Sc kSc k l thut ng chung cho mt tp hp cc k thut phng th nghim tch hn hp . The mixture is dissolved in a fluid called the "mobile phase", which carries it through a structure holding another material called the "stationary phase". Hn hp ny c ha tan trong mt cht lng gi l "pha ng", c th mang theo n thng qua mt cu trc t chc vt cht khc c gi l pha "tnh". The various constituents of the mixture travel at different speeds, causing them to separate. Cc thnh phn khc nhau ca hn hp cht di chuyn tc khc nhau, lm cho chng ring bit. The separation is based on differential partitioning between the mobile and stationary phases. S phn tch ny da trn phn vng khc bit gia cc pha ng trn pha tnh. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus changing the separation. Sc k ln u tin c s dng bi cc nh khoa hc Nga Michael Tsvet vo nm 1900. He continued to work with chromatography in the first decade of the 20th century, primarily for the separation of plant pigments such as chlorophyll , carotenes , and xanthophylls . ng tip tc lm vic vi sc k trong thp nin u ca th k 20, ch yu cho vic tch cc sc t thc vt chng hn nh cht dip lc, carotenes , v xanthophylls. Since these components have different colors (green, orange, and yellow, respectively) they gave the technique its name. K t khi cc thnh phn ny c mu sc khc nhau (mu xanh l cy, cam, v mu vng, tng ng) cho cc k thut tn ca n. New types of chromatography developed during the 1930s and 1940s made the technique useful for many separation processes . Cc loi mi ca sc k pht trin trong nhng nm 1930 v 1940 c thc hin cho nhiu quy trnh tch . Chromatography technique developed substantially as a result of the work of Archer John Porter Martin and Richard Laurence Millington Synge during the 1940s and 1950s.Sc k k thut pht trin ng k nh l kt qu ca Archer John Porter Martin v Richard Laurence Millington Synge trong nhng nm 1940 v 1950. They established the principles and basic techniques of partition chromatography, and their work encouraged the rapid development of several chromatographic methods: paper chromatography , gas chromatography , and what would become known as high performance liquid chromatography . H thnh lp cc nguyn tc v k thut c bn ca sc k phn vng, v cng vic ca h khuyn khch s pht trin nhanh chng ca mt s phng php sc k: sc k giy, sc k kh, v nhng g c bit n nh sc k lng hiu nng cao. Since then, the technology has advanced rapidly. K t , cng ngh tin tin nhanh chng. Researchers found that the main principles of Tsvet's chromatography could be applied in many different ways, resulting in the different varieties of chromatography described below. Nh nghin cu thy rng cc nguyn tc chnh ca sc k Tsvet c th c p dng trong nhiu cch khc nhau, kt qu l cc dng khc nhau ca sc k m t di y. Advances are continually improving the technical performance of chromatography, allowing the separation of increasingly similar molecules. Tin b lin tc ci thin hiu sut k thut sc k, cho php tch cc phn t ngy cng ging nhau.

v sc k The analyte is the substance to be separated during chromatography.Cht phn tch l cht c tch ra trong qu trnh sc k. Analytical chromatography is used to determine the existence and possibly also the concentration of analyte(s) in a sample .Phn tch sc k c s dng xc nh s tn ti v nng ca cht phn tch (s) trong mt mu . A bonded phase is a stationary phase that is covalently bonded to the support particles or to the inside wall of the column tubing. Mt giai on ngoi quan l mt giai on ph lin kt cng ha tr ngoi quan h tr cc ht hoc cc vch bn trong ca ng ct .

A chromatogram is the visual output of the chromatograph. Sc l hnh nh sc k. In the case of an optimal separation, different peaks or patterns on the chromatogram correspond to different components of the separated mixture.Trong trng hp ca mt tch ti u, cc nh khc nhau hoc cc mu trn sc tng ng vi thnh phn khc nhau ca hn hp tch ra. A chromatograph is equipment that enables a sophisticated separation eg gas chromatographic or liquid chromatographic separation.Chromatography is a physical method of separation in which the components to be separated are distributed between two phases, one of which is stationary (stationary phase) while the other (the mobile phase) moves in a definite direction. Sc k l mt phng php vt l tch bit trong cc thnh phn c tch ra c phn phi gia hai giai on, trong c vn phng phm (giai on vn phng phm), trong khi khc (giai on di ng) di chuyn theo mt hng nht nh. The eluate is the mobile phase leaving the column. Eluate l giai on in thoi di ng ri khi ct . The eluent is the solvent that will carry the analyte. Eluent l dung mi s mang cc cht phn tch . An eluotropic series is a list of solvents ranked according to their eluting power. Mt lot eluotropic l danh sch cc dung mi c xp hng theo quyn lc ca h ty ra. An immobilized phase is a stationary phase which is immobilized on the support particles, or on the inner wall of the column tubing. Mt giai on bt ng l mt giai on vn phng phm m l c nh cc ht h tr, hoc trn bc tng bn trong ca ng ct. The mobile phase is the phase which moves in a definite direction. Giai on di ng l giai on di chuyn theo mt hng xc nh . It may be a liquid (LC and Capillary Electrochromatography (CEC)), a gas (GC), or a supercritical fluid (supercritical-fluid chromatography, SFC). N c th l mt cht lng (LC Electrochromatography mao mch (CEC)), mt cht kh (GC), hoc mt cht lng siu ti hn (-sc k cht lng siu ti hn, SFC). The mobile phase consists of the sample being separated/analyzed and the solvent that moves the sample through the column. Giai on di ng bao gm cc mu c tch ra / phn tch v cc dung mi, di chuyn cc mu thng qua ct. In the case of HPLC the mobile phase consists of a non-polar solvent(s) such as hexane in normal phase or polar solvents in reverse phase chromotagraphy and the sample being separated. Trong trng hp ca HPLC , pha ng bao gm mt dung mi khng phn cc (s) nh hexane trong giai on bnh thng hoc cc dung mi cc trong chromotagraphy giai on o ngc v mu b tch . The mobile phase moves through the chromatography column (the stationary phase) where the sample interacts with the stationary phase and is separated. Di chuyn giai on di ng thng qua ct sc k (giai on vn phng phm), ni cc mu tng tc vi pha tnh v c tch ra. Preparative chromatography is used to purify sufficient quantities of a substance for further use, rather than analysis. Chun bi sc k c s dng lm sch s lng ca mt cht tip tc s dng, hn l phn tch. The retention time is the characteristic time it takes for a particular analyte to pass through the system (from the column inlet to the detector) under set conditions. Thi gian lu gi l thi gian c trng cn cho mt cht phn tch c th vt qua thng qua h thng (t u vo ct pht hin) theo iu kin quy nh. See also: Kovats' retention index Xem thm: ch s duy tr Kovats

