Tswett

M. S. Tswett, the Polish botanist, in 1906 used adsorption columns in his investigations of plant pigments. It was not untU about 1930 that the method was used extensively by chemists. The most startling results have been obtained in the fields of plant pigments and natural products, but... 

A typical column chromatography experiment is outlined in Figure 12.4. Although the figure depicts a liquid-solid chromatographic experiment similar to that first used by Tswett, the design of the column and the physical state of the... 

In liquid-solid adsorption chromatography (LSC) the column packing also serves as the stationary phase. In Tswett s original work the stationary phase was finely divided CaCOa, but modern columns employ porous 3-10-)J,m particles of silica or alumina. Since the stationary phase is polar, the mobile phase is usually a nonpolar or moderately polar solvent. Typical mobile phases include hexane, isooctane, and methylene chloride. The usual order of elution, from shorter to longer retention times, is... 

Indeed, great emphasis was placed on the presentation of compounds in crystalline form for many years, early chromatographic procedures for the separation of natural substances were criticized because the products were not crystalline. None the less, the invention by Tswett (3) of chromatographic separation by continuous adsorption/desorption on open columns as applied to plant extracts was taken up by a number of natural product researchers in the 1930s, notably by Karrer (4) and by Swab and lockers (5). An early example (6) of hyphenation was the use of fluorescence spectroscopy to identify benzo[a]pyrene separated from shale oil by adsorption chromatography on alumina. 

M. Tswett, Physikalisch-Chemische Studier iiber das chlorophyll. Die absoiptionen , Ber. Dtsch. Botan. Ges 24 316 (1906). 

This thinking has carried through to the present day and is reflected in our choices of mobile-phase fluids in LC water, acetonitrile, methanol, tetrahydrofuran, hexane, etc., are still among our popular choices. However, these particular materials are completely dependent on the conditions of column temperature and outlet pressure. Tswett s original conditions at his column outlet, actually the earth-bound defaults we call ambient temperature and pressure, determined his solvent choices and continue to dominate our thinking today. 

A further thirty years were to pass before Kuhn and his co-workers (3) successfully repeated Tswetf s original work and separated lutein and xanthine from a plant extract. Nevertheless, despite the success of Kuhn et al and the validation of Tswett s experiments, the new technique attracted little interest and progress continued to be slow and desultory. In 1941 Martin and Synge (4) introduced liquid-liquid chromatography by supporting the stationary phase, in this case water, on silica in the form of a packed bed and used it to separate some acetyl amino acids. 

Tswett s initial column liquid chromatography method was developed, tested, and applied in two parallel modes, liquid-solid adsorption and liquid-liquid partition. Adsorption ehromatography, based on a purely physical principle of adsorption, eonsiderably outperformed its partition counterpart with mechanically coated stationary phases to become the most important liquid chromatographic method. This remains true today in thin-layer chromatography (TLC), for which silica gel is by far the major stationary phase. In column chromatography, however, reversed-phase liquid ehromatography using chemically bonded stationary phases is the most popular method. 

The Russian botanist N. S. Tswett is generally credited with the discovery of chromatography around the turn of the century [1]. He used a colunn of powdered calcium carbonate to separate... 

Principles and Characteristics Column liquid chromatography is the parent of all other types of chromatography. The technique used by Tswett is now called classical open-column liquid chromatography or simply LC. In column chromatography the stationary phase is contained in a column and the mobile phase flows... 

Carotenoids were discovered during the nineteenth century. Wachen in 1831 proposed the term carotene for the hydrocarbon pigment crystallized from carrot roots Berzelius called the more polar yellow pigments extracted from autumn leaves xanthophylls and Tswett separated many pigments by column chromatography and called the whole group carotenoids. ... 

In 1904 the Russian scientist Tswett coined the term chromatography (= colour writing) with regard to his work in separating plant pigments. Today, some of the most potent analytical methods available are chromatographic. 

M. Tswett. Physikalische-chemische Studien iiber das Chlorophyll. Die Adsorptionen. Ber. Deutschen Botan. Ges., 24(1906) 316-323. 

The development of chromatography was first described by M. S. Tswett and is generally credited to him [26], He initially separated chlorophylls using a column of calcium carbonate and various solvents. His basic setup for chromatography was, and still is, a stationary phase and a mobile phase. As the mobile phase carries components of a mixture across the stationary phase, they are separated from each other and come out of the setup at different times [27], The term chromatography came about because the compounds initially... 

Issaq HJ, Berezkin VG. Mikhail Semenovich Tswett the father of modern chromatography. In Issaq HJ (ed.), A Century of Separation Science. New York Marcel Dekker, Inc. 2002, pp. 19-26. 

Figure 3.3 outlines the similarities in those methods in which the polarity of the various test substances is an important consideration. All of these methods are essentially chromatographic, a word coined originally by Tswett in 1906 which now implies the separation of the components of a mixture by a system involving two phases, one of which is stationary and the other mobile. 

M. Tswett, Chlorophylls in Vegetal and Animal Worlds. Warszaw, 1910. 

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