Partition chromatography

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Partition chromatography theory and practice was introduced through the work and publications of Archer Martin and Richard Laurence Millington Synge during the 1940s. [1] They would later receive the 1952 Nobel Prize in Chemistry "for their invention of partition chromatography". [2]

Contents

Synopsis

The process of separating mixtures of chemical compounds by passing them through a column that contains a solid stationary phase that was eluted with a mobile phase (column chromatography) was well known at that time. [3] Chromatographic separation was considered to occur by an adsorption process whereby compounds adhered to a solid media and were washed off the column with a solvent, mixture of solvents, or solvent gradient. In contrast, Martin and Synge developed and described a chromatographic separation process whereby compounds were partitioned between two liquid phases similar to the separatory funnel liquid-liquid separation dynamic. This was an important departure, both in theory and inder equilibrium conditions. [4] Martin and Synge initially attempted to devise a method of performing a sequential liquid-liquid extraction with serially connected glass vessels that functioned as separatory funnels. [1] The seminal article presenting their early studies described a rather complicated instrument that allowed partitioning of amino acids between water and chloroform phases. The process was termed "counter-current liquid-liquid extraction." [5] Martin and Synge described the theory of this technique in reference to continuous fractional distillation described by Randall and Longtin. [6] This approach was deemed too cumbersome, so they developed a method of absorbing water onto silica gel as the stationary phase and using a solvent, such as chloroform, as the mobile phase. [7] This work was published in 1941 as "a new form of chromatogram employing two liquid phases." [8] The article describes both the theory in terms of the partition coefficient of a compound, and the application of the process to the separation of amino acids on a water-impregnated silica column eluted with a water:chloroform:n-butanol solvent mixture.

Impact on separation methodology

The previously described work of Martin and Synge impacted the development of the previously known column chromatography and inspired new forms of chromatography such as countercurrent distribution, [9] paper chromatography, [10] and gas-liquid chromatography which is more commonly known as gas chromatography. The modification of silica gel stationary phase led to many creative ways of modifying stationary phases in order to influence the separation characteristics. The most notable modification was the chemical bonding of alkane functional groups to silica gel to produce reversed-phase media. [11] The original problem that Martin and Synge encountered with devising an instrument that would employ two free-flowing liquid phases was solved by Lyman C. Craig in 1944, and commercial counter-current distribution instruments were used for many important discoveries. [12] The introduction of paper chromatography was an important analytical technique which gave rise to thin-layer chromatography. [13] Finally, gas-liquid chromatography, a fundamental technique in modern analytical chemistry, was described by Martin with coauthors A. T. James and G. Howard Smith in 1952. [14]

Related Research Articles

In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent called the mobile phase, which carries it through a system on which a material called the stationary phase is fixed. Because the different constituents of the mixture tend to have different affinities for the stationary phase and are retained for different lengths of time depending on their interactions with its surface sites, the constituents travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation.

<span class="mw-page-title-main">High-performance liquid chromatography</span> Technique in analytical chemistry

High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify specific components in mixtures. The mixtures can originate from food, chemicals, pharmaceuticals, biological, environmental and agriculture, etc, which have been dissolved into liquid solutions.

<span class="mw-page-title-main">Gas chromatography</span> Type of chromatography

Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.

<span class="mw-page-title-main">Archer Martin</span> British chemist

Archer John Porter Martin was a British chemist who shared the 1952 Nobel Prize in Chemistry for the invention of partition chromatography with Richard Synge.

<span class="mw-page-title-main">Paper chromatography</span> Separation of coloured chemicals on paper

Paper chromatography is an analytical method used to separate coloured chemicals or substances. It is now primarily used as a teaching tool, having been replaced in the laboratory by other chromatography methods such as thin-layer chromatography (TLC).

<span class="mw-page-title-main">Column chromatography</span> Method to isolate a compound in a mixture

Column chromatography in chemistry is a chromatography method used to isolate a single chemical compound from a mixture. Chromatography is able to separate substances based on differential adsorption of compounds to the adsorbent; compounds move through the column at different rates, allowing them to be separated into fractions. The technique is widely applicable, as many different adsorbents can be used with a wide range of solvents. The technique can be used on scales from micrograms up to kilograms. The main advantage of column chromatography is the relatively low cost and disposability of the stationary phase used in the process. The latter prevents cross-contamination and stationary phase degradation due to recycling. Column chromatography can be done using gravity to move the solvent, or using compressed gas to push the solvent through the column.

<span class="mw-page-title-main">Thin-layer chromatography</span> Technique used to separate non-volatile mixtures

Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures.

<span class="mw-page-title-main">Solid-phase extraction</span> Process to separate compounds by properties

Solid-phase extraction (SPE) is a solid-liquid extractive technique, by which compounds that are dissolved or suspended in a liquid mixture are separated, isolated or purified, from other compounds in this mixture, according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue.