The sample is the matter analyzed in chromatography. Mu l vn phn tch sc k. It may consist of a single component or it may be a mixture of components. N c th bao gm mt thnh phn duy nht hoc n c th l mt hn hp ca cc thnh phn. When the sample is treated in the course of an analysis, the phase or the phases containing the analytes of interest is/are referred to as the sample whereas everything out of interest separated from the sample before or in the course of the analysis is referred to as waste. Khi mu c x l trong qu trnh phn tch, giai on hoc cc giai on c cha cc cht phn tch quan tm l / c gi l mu trong khi tt c mi th ra quan tm tch ra t mu trc khi hoc trong qu trnh phn tch c gi l cht thi. The solute refers to the sample components in partition chromatography. Tan cp n cc thnh phn mu trong sc k phn vng. The solvent refers to any substance capable of solubilizing other substance, and especially the liquid mobile phase in LC. Dung mi dng ch bt k cht no c kh nng cc cht khc solubilizing, v c bit l giai on in thoi di ng cht lng trong LC. The stationary phase is the substance which is fixed in place for the chromatography procedure. Giai on vn phng phm l cht c c nh ti ch cho cc th tc sc k. Examples include the silica layer in thin layer chromatography V d nh silica lp trong sc k lp mng

Chromatography is based on the concept of partition coefficient. Sc k da trn cc khi nim v h s phn vng. Any solute will partition between two immissible solvents. Bt k phn vng s tan gia hai dung mi immissible. When we make one solvent immobile (by adsorption on a solid support matrix) and another mobile it results in most common applications of chromatography. Khi chng ti thc hin mt trong dung mi bt ng (bng cch hp ph vo mt ma trn h tr vng chc) v mt in thoi di ng, kt qu trong hu ht cc ng dng ph bin ca sc k. If matrix support is polar (eg paper, silica etc.) it is forward phase chromatography, and if it is non polar (C-18) it is reverse phase. Nu ma trn h tr l cc (v d nh giy, silica ...) n l chuyn tip giai on sc k, v nu n l khng cc (C-18), n l o ngc giai on.

K thut bi hnh dng ging sc k[ edit ] Column chromatography [ sa ] sc k ctFor more details on this topic, see Column chromatography . bit thm chi tit v ch ny, sc k ct . Column chromatography is a separation technique in which the stationary bed is within a tube. Ct sc k l mt k thut tch ging tnh trong mt ng. The particles of the solid stationary phase or the support coated with a liquid stationary phase may fill the whole inside volume of the tube (packed column) or be concentrated on or along the inside tube wall leaving an open, unrestricted path for the mobile phase in the middle part of the tube (open tubular column). Cc ht ca pha tnh rn hoc h tr ph vi mt giai on vn phng phm lng c th lp y ton b khi lng bn trong ca ng (ct ng gi) hoc c tp trung dc theo bc tng bn trong ng li mt con ng m, khng hn ch cho giai on in thoi di ng trong phn gia ca ng (m ng ct). Differences in rates of movement through the medium are calculated to different retention times of the sample. [ 1 ] S khc bit v t l chuyn ng qua mi trng c tnh ton thi gian lu khc nhau ca mu . [1 ] In 1978, WC Still introduced a modified version of column chromatography called flash column chromatography (flash). [ 2 ] [ 3 ] The technique is very similar to the traditional column chromatography, except for that the solvent is driven through the column by applying

positive pressure. Trong nm 1978, WC Tuy nhin gii thiu mt phin bn sa i ca sc k ct c gi l sc k ct n flash (flash ). [ 2] [ 3] K thut ny l rt tng t nh sc k ct truyn thng, tr trng hp cc dung mi c iu khin thng qua cc ct bng cch p dng tch cc p lc. This allowed most separations to be performed in less than 20 minutes, with improved separations compared to the old method. iu ny cho php hu ht cc phn tch c thc hin trong t hn 20 pht, vi s phn ly trong ci thin so vi phng php c. Modern flash chromatography systems are sold as pre-packed plastic cartridges, and the solvent is pumped through the cartridge. H thng sc k n flash hin i c bn nh cc hp mc ng gi sn bng nha, v dung mi c bm thng qua cc hp mc. Systems may also be linked with detectors and fraction collectors providing automation. H thng cng c th c lin kt vi my pht hin v thu phn cung cp t ng ha. The introduction of gradient pumps resulted in quicker separations and less solvent usage. Vic gii thiu my bm gradient trong phn tch nhanh hn v s dng t dung mi. In expanded bed adsorption , a fluidized bed is used, rather than a solid phase made by a packed bed. Trong ging hp th m rng , mt tng si c s dng, ch khng phi l mt pha rn c thc hin bi mt ging ng gi. This allows omission of initial clearing steps such as centrifugation and filtration, for culture broths or slurries of broken cells. iu ny cho php b st cc bc thanh ton b tr ban u nh ly tm v lc, nc canh vn ha hoc slurries ca cc t bo b hng.

