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Capillary action planar chromatography

The most important tasks of capillary action planar chromatography in pharmaceutical analysis are summarized in Table 2. In general, it can be stated that although HPLC has superseded TLC in many application areas, TLC both in instrumentalized or in noninstrumentalized forms have remained as standard methods for solving many difficult analytical problems. [Pg.823]

Table 2 Applicability of Capillary Action Planar Chromatography in Pharmaceutical Analysis (Data for Part 8 of Table 1)... Table 2 Applicability of Capillary Action Planar Chromatography in Pharmaceutical Analysis (Data for Part 8 of Table 1)...
Recently TLC methods using chemically bonded stationaiy phases in combination with polar eluents have been published (23-27). Although the first official use of this type of capillary action planar chromatography was for the separation of digoxin and its related glycosides in USP (28), the principle has also been recommended by BP88 for the analysis of testosterone esters (29) it can be stated that straight phase (NP/TLC) on chemically bonded stationary phases, or reversed phase (RP/TLC) on chemically bonded stationary phases has not been widely used in steroid analysis. The potential of these techniques is evident, as demonstrated with some examples below. [Pg.975]

Capillary action planar chromatography advantageous and disadvantageous properties of, 819,820-821... [Pg.1092]

The main origin of multidimensional chromatography lies in planar chromatography. The development of paper chromatography, i.e. the partition between a liquid moving by capillary action across a strip of paper impregnated with a second liquid... [Pg.12]

A theoretical model whereby maximum peak capacity could be achieved by the use of 3-D planar chromatographic separation was proposed by Guiochon and coworkers (23-27). Unfortunately, until now, because of technical problems, this idea could not be realized in practice. Very recently, however, a special stationary phase, namely Empore silica TLC sheets, has now become available for realization of 3-D PC. This stationary phase, developed as a new separation medium for planar chromatography, contains silica entrapped in an inert matrix of polytetrafluoroethy-lene (PTFE) microfibrils. It has been established that the separating power is only ca. 60% of that of conventional TLC (28) this has been attributed to the very slow solvent migration velocity resulting from capillary action. [Pg.184]

Chromatographic plates can be connected for both capillary-controlled and forced-flow planar chromatography (FFPC), i.e. irrespective of whether capillary action or forced-flow is the driving force for the separation. The first technique is denoted as grafted planar chromatography (31), while the second is known as long distance (LD) OPLC, which uses heterolayers (32, 33). [Pg.186]

Planar chromatography The term used to describe chromatographic methods that make use of a flat stationary phase the mobile phase migrates across the surface by gravity or capillary action. [Pg.1115]

Planar chromatography type of chromatography where the stationary phase is a flat film in the form of a thin layer of material coated onto a rectangular glass or inert plastic support plate (TLC) or as a paper sheet (PC). The mobile phase moves through the stationary phase by capillary action. [Pg.539]

Thin layer chromatography, TLC a form of planar chromatography having a