Chiral column chromatography is a variant of column chromatography that is employed for the separation of chiral compounds, i.e. enantiomers, in mixtures such as racemates or related compounds. The chiral stationary phase (CSP) is made of a support, usually silica based, on which a chiral reagent or a macromolecule with numerous chiral centers is bonded or immobilized.

Countercurrent distribution is an analytical chemistry technique which was developed by Lyman C. Craig in the 1940s. Countercurrent distribution is a separation process that is founded on the principles of liquid–liquid extraction where a chemical compound is distributed (partitioned) between two immiscible liquid phases according to its relative solubility in the two phases. The simplest form of liquid-liquid extraction is the partitioning of a mixture of compounds between two immiscible liquid phases in a separatory funnel. This occurs in five steps: 1) preparation of the separatory funnel with the two phase solvent system, 2) introduction of the compound mixture into the separatory funnel, 3) vigorous shaking of the separatory funnel to mix the two layers and allow for mass transfer of compounds in and out of the phases, 4) The contents of the separatory funnel are allowed to settle back into two distinct phases and 5) the two phases are separated from each other by draining out the bottom phase. If a compound is insoluble in the lower phase it will distribute into the upper phase and stay in the separatory funnel. If a compound is insoluble in the upper phase it will distribute into the lower phase and be removed from the separatory funnel. If the mixture contains one or more compounds that are soluble in the upper phase and one or more compounds that are soluble in the lower phase, then an extraction has occurred. Often, an individual compound is soluble to a certain extent in both phases and the extraction is, therefore, incomplete. The relative solubility of a compound in two phases is known as the partition coefficient.

Reversed-phase liquid chromatography (RP-LC) is a mode of liquid chromatography in which non-polar stationary phase and polar mobile phases are used for the separation of organic compounds. The vast majority of separations and analyses using high-performance liquid chromatography (HPLC) in recent years are done using the reversed phase mode. In the reversed phase mode, the sample components are retained in the system the more hydrophobic they are.

<span class="mw-page-title-main">Hydrophilic interaction chromatography</span> Type of chromatography

Hydrophilic interaction chromatography is a variant of normal phase liquid chromatography that partly overlaps with other chromatographic applications such as ion chromatography and reversed phase liquid chromatography. HILIC uses hydrophilic stationary phases with reversed-phase type eluents. The name was suggested by Andrew Alpert in his 1990 paper on the subject. He described the chromatographic mechanism for it as liquid-liquid partition chromatography where analytes elute in order of increasing polarity, a conclusion supported by a review and re-evaluation of published data.

Micellar liquid chromatography (MLC) is a form of reversed phase liquid chromatography that uses an aqueous micellar solutions as the mobile phase.

Aqueous normal-phase chromatography (ANP) is a chromatographic technique that involves the mobile phase compositions and polarities between reversed-phase chromatography (RP) and normal-phase chromatography (NP), while the stationary phases are polar.

<span class="mw-page-title-main">Elution</span> Extraction of a material by washing with a solvent

In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent; as in washing of loaded ion-exchange resins to remove captured ions.

The history of chromatography spans from the mid-19th century to the 21st. Chromatography, literally "color writing", was used—and named— in the first decade of the 20th century, primarily for the separation of plant pigments such as chlorophyll and carotenoids. New forms of chromatography developed in the 1930s and 1940s made the technique useful for a wide range of separation processes and chemical analysis tasks, especially in biochemistry.

The Wool Industries Research Association was an industrial research organization in the United Kingdom. It later became the Wira Technology Group before being merged with the Shirley Institute in the 1989 to form the British Textile Technology Group. It was funded by a levy raised under powers from the Industrial Organisation and Development Act 1947 through the Wool Textile Research Council, established in 1950.

<span class="mw-page-title-main">Countercurrent chromatography</span>

Countercurrent chromatography is a form of liquid–liquid chromatography that uses a liquid stationary phase that is held in place by inertia of the molecules composing the stationary phase accelerating toward the center of a centrifuge due to centripetal force and is used to separate, identify, and quantify the chemical components of a mixture. In its broadest sense, countercurrent chromatography encompasses a collection of related liquid chromatography techniques that employ two immiscible liquid phases without a solid support. The two liquid phases come in contact with each other as at least one phase is pumped through a column, a hollow tube or a series of chambers connected with channels, which contains both phases. The resulting dynamic mixing and settling action allows the components to be separated by their respective solubilities in the two phases. A wide variety of two-phase solvent systems consisting of at least two immiscible liquids may be employed to provide the proper selectivity for the desired separation.