[ edit ] Planar chromatography [ sa ] Planar sc kPlanar chromatography is a separation technique in which the stationary phase is present as or on a plane. Planar sc k l mt k thut tch, trong giai on vn phng phm l hin ti hoc trn mt my bay. The plane can be a paper, serving as such or impregnated by a substance as the stationary bed ( paper chromatography ) or a layer of solid particles spread on a support such as a glass plate ( thin layer chromatography ). Chic my bay c th c mt bi bo, phc v nh vy hoc thm tm mt cht nh ging vn phng phm ( giy sc k ) hoc mt lp cc ht rn ly lan trn mt h tr chng hn nh mt tm thy tinh (sc k lp mng ). Different compounds in the sample mixture travel different distances according to how strongly they interact with the stationary phase as compared to the mobile phase. Cc hp cht khc nhau trong hn hp mu i khong cch khc nhau theo cch mnh m chng tng tc vi pha tnh so vi giai on in thoi di ng. The specific Retention factor (R f ) of each chemical can be used to aid in the identification of an unknown substance. Duy tr yu t c th (R f) ca tng ha cht c th c s dng h tr trong vic xc nh cc mt cht khng r. [ edit ] Paper chromatography [ sa ] giy sc k For more details on this topic, see Paper chromatography . bit thm chi tit v ch ny, sc k giy . Paper chromatography is a technique that involves placing a small dot or line of sample solution onto a strip of chromatography paper . Giy sc k l mt k thut bao gm vic t mt du chm nh hoc dng dung dch mu vo mt di giy sc k . The paper is placed in a jar containing a shallow layer of solvent and sealed. Bi vit c t trong mt ci l c cha mt lp nng ca dung mi v ng du . As the solvent rises through the paper, it meets the sample mixture which starts to travel up the paper with the solvent. Khi tng dung mi thng qua t giy, n p ng hn hp mu bt u i du lch ln giy vi dung mi. This paper is made of cellulose, a polar substance, and the compounds within the mixture travel farther if they are non-polar. Bi vit ny c lm t cellulose, mt cht cc, v cc hp cht trong hn hp i du lch xa hn nu h khng phn cc. More polar substances bond with the cellulose paper more quickly, and therefore do not travel as far. Tri phiu cc cht vi giy cellulose mt cch nhanh chng hn, v do khng i du lch xa.

[ edit ] Thin layer chromatography [ sa ] sc k lp mng For more details on this topic, see Thin layer chromatography . bit thm chi tit v ch ny, sc k lp mng . Thin layer chromatography (TLC) is a widely employed laboratory technique and is similar to paper chromatography . Sc k lp mng (TLC) l mt k thut phng th nghim c s dng rng ri v l tng t nh sc k giy. However, instead of using a stationary phase of paper, it involves a stationary phase of a thin layer of adsorbent like silica gel , alumina , or cellulose on a flat, inert substrate . Tuy nhin, thay v s dng mt giai on vn phng phm giy, n lin quan n mt giai on vn phng phm ca mt lp mng hp th nh silica gel , nhm , hoc cellulose phng tr, cht nn . Compared to paper, it has the advantage of faster runs, better separations, and the choice between different adsorbents. So vi giy, n c li th chy nhanh hn, phn tch tt hn, v s la chn gia cc cht ht bm khc nhau. For even better resolution and to allow for quantification, high-performance TLC can be used. i vi phn gii tt hn v cho php nh lng, TLC hiu sut cao c th c s dng.

[ edit ] Displacement chromatography [ sa ] Displacement sc kThe basic principle of displacement chromatography is: A molecule with a high affinity for the chromatography matrix (the displacer) will compete effectively for binding sites, and thus displace all molecules with lesser affinities. [ 4 ] There are distinct differences between displacement and elution chromatography. Cc nguyn tc c bn ca sc k chuyn l: Mt phn t c i lc cao i vi ma trn sc k (displacer) s cnh tranh c hiu qu cho cc trang web lin kt, v do thay tt c cc phn t c i lc thp hn. [4] C s khc bit r rt gia di di v ra gii sc k . In elution mode, substances typically emerge from a column in narrow, Gaussian peaks. Trong ch ra gii, cc cht thng xut hin t mt ct hp, nh Gaussian. Wide separation of peaks, preferably to baseline, is desired in order to achieve maximum purification. Wide tch nh ni, u tin c bn, l mong mun t c thanh lc ti a. The speed at which any component of a mixture travels down the column in elution mode depends on many factors. Tc m bt c thnh phn no ca hn hp i xung ct trong ch ra gii ph thuc vo nhiu yu t. But for two substances to travel at different speeds, and thereby be resolved, there must be substantial differences in some interaction between the biomolecules and the chromatography matrix. Nhng i vi hai cht di chuyn vi tc khc nhau, v do c gii quyt, th phi c s khc bit ng k trong mt s tng tc gia cc phn t sinh hc v ma trn sc k. Operating parameters are adjusted to maximize the effect of this difference. Thng s vn hnh c iu chnh ti a ha nh hng ca s khc bit ny. In many cases, baseline separation of the peaks can be achieved only with gradient elution and low column loadings. Trong nhiu trng hp, ng c s tch cc nh ni c th t c ch vi ra gii gradient v tri ct thp. Thus, two drawbacks to elution mode chromatography, especially at the preparative scale, are operational complexity, due to gradient solvent pumping, and low throughput, due to low column loadings. Nh vy, hai tr ngi i vi ch ra gii sc k, c bit l quy m d bi, l hot ng phc tp, do thng Gradient bm dung mi, v thp, do tri ct thp. Displacement chromatography has advantages over elution chromatography in that components are resolved into consecutive zones of pure substances rather than peaks. Chuyn sc k c li th v sc k ra gii trong cc thnh phn c gii quyt vo khu lin tip ca cht tinh khit ch khng phi l "nh ni". Because the process takes advantage of the nonlinearity of the isotherms, a larger column feed can be separated on a given column with the purified components recovered at significantly higher concentrations. Bi v qu trnh ny c li th ca cc phi tuyn ca isotherms, mt ngun cp d liu ct ln hn c th c tch ra trn mt ct vi cc thnh phn tinh khit phc hi nng cao hn ng k.

