分离麻黄素

3、的影响1.反相液相色谱法测定选择性室温离子液反相液相色谱法测定选择性室温离子液体阳离子体阳离子5.离子液体双水相体系，高效液相色谱法离子液体双水相体系，高效液相色谱法测定鸦片生物碱的样品前处理过程测定鸦片生物碱的样品前处理过程4第4页，本讲稿共16页6.使用四氟硼酸咪唑离子液体抑制液相色使用四氟硼酸咪唑离子液体抑制液相色谱分析中游离硅羟基的不利影响谱分析中游离硅羟基的不利影响7.离子液体在液体色谱法中减少硅羟基的离子液体在液体色谱法中减少硅羟基的相互作用相互作用 8.基于离子液体的液相微萃取基于离子液体的液相微萃取-高效液相色高效液相色谱法测定水中有机磷农药谱法测定水中有机磷农药9.液体作为高

4、效液相色谱分析的添加剂：液体作为高效液相色谱分析的添加剂：分析胺和离子液体的相互作用机制分析胺和离子液体的相互作用机制10.离子液体液液萃取离子液体液液萃取-高效液相色谱测定水中高效液相色谱测定水中酚类化合物酚类化合物5第5页，本讲稿共16页1.Reversed-phase liquid chromatographic method for the determination of selected room-temperature ionic liquid cations AbstractThe separation of selected 1-alkyl-and 1-aryl-3-meth

5、ylimidazolium-based room temperature ionic liquid cations has been performed using reversed-phase high-performance liquid chromatography with electrospray ionization mass detection.The RP-HPLC method development started with the selection of a column taking into account especially the resolution of

6、low molecular congeners of the selected group.Mobile phase composition was optimized for peak resolution,sensitivity and high reproducibility of retention values.The results of the method development were applied to the determination of exemplary ionic liquid species present in the medium used in cy

7、totoxicity studies.6第6页，本讲稿共16页2.Effect of Ionic Liquids as Mobile Phase Additives on Retention of Catecholamines in Reversed-Phase High-Performance Liquid Chromatography Abstract Ionic liquids or room temperature ionic liquids have been widely investigated as new solvents for catalysis in the past

8、several years.Because of some special properties of ionic liquids,interest of using them in different chemical processes is increasing.This work reports on the use of 1-alkyl-3-methylimidazolium salts and N-butyl-pyridinium salts as new mobile phase additives for separation of catecholamines in reve

9、rsed-phase high-performance liquid chromatography.The good separation is achieved by using these additives.Different pH values of the mobile phase,concentration of ionic liquids,and different alkyl substituents on the cations or different counterion of ionic liquids were investigated.The separation

10、mechanism involves molecular interactions between ionic liquids and catecholamines.7第7页，本讲稿共16页3.Analysis of selected ionic liquid cations by ion exchange chromatography and reversed-phase high performance liquid chromatography Abstract The chromatographic behavior of ionic liquids-homologues of 1-a

11、lkyl-3-methylimidazolium and 4-methyl-N-butyl pyridinium-has been investigated with a strong cation exchange adsorbent.In particular,the dependence of the retention properties of these solutes on mobile phase composition,pH,and buffer concentration was evaluated with the aim of optimizing and improv

12、ing the selectivity and retention of solute separation.While using the SCX stationary phase,several interactions occurred with varying strengths,depending on the mobile phase composition.Cation exchange,nonspecific hydrophobic interactions,and adsorption chromatography behavior were observed.Reverse

13、d phase chromatography occurred at low concentrations of acetonitrile,electrostatic and adsorption interactions at higher organic modifier concentrations.Elevated buffer concentrations lowered the retention factors without affecting the selectivity of ionic liquids.Obtained results were further comp

14、ared to the chromatographic behaviour of ionic liquids in the reversed phase system.All analyzed ionic liquids follow reversed-phase behavior while being separated.Much lower selectivity in the range of highly hydrophilic compounds is obtained.This suggests preferred use of ion chromatography for se