Droplet countercurrent chromatography was introduced in 1970 by Tanimura, Pisano, Ito, and Bowman. DCCC is considered to be a form of liquid-liquid separation, which includes countercurrent distribution and countercurrent chromatography, that employs a liquid stationary phase held in a collection of vertical glass columns connected in series. The mobile phase passes through the columns in the form of droplets. The DCCC apparatus may be run with the lower phase stationary and the upper phase being introduced to the bottom of each column. Or it may be run with the upper phase stationary and the lower phase being introduced from the top of the column. In both cases, the work of gravity is allowed influence the two immiscible liquids of different densities to form the signature droplets that rise or descend through the column. The mobile phase is pumped at a rate that will allow droplets to form that maximize the mass transfer of a compound between the upper and lower phases. Compounds that are more soluble in the upper phase will travel quickly through the column, while compounds that are more soluble in the stationary phase will linger. Separation occurs because different compounds distribute differently, in a ratio called the partition coefficient, between the two phases.

Chiral analysis refers to the quantification of component enantiomers of racemic drug substances or pharmaceutical compounds. Other synonyms commonly used include enantiomer analysis, enantiomeric analysis, and enantioselective analysis. Chiral analysis includes all analytical procedures focused on the characterization of the properties of chiral drugs. Chiral analysis is usually performed with chiral separation methods where the enantiomers are separated on an analytical scale and simultaneously assayed for each enantiomer.

References

  1. 1 2 Ettre, Leslie S. (2001). "The Birth of Partition Chromatography". LCGC. 19 (5): 506–512. INIST   990422.
  2. ↑ "The Nobel Prize in Chemistry 1952". Nobel Media AB. Retrieved 4 February 2021.
  3. ↑ Pakhomov, V. P. (2003). "Chromatography in Pharmaceutical Chemistry (100 Years of the Discovery of Chromatography by M. S. Tswett)". Pharmaceutical Chemistry Journal. 37 (8): 451–452. doi:10.1023/A:1027324501053. S2CID   22507057.
  4. ↑ Schindler, Hans (November 1957). "Notes on the history of the separatory funnel". Journal of Chemical Education. 34 (11): 528. Bibcode:1957JChEd..34..528S. doi:10.1021/ed034p528.
  5. ↑ Martin, A. J. P.; Synge, R. L. M. (1 January 1941). "Separation of the higher monoamino-acids by counter-current liquid-liquid extraction: the amino-acid composition of wool". Biochemical Journal. 35 (1–2): 91–121. doi:10.1042/bj0350091. PMC   1265473 . PMID   16747393.
  6. ↑ Randall, Merle; Longtin, Bruce (September 1938). "Separation Processes: General Method of Analysis". Industrial & Engineering Chemistry. 30 (9): 1063–1067. doi:10.1021/ie50345a028.
  7. ↑ Whelan, William J. (1 May 2001). "Partition Chromatography Revisited". IUBMB Life. 51 (5): 329–330. doi: 10.1080/152165401317190851 . PMID   11699880.
  8. ↑ Martin, A. J. P.; Synge, R. L. M. (1 December 1941). "A new form of chromatogram employing two liquid phases. A theory of chromatography. 2. Application to the micro-determination of the higher monoamino-acids in proteins". Biochemical Journal. 35 (12): 1358–1368. doi:10.1042/bj0351358. PMC   1265645 . PMID   16747422.
  9. ↑ Craig, Lyman C. (October 1944). "Identification of small amounts of organic compounds by distribution studies: II. Separation by counter-current distribution". Journal of Biological Chemistry. 155 (2): 519–534. doi: 10.1016/S0021-9258(18)51183-2 .
  10. ↑ Consden, R.; Gordon, A. H.; Martin, A. J. P. (1944). "Qualitative analysis of proteins: A partition chromatographic method using paper". Biochemical Journal. 38 (3): 224–232. doi:10.1042/bj0380224. PMC   1258072 . PMID   16747784.
  11. ↑ Horvath, C.; Melander, W. (1 September 1977). "Liquid Chromatography with Hydrocarbonaceous Bonded Phases; Theory and Practice of Reversed Phase Chromatography". Journal of Chromatographic Science. 15 (9): 393–404. doi:10.1093/chromsci/15.9.393.
  12. ↑ Moore, Stanford (1978). "Lyman Creighton Craig 1906-1974". National Academy of Sciences Biographical Memoirs: 49–77. Retrieved 2016-02-26.
  13. ↑ Martin, A J P (June 1950). "Partition Chromatography". Annual Review of Biochemistry. 19 (1): 517–542. doi:10.1146/annurev.bi.19.070150.002505. PMID   14771840.
  14. ↑ James, A. T.; Martin, A. J. P.; Smith, G. Howard (1 October 1952). "Gas-liquid partition chromatography: the separation and micro-estimation of ammonia and the methylamines". Biochemical Journal. 52 (2): 238–242. doi:10.1042/bj0520238. PMC   1197975 . PMID   13018213.
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