[ edit ] Techniques by physical state of mobile phase [ sa ] K thut vt l ca nh nc giai on in thoi di ng[ edit ] Gas chromatography [ sa ] Sc k khFor more details on this topic, see Gas chromatography . bit thm chi tit v ch ny, sc k kh . Gas chromatography (GC), also sometimes known as Gas-Liquid chromatography, (GLC), is a separation technique in which the mobile phase is a gas. Sc k kh (GC), cng i khi c gi l kh, sc k lng, (GLC), l mt k thut tch, trong giai on di ng l mt cht kh. Gas chromatography is always carried out in a column, which is typically "packed" or "capillary" (see below) . Sc k kh lun lun thc hin trong mt ct, m thng l "ng gi" hay "mao mch" (xem di y). Gas chromatography (GC) is based on a partition equilibrium of analyte between a solid stationary phase (often a liquid silicone-based material) and a mobile gas (most often Helium). Sc k kh (GC) l da trn mt phn vng cn bng ca cht phn tch gia mt giai on vn phng phm rn (thng da trn vt liu silicon-mt cht lng) v kh t mt in thoi di ng (thng xuyn nht Helium). The stationary phase is adhered to the inside of a small-diameter glass tube (a capillary column) or a solid matrix inside a larger metal tube (a packed column). Giai on vn phng phm c tn trng bn trong mt ng thy tinh c ng knh nh (mt ct mao mch) hoc mt ma trn vng chc bn trong mt ng kim loi ln hn (mt ct ng gi). It is widely used in analytical chemistry ; though the high temperatures used in GC make it unsuitable for high molecular weight biopolymers or proteins (heat will denature them), frequently encountered in biochemistry , it is well suited for use in the petrochemical , environmental monitoring and remediation , and industrial chemical fields. S dng rng ri trong ha phn tch , mc d nhit cao c s dng trong GC lm cho n khng ph hp vi biopolymers trng lng phn t cao hoc protein (nhit s lm bin tnh chng), thng xuyn gp phi trong ha sinh, n l rt thch hp s dng trong ha du , gim st mi trng v khc phc , v cc lnh vc ha cht cng nghip . It is also used extensively in chemistry research. N cng c s dng rng ri trong nghin cu ha hc.

sc k lng

Preparative HPLC apparatus Chun bi HPLC b my Liquid chromatography (LC) is a separation technique in which the mobile phase is a liquid. Sc k lng (LC) l mt k thut tch, trong giai on di ng l mt cht lng. Liquid chromatography can be carried out either in a column or a plane. Sc k lng c th c thc hin hoc trong mt ct hoc mt mt phng. Present day liquid chromatography that

generally utilizes very small packing particles and a relatively high pressure is referred to as high performance liquid chromatography (HPLC). Cht lng sc k ngy nay thng s dng cc ht rt nh ng gi v p sut tng i cao c gi l sc k lng hiu nng cao (HPLC ). In HPLC the sample is forced by a liquid at high pressure (the mobile phase) through a column that is packed with a stationary phase composed of irregularly or spherically shaped particles, a porous monolithic layer , or a porous membrane. Trong HPLC mu c buc bng mt cht lng p sut cao (giai on di ng) thng qua mt ct c ng gi vi mt giai on vn phng phm bao gm t xut hoc cc ht hnh cu hnh mt lp xp nguyn khi, hoc mng xp. HPLC is historically divided into two different sub-classes based on the polarity of the mobile and stationary phases. HPLC l lch s c chia thnh hai lp ph khc nhau da trn s phn cc ca cc giai on in thoi di ng v vn phng phm. Methods in which the stationary phase is more polar than the mobile phase (eg toluene as the mobile phase, silica as the stationary phase) are termed normal phase liquid chromatography (NPLC) and the opposite (eg water-methanol mixture as the mobile phase and C18 = octadecylsilyl as the stationary phase) is termed reversed phase liquid chromatography (RPLC). Cc phng php, trong giai on vn phng phm l cc hn so vi giai on in thoi di ng (v d nh toluene l giai on in thoi di ng, silica pha tnh) c gi l sc k lng giai on bnh thng (NPLC) v (i din v d nh hn hp nc-methanol l giai on in thoi di ng v C18 = octadecylsilyl nh giai on vn phng phm) c gi l sc k lng (RPLC) giai on o ngc. Ironically the "normal phase" has fewer applications and RPLC is therefore used considerably more. Tr tru thay "giai on bnh thng" c nhng ng dng t hn v RPLC do c s dng ng k hn. Specific techniques which come under this broad heading are listed below. K thut c th thuc nhm ny rng c lit k di y. It should also be noted that the following techniques can also be considered fast protein liquid chromatography if no pressure is used to drive the mobile phase through the stationary phase. N cng nn c lu rng k thut sau y cng c th c coi l protein sc k lng nhanh chng nu p lc khng c s dng li xe giai on in thoi di ng thng qua cc giai on vn phng phm . See also Aqueous Normal Phase Chromatography . Dch nc bnh thng giai on sc k .

Mi quan h sc kFor more details on this topic, see Affinity chromatography . bit thm chi tit v ch ny, xem Affinity sc k . Affinity chromatography [ 5 ] is based on selective non-covalent interaction between an analyte and specific molecules. Mi quan h sc k [5] l da trn s tng tc khng cng ha tr la chn gia mt cht phn tch v cc phn t c th . It is very specific, but not very robust. N l rt c th, nhng khng phi l rt mnh m. It is often used in biochemistry in the purification of proteins bound to tags. N thng c dng trong sinh ha trong thanh lc cc protein lin kt vi cc th. These fusion proteins are labeled with compounds such as His-tags , biotin or antigens , which bind to the stationary phase specifically. Cc protein phn ng tng hp c dn nhn vi cc hp cht nh ca th , biotin hay khng nguyn , lin kt vi pha tnh c bit . After purification, some of these tags are usually removed and the pure protein is obtained. Sau khi thanh lc, mt s trong nhng th ny thng c loi b v protein tinh khit thu c. Affinity chromatography often utilizes a biomolecule's affinity for a metal (Zn, Cu, Fe, etc.). Mi quan h sc k thng s dng mi quan h ca mt phn t sinh hc cho mt kim loi (Zn, Cu, Fe, vv). Columns are often manually prepared. Ct thng t chun b. Traditional affinity columns are used as a preparative step to flush out unwanted biomolecules. Ct mi

quan h truyn thng c s dng nh l mt bc chun bi tun ra cc phn t sinh hc khng mong mun. However, HPLC techniques exist that do utilize affinity chromatogaphy properties. Tuy nhin, k thut HPLC tn ti m s dng ti sn chromatogaphy mi quan h. Immobilized Metal Affinity Chromatography (IMAC) is useful to separate aforementioned molecules based on the relative affinity for the metal (Ie Dionex IMAC). Bt ng kim loi Affinity sc k (IMAC) l hu ch tch cc phn t ni trn da trn cc mi quan h tng i cho cc kim loi (Tc l Dionex IMAC). Often these columns can be loaded with different metals to create a column with a targeted affinity. Thng th cc ct ny c th c np vi cc kim loi khc nhau to ra mt ct vi mt mi quan h mc tiu.

[ edit ] Supercritical fluid chromatography [ sa ] sc k cht lng siu ti hnFor more details on this topic, see Supercritical fluid chromatography . bit thm chi tit v ch ny, sc k cht lng siu ti hn . Supercritical fluid chromatography is a separation technique in which the mobile phase is a fluid above and relatively close to its critical temperature and pressure. Sc k cht lng siu ti hn l mt k thut tch, trong giai on in thoi di ng l mt cht lng trn v tng i gn vi nhit v p lc quan trng v.

[ edit ] Techniques by separation mechanism [ sa ] K thut ca c ch tch[ edit ] Ion exchange chromatography [ sa ] Ion sc k trao iFor more details on this topic, see Ion exchange chromatography . bit thm chi tit v ch ny, nhn thy sc k trao i ion . Ion exchange chromatography (usually referred to as ion chromatography) uses an ion exchange mechanism to separate analytes based on their respective charges. Sc k trao i ion (thng c gi l ion sc k) s dng mt c ch trao i ion vi cc cht phn tch ring bit da trn chi ph ca mnh. It is usually performed in columns but can also be useful in planar mode. N thng c thc hin trong ct nhng cng c th hu ch trong ch phng. Ion exchange chromatography uses a charged stationary phase to separate charged compounds including anions , cations , amino acids , peptides , and proteins . Ion sc k trao i s dng mt giai on tnh ph vn phng phm tch cc hp cht tch in bao gm cc anion , cation , amino acid , peptide , v cc protein. In conventional methods the stationary phase is an ion exchange resin that carries charged functional groups which interact with oppositely charged groups of the compound to be retained. Trong phng php thng thng giai on vn phng phm l mt nha trao i ion mang tnh nhm chc nng tng tc vi cc nhm tch in tri du ca hp cht c gi li . Ion exchange chromatography is commonly used to purify proteins using FPLC . Ion sc k trao i thng c s dng lm sch protein bng cch s dng FPLC .

[ edit ] Size-exclusion chromatography [ sa ] Kch thc loi tr sc kFor more details on this topic, see Size-exclusion chromatography . bit thm chi tit v ch ny, loi tr sc k Kch thc . Size-exclusion chromatography (SEC) is also known as gel permeation chromatography (GPC) or gel filtration chromatography and separates molecules according to their size (or more accurately according to their hydrodynamic diameter or hydrodynamic volume). Kch thc loi tr sc k (SEC) cng c bit n nh gel thm sc k (GPC) hoc sc k lc gel v tch cc phn t theo kch thc ca chng (hay chnh xc hn theo ng knh thy ng lc hc ca h hoc khi lng thy ng lc hc) . Smaller molecules are able to enter the pores of the media and, therefore, molecules are trapped and removed from the flow of the

mobile phase. Cc phn t nh hn c th nhp vo cc l chn lng ca cc phng tin truyn thng v, do , cc phn t b mc kt v loi b t dng chy ca giai on in thoi di ng. The average residence time in the pores depends upon the effective size of the analyte molecules. Thi gian c tr trung bnh trong cc l chn lng ph thuc vo kch thc hiu qu ca cc phn t cht phn tch. However, molecules that are larger than the average pore size of the packing are excluded and thus suffer essentially no retention; such species are the first to be eluted. Tuy nhin, cc phn t ln hn kch thc l chn lng trung bnh ca bao b c loi tr v do b c bn khng duy tr loi l ngi u tin c eluted. It is generally a low-resolution chromatography technique and thus it is often reserved for the final, "polishing" step of a purification. Ni chung l thp phn gii sc k k thut v do n thng c dnh cho cc bc cui cng, "nh bng" thanh lc mt. It is also useful for determining the tertiary structure and quaternary structure of purified proteins, especially since it can be carried out under native solution conditions. N cng hu ch xc nh c cu i hc v cu trc bc bn ca protein tinh khit, c bit l k t khi n c th c thc hin di iu kin gii php bn a.

[ edit ] Special techniques [ sa ] k thut c bit[ edit ] Reversed-phase chromatography [ sa ] o ngc pha sc kFor more details on this topic, see Reversed-phase chromatography . bit thm chi tit v ch ny, nhn thy o ngc pha sc k . Reversed-phase chromatography is an elution procedure used in liquid chromatography in which the mobile phase is significantly more polar than the stationary phase. o ngc pha sc k l mt quy trnh ra gii c s dng trong sc k lng, trong giai on in thoi di ng l cc nhiu hn ng k hn so vi pha tnh. This section requires expansion . Phn ny i hi phi m rng .