15、paration and analysis of compounds below 4 carbon atoms in the alkyl side chain.8第8页，本讲稿共16页4.Effect of 1-alkyl-3-methylimidazolium-based ionic liquids as the eluent on the separation of ephedrines by liquid chromatography AbstractThe chromatographic behavior of ephedrines(norephedrine,ephedrine,pse

16、udoephedrine and methylephedrine)on a C18 column was studied with different concentrations of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquids as the eluent at pH 3.0.The addition of ionic liquid has great effects on the separation of these basic compounds:decreasing band tailing,reducing

17、 band broadening,and improving resolution.The retention times of the analytes increase at first and then decrease with the increase in the concentration of ionic liquid.This effect may be attributed to the competition between imidazolium cations and the polar groups of the analytes for the silanol g

18、roup on the alkyl silica surface,and also to the formation of weak bilayer electronic structure on the C18 column.Several ionic liquids with different alkyl substituents on the imidazolium cations or with different counterions as the eluents were compared.9第9页，本讲稿共16页5.Ionic liquid-based aqueous two

19、-phase system,a sample pretreatment procedure prior to high-performance liquid chromatography of opium alkaloids AbstractAn ionic liquid,1-butyl-3-methylimidazolium chloride(C4mimCl)/salt aqueous two-phase systems(ATPS)was presented as a simple,rapid and effective sample pretreatment technique coupl

20、ed with high-performance liquid chromatography(HPLC)for analysis of the major opium alkaloids in Pericarpium papaveris.To find optimal conditions,the partition behaviors of codeine and papaverine in ionic liquid/salt aqueous two-phase systems were investigated.Various factors were considered systema

21、tically,and the results indicated that both the pH value and the salting-out ability of salt had great influence on phase separation.The recoveries of codeine and papaverine were 90.0100.2%and 99.3102.0%,respectively,from aqueous samples of P.papaveris by the proposed method.10第10页，本讲稿共16页6.Suppress

22、ion of deleterious effects of free silanols in liquid chromatography by imidazolium tetrafluoroborate ionic liquids AbstractSilica-based stationary phases are commonly used in liquid chromatography,but their surface acidity causes known problems,especially when separating basic compounds.Deleterious

23、 effects of free silanols are not fully removed by standard prevention procedures consisting in adding alkylamines or other amino quenchers to the eluents.We found that ionic liquids of the imidazolium tetrafluoroborate class,added to mobile phases at concentrations of 0.51.5%(v/v),blocked silanols

24、and provided excellent thin-layer chromatographic separations of strongly basic drugs which were otherwise not eluted,even with neat acetonitrile as the mobile phase.The silanol suppressing potency of imidazolium tetrafluoroborates was demonstrated to markedly exceed that of the standard mobile phas

25、e additives,like triethylamine,dimethyloctylamine and ammonia.The proposed new mobile phase additives were also demonstrated to provide reliable lipophilicity parameters of base drug analytes as determined by gradient mode of high-performance liquid chromatography.By applying the readily available a

26、nd environmentally friendly imidazolium tetrafluoroborate ionic liquids,simple and efficient means of improvement of liquid chromatographic analysis of organic bases were elaborated.11第11页，本讲稿共16页7.Reduction of silano philic interactions in liquid chromatography with the use of ionic liquids Abstrac

27、tA suppression of silano philic interactions by the selected ionic liquids added to the mobile phase in thin-layer chromatography(TLC)and high-performance liquid chromatography(HPLC)is reported.Acetonitrile was used as the eluent,alone or with various concentrations of water and phosphoric buffer pH

28、 3.Selectivity of the normal(NP)and the reversed(RP)stationary phase material was examined using a series of proton-acceptor basic drugs analytes.The ionic liquids studied appeared to significantly affect analyte retention in NP-TLC,RP-TLC and RP-HPLC systems tested.Consequently,the increased separa