[ edit ] Two-dimensional chromatography [ sa ] sc k hai chiuIn some cases, the chemistry within a given column can be insufficient to separate some analytes. Trong mt s trng hp, thnh phn ha hc trong mt ct no c th l khng tch mt s cht phn tch. It is possible to direct a series of unresolved peaks onto a second column with different physico-chemical ( Chemical classification ) properties. N c th ch o mt lot cc nh ni cha c gii quyt vo mt ct th hai vi khc nhau l ha ( ha cht phn loi ) ti sn . Since the mechanism of retention on this new solid support is different from the first dimensional separation, it can be possible to separate compounds that are indistinguishable by one-dimensional chromatography. K t khi c ch duy tr h tr vng chc mi ny l khc nhau t s tch bit chiu u tin, n c th c c th hp cht ring bit m khng th phn bit bi sc k mt chiu. The sample is spotted at one corner of a square plate,developed, air-dried, then rotated by 90 and usually redeveloped in a second solvent system. Mu c pht hin ti mt gc ca mt tm hnh vung, c pht trin, khng kh kh, sau quay bng 90 v thng ti pht trin trong mt h thng dung mi th hai. This section requires expansion . Phn ny i hi phi m rng .

[ edit ] Simulated moving-bed chromatography [ sa ] sc k di chuyn ging m phngFor more details on this topic, see Simulated moving bed . bit thm chi tit v ch ny, thy m phng di chuyn ging . This section requires expansion . Phn ny i hi phi m rng .

[ edit ] Pyrolysis gas chromatography [ sa ] sc k kh nhit phn

Pyrolysis gas chromatography mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition to produce smaller molecules that are separated by gas chromatography and detected using mass spectrometry. Nhit phn sc k kh khi ph l mt phng php phn tch ha hc trong mu c lm nng phn hy sn xut cc phn t nh c phn cch bng sc k kh v pht hin bng cch s dng php o ph khi. Pyrolysis is the thermal decomposition of materials in an inert atmosphere or a vacuum. Nhit phn l s phn hy nhit ca vt liu trong mt bu khng kh tr, hoc chn khng. The sample is put into direct contact with a platinum wire, or placed in a quartz sample tube, and rapidly heated to 6001000 C. Mu c a vo tip xc trc tip vi mt dy bch kim, hoc t trong mt ng mu thch anh, v nhanh chng nng ln n 600-1000 C. Depending on the application even higher temperatures are used. Ty thuc vo cc ng dng nhit cn cao hn c s dng. Three different heating techniques are used in actual pyrolyzers: Isothermal furnace, inductive heating (Curie Point filament), and resistive heating using platinum filaments. Ba k thut t nng khc nhau c s dng trong pyrolyzers thc t: ng nhit, l si, si m cm ng (im Curie dy tc), v t nng in tr bng cch s dng si bch kim. Large molecules cleave at their weakest points and produce smaller, more volatile fragments. Tch cc phn t ln im yu nht ca h v to ra nhng mnh v nh hn, bin ng hn. These fragments can be separated by gas chromatography. Nhng mnh v ny c th c phn cch bng sc k kh. Pyrolysis GC chromatograms are typically complex because a wide range of different decomposition products is formed. Nhit phn GC sc k thng phc tp v mt lot cc sn phm phn hy khc nhau c hnh thnh. The data can either be used as fingerprint to prove material identity or the GC/MS data is used to identify individual fragments to obtain structural information. Cc d liu c th c s dng nh l du vn tay chng minh nhn dng vt cht hoc cc d liu GC / MS c s dng xc nh cc mnh v c nhn c c thng tin cu trc. To increase the volatility of polar fragments, various methylating reagents can be added to a sample before pyrolysis. tng s bin ng ca mnh cc, cc cht phn ng khc nhau methylating c th c thm vo mt mu trc khi nhit phn. Besides the usage of dedicated pyrolyzers, pyrolysis GC of solid and liquid samples can be performed directly inside Programmable Temperature Vaporizer (PTV) injectors that provide quick heating (up to 30 C/s) and high maximum temperatures of 600650 C. Bn cnh vic s dng pyrolyzers chuyn dng, nhit phn GC mu rn v cht lng c th c thc hin trc tip bn trong Vaporizer Nhit lp trnh (PTV) phun cung cp cho si m nhanh chng (ln n 30 C / s) v nhit ti a cao 600-650 C. This is sufficient for some pyrolysis applications. iu ny l cho mt s ng dng nhit phn. The main advantage is that no dedicated instrument has to be purchased and pyrolysis can be performed as part of routine GC analysis. u im chnh m khng c dng c chuyn dng c mua v nhit phn c th c thc hin nh l mt phn ca phn tch GC thng xuyn. In this case quartz GC inlet liners have to be used. Trong trng hp ny, thch anh GC lt u vo c th c s dng. Quantitative data can be acquired, and good results of derivatization inside the PTV injector are published as well. S liu nh lng c th c mua li, v kt qu tt ca derivatization bn trong vi phun PTV c cng b l tt.

[ edit ] Fast protein liquid chromatography [ sa ] nhanh protein sc k lngFor more details on this topic, see Fast protein liquid chromatography . bit thm chi tit v ch ny, sc k lng protein nhanh . Fast protein liquid chromatography (FPLC) is a term applied to several chromatography techniques which are used to purify proteins. Nhanh sc k lng protein (FPLC) l mt thut ng p dng mt s k thut sc k c s dng lm sch protein. Many of these techniques are identical to those carried out under high performance liquid chromatography,

however use of FPLC techniques are typically for preparing large scale batches of a purified product. Nhiu ngi trong s nhng k thut ny l ging ht nhau cho nhng ngi thc hin theo sc k lng hiu nng cao, tuy nhin s dng cc k thut FPLC thng chun b cho l hng quy m ln ca mt sn phm tinh khit.

sc k ngcFor more details on this topic, see Countercurrent chromatography . bit thm chi tit v ch ny, sc k ngc .

An example of a HPCCC system Mt v d ca mt h thng HPCCC Countercurrent chromatography (CCC) is a type of liquid-liquid chromatography, where both the stationary and mobile phases are liquids. Ngc sc k (CCC) l mt loi cht lng sc k lng, vn phng phm v cc giai on in thoi di ng l cht lng. The operating principle of CCC equipment requires a column consisting of an open tube coiled around a bobbin. Nguyn tc hot ng ca CCC thit b i hi phi c mt ct bao gm mt ng m cun xung quanh mt cun. The bobbin is rotated in a double-axis gyratory motion (a cardioid), which causes a variable gravity (G) field to act on the column during each rotation. Cun c lun chuyn trong mt chuyn ng hi chuyn hai trc (cardioid), gy ra mt trng hp dn (G) bin hnh ng ct trong qu trnh lun chuyn mi. This motion causes the column to see one partitioning step per revolution and components of the sample separate in the column due to their partitioning coefficient between the two immiscible liquid phases used. Chuyn ng ny gy ra cc ct xem mt bc phn vng mi cuc cch mng v cc thnh phn ca mu ring bit trong ct do h s phn vng ca h gia hai giai on khng th trn ln cht lng c s dng. There are many types of CCC available today. C rt nhiu loi CCC c ngy hm nay. These include HSCCC (High Speed CCC) and HPCCC (High Performance CCC). Chng bao gm HSCCC (High Speed CCC) v HPCCC (High Performance CCC). HPCCC is the latest and best performing version of the instrumentation available currently. HPCCC l phin bn mi nht v thc hin tt nht ca thit b c sn.

[ edit ] Chiral chromatography [ sa ] chiral sc kChiral chromatography involves the separation of stereoisomers. Sc k i xng lin quan n vic tch phn lp th. In the case of enantiomers, these have no chemical or physical differences apart from being three-dimensional mirror images. Trong trng hp ca enantiomers, khng c s khc bit ha hc hoc vt l ngoi vic b ba chiu hnh nh gng. Conventional chromatography or other separation processes are incapable of separating them. Sc k thng thng hoc cc qu trnh tch khc khng c kh nng tch chng. To enable chiral separations to take place, either the mobile phase or the stationary phase must themselves be made chiral, giving differing affinities between the analytes. Chiral chromatography HPLC columns (with a chiral stationary phase) in both normal and reversed phase are commercially available. kch hot tnh nng phn tch chiral din ra, mt trong

hai giai on di ng hoc giai on vn phng phm phi t c thc hin i xng, cho i lc khc nhau gia cc cht phn tch . chiral sc k HPLC ct (vi mt giai on vn phng phm chiral) trong giai on bnh thng v ngc li l thng mi c sn .

Sc k phn mmFrom Wikipedia, the free encyclopedia T Wikipedia, bch khoa ton th min ph

Jump to: navigation , search Bc ti: chuyn hng , tm kim A chromatography software , also known as a Chromatography data system (CDS), collects and analyzes chromatographic results delivered by chromatography detectors . Mt phn mm sc k, cng c bit n nh mt h thng d liu sc k (CDS), thu thp v phn tch sc k kt qu cung cp bi cc my d sc k. Many chromatography software packages are provided by manufacturers, and many of them only provide a simple interface to acquire data. Nhiu sc k cc gi phn mm c cung cp bi nh sn xut, v nhiu ngi trong s h ch cung cp mt giao din n gin c c d liu. They also provide different tools to analyze this data. H cng cung cp cc cng c khc nhau phn tch d liu ny. The most common tool is "integration": It computes simple areas to delimit peaks by adding valleys automatically or not. Cc cng c ph bin nht l "hi nhp": tnh din tch n gin phn nh cc nh ni bng cch thm vo cc thung lng t ng hay khng. Areas are computed between two valleys, a signal, and a baseline. Cc khu vc c tnh ton gia hai thung lng, mt tn hiu, v mt ng c s. Another tool is the "calibration". Cng c khc l "hiu chun". Next is a list of software providing these tools and many others: Tip theo l mt danh sch cc phn mm cung cp nhng cng c ny v nhiu ngi khc: Name Tn Chromatography software Sc k phn mm Publisher Control Analysis Comments Type Loi Nh xut bn Kim sot Phn tch Bnh lun Techsia Yes C GC GC Techsia Agilent limited XML, Macros Yes C LC LC Agilent hn ch XML, Macros Dionex GC / LC / IEX / MS Yes C Yes C Dionex GC / LC / IEX / MS Yes C Yes C GC/LC GC / LC

Malcom [ 1 ] Malcolm [1] ChemStation [ 2 ] ChemStation [2] Chromeleon [ 3 ] Chromeleon [3] Empower [ 4 ] Trao Waters Waters quyn cho [4] OpenChrom [ 5 ] OpenChrom [5]

Nguyn tcIn normal-phase chromatography, the stationary phase is polar and the mobile phase is nonpolar . Trong giai on sc k bnh thng, pha tnh l cc v giai on di ng l khng cc . In reversed phase we have just the opposite; the stationary phase is nonpolar and the mobile phase is polar. Trong giai on o ngc, chng ti c ch l ngc li, giai on vn phng phm l khng cc v giai on di ng l cc. Typical stationary phases for normalphase chromatography are silica or organic moieties with cyano and amino functional groups. Giai on in hnh vn phng phm cho sc k giai on bnh thng l silica hoc moieties hu c vi cyano v amino nhm chc nng. For reversed phase, alkyl hydrocarbons are the

preferred stationary phase; octadecyl (C18) is the most common stationary phase, but octyl (C8) and butyl (C4) are also used in some applications. i vi giai on o ngc , alkyl hydrocarbon l giai on vn phng phm a thch; octadecyl (C18) l giai on vn phng phm ph bin nht, nhng octyl (C8) v butyl (C4) cng c s dng trong mt s ng dng . The designations for the reversed phase materials refer to the length of the hydrocarbon chain. Cc ch nh cho cc ti liu giai on o ngc vi chiu di ca chui hydrocarbon. In normal-phase chromatography, the least polar compounds elute first and the most polar compounds elute last. Trong giai on sc k bnh thng, cc hp cht t nht l cc elute u tin v cc hp cht cc nht elute cui cng. The mobile phase consists of a nonpolar solvent such as hexane or heptane mixed with a slightly more polar solvent such as isopropanol , ethyl acetate or chloroform . Giai on di ng bao gm mt dung mi khng cc nh hexane hoc heptan trn vi mt dung mi nh hi nhiu cc isopropanol , acetate ethyl hoc chloroform . Retention increases as the amount of nonpolar solvent in the mobile phase increases. Duy tr tng lng dung mi khng cc trong tng giai on di ng. In reversed phase chromatography, the most polar compounds elute first with the most nonpolar compounds eluting last. Trong sc k pha o ngc, cc hp cht cc nht elute u tin vi cc hp cht khng cc nht ty ra cui cng. The mobile phase is generally a binary mixture of water and a miscible polar organic solvent like methanol , acetonitrile or THF . Giai on di ng ni chung l mt hn hp nh phn ca nc v th trn ln cc dung mi hu c nh methanol , acetonitrile hoc THF . Retention increases as the amount of the polar solvent (water) in the mobile phase increases. Duy tr tng ln khi s lng cc ca dung mi (nc) trong pha ng tng. Normal phase chromatography, an adsorptive mechanism, is used for the analysis of solutes readily soluble in organic solvents, based on their polar differences such as amines, acids, metal complexes, etc.. Sc k giai on bnh thng, mt adsorptive c ch, c s dng cho vic phn tch cc cht tan d dng ha tan trong cc dung mi hu c, da trn s khc bit cc ca h nh l cc amin, axit, khu phc hp kim loi, vv . Reversedphase chromatography, a partition mechanism, is typically used for separations by non-polar differences. o ngc pha sc k, mt c ch phn vng, thng c s dng cho phn tch s khc bit khng phn cc. The "hydride surfaces" distinguish the support material from other silica materials; most silica materials used for chromatography have a surface composed primarily of silanols (-Si-OH). "B mt hydride" phn bit cc ti liu h tr t cc vt liu silica khc, hu ht cc vt liu silica c s dng cho sc k c mt b mt bao gm ch yu ca silanols (- Si-OH). In a "hydride surface" the terminal groups are primarily -Si-H. Trong mt "b mt hydride" cc nhm thit b u cui ch yu l Si-H. The hydride surface can also be functionalized with carboxylic acids [1] and long-chain alkyl groups [2] . Cc b mt hydride cng c th c functionalized vi axit cacboxylic [1] v nhm alkyl chui di [2] . Mobile phases for ANPC are based on an organic solvent (such as methanol or acetonitrile) with a small amount of water; thus, the mobile phase is both "aqueous" (water is present) and "normal" (less polar than the stationary phase). Giai on in thoi di ng cho ANPC l da trn mt dung mi hu c (chng hn nh methanol hay acetonitrile) vi mt lng nh nc, do , giai on di ng l c hai "dung dch nc" (nc hin nay) v "bnh thng" (cc t hn so vi giai on vn phng phm ). Thus, polar solutes (such as acids and amines) are most strongly retained, with retention decreasing as the amount of water in the mobile phase increases. Do , cc cht tan (chng hn nh axit v amin) mnh m nht c gi li, vi gim lu gi nh l lng nc trong tng giai on di ng. Typically the amount of the nonpolar component in the mobile phase must be 60% or greater with the exact point of increased retention depending on the solute and the organic component of the mobile phase. Thng thng s lng ca thnh phn khng cc trong giai on in thoi di ng phi l 60% hoc cao hn vi im chnh xc duy tr tng ln ty thuc vo cht tan v cc thnh phn hu c ca giai on di ng. A true ANP stationary phase will be able

to function in both the reversed phase and normal phase modes with only the amount of water in the eluent varying. Mt ANP vn phng phm giai on thc s s c th hot ng trong c giai on v ch o ngc giai on bnh thng vi s tin ca nc khc nhau eluent. Thus a continuum of solvents can be used from 100% aqueous to pure organic. V vy, mt s lin tc ca cc dung mi c th c s dng t 100% dung dch nc tinh khit hu c. ANP retention has been demonstrated for a variety of polar compounds on the hydride based stationary phases (JJ Pesek, MT Matyska, J. Sep. Sci., in press [ citation needed ] ). Duy tr ANP c chng minh cho mt lot cc hp cht cc hydride da trn cc giai on vn phng phm (JJ Pesek, MT Matyska, J. Thng Chn Khoa hc, trn bo ch [cn dn ngun]) .

[ edit ] Features [ sa ] Cc tnh nngAn interesting feature of these phases is that both polar and nonpolar compounds can be retained over some range of mobile phase composition (organic/aqueous). Mt tnh nng th v ca giai on ny l c hai hp cht cc v khng cc c th c gi li trn mt s phm vi ca cc thnh phn pha ng (hu c / dung dch nc). The retention mechanism of polar compounds has not been elucidated yet for the silica hydride phases. C ch duy tr cc hp cht cc khng c lm sng t cho cc giai on hydride silica. This property distinguishes it from a pure HILIC (hydrophilic interaction chromatography) column where separation by polar differences is obtained, or a pure RP stationary phase on which separation by nonpolar differences in solutes is obtained with very limited secondary mechanisms operating. Ti sn ny phn bit n t HILIC tinh khit (a nc tng tc sc k) ct ni tch bit bi s khc bit cc thu c, hoc mt giai on RP tinh khit tnh tch bit bi s khc bit khng cc trong cht tan thu c vi iu hnh rt hn ch c ch th. Another important feature of the hydride-based phases is that for many analyses it is usually not necessary to use a high pH mobile phase to analyze polar compounds such as bases. Mt tnh nng quan trng ca giai on hydride l phn tch nhiu, n thng l khng cn thit s dng mt giai on pH di ng cao cp phn tch cc hp cht cc chng hn nh cn c. The aqueous component of the mobile phase usually contains from 0.1 to 0.5% formic or acetic acid, which is compatible with detector techniques that include mass spectral analysis. Cc thnh phn dung dch nc ca giai on in thoi di ng thng cha t 0,1 n 0,5% formic hoc axit axetic, l tng thch vi cc k thut pht hin bao gm phn tch quang ph khi lng.