29、tion selectivity was attained.Due to ionic liquid additives to eluent even analytes could be chromatographed,which were not eluted from the silica-based stationary phase materials with 100%of acetonitrile in the mobile phase.Addition of ionic liquid already in very small concentration(0.5%,v/v)could

30、 reduce the amount of acetonitrile used during the optimization of basic analytes separations in TLC and HPLC systems.Moreover,the influence of temperature on the separation of basic analytes was demonstrated and considered in practical HPLC method development.12第12页，本讲稿共16页8.Determination of Organo

31、phosphorous Pesticides in Water Samples Using Ionic Liquid-based Liquid Phase Micro extraction Coupled with High Performance Liquid ChromatographyXie AbstractA novel method for the determination of three organophosphorous pesticides(phorate,parathion and poxim)in water samples has been developed usi

32、ng ionic liquid-based liquid-phase microextraction coupled with high performance liquid chromatography.The influence of extraction parameters including extraction solvent,the volume ratio of extraction solvent to sample aqueous,extraction time,extraction temperature and stirring rate was investigate

33、d.1-butyl-3-methylimi dazolium hexafluorophosphate was used as extraction solvent and displayed particular advantages compared with volatile organic solvents such as benzene,hexane and acetone.The proposed method provided enrichment folds of 665,630 and 553 for phorate,parathion and poxim,respective

34、ly.The method had good linear range of 0.01-0.1 L/L and the limits of detectionof the three pesticides were in the range of 0.001-0.01 L/L.The RSD of matrix spiked samples were 3.4%,10.5%and 2.4%for phorate,parathion and poxim,respectively.13第13页，本讲稿共16页9.Ionic liquids as additives in high performan

35、ce liquid chromatography:Analysis of amines and the interaction mechanism of ionic liquids AbstractAs novel solvents,ionic liquids have many applications in synthesis,catalysis and analytical separation,i.e.extraction and chromatography separation.In this paper,some amines including benzidine,benzyl

36、amine,N-ethylaniline and N,N-dimethylaniline are separated using ionic liquids as additives for the mobile phase in high performance liquid chromatography(HPLC).The effects of the length of alkyl chain or counterions on different ionic liquids and their concentrations on the separation of these anal

37、ytes are performed.The differences between ionic liquids and tetrabutylammonium bromide(TBA)on the separation of o-,m-,p-phthalic acids are compared and the results show that ionic liquids are ion-pair reagents in essence,although their hydrophobicity and hydrogen bonding also play important roles.1

38、4第14页，本讲稿共16页10.Analysis of Phenolic Compounds by Ionic Liquid Based Liquid Liquid Extraction Coupled with High Performance Liquid ChromatographyAbstractA method was investigated for the simultaneous determination of phenols in water by ionic liquid 12butyl232methylimidazolium hexafluorophosphate(C4

39、 mim PF6 )based liquid2liquid extraction coupled with high performance liquid chromatography.Some conditions thatmight affect the extraction efficiency such as pH value of aqueous phase,extraction time,volume of aqueous phase and salt concentration were optimized.The results indicated that the op ti

40、nal conditionswere pH 5.0,40 min of extraction time,60 mL of aqueous phase and no added salt,respectively.The enrichment factor of C4mim PF6 for phenol,42nitro2 phenol,22nitrophenol,2,42dimethylphenol and bisphenolA were compared with 12octanol.Under the op timal conditions,the enrichment factor of

41、ionic liquid for the five phenolswere in the range of 9-151.The detec2 tion limits of phenol,42nitrophenol,22nitrophenol,2,42dimethylphenol and bisphenol A were 2.0,0.9,013,1.8 and 1.1g/L(S/N=3),respectively.The p roposed method was app lied to the determination of the five phenols in tap,river,lake and waste water.Recoveries of the five phenols were in the range of87.19%-109.9%.15第15页，本讲稿共16页 谢 谢 观 赏16第16页，本讲稿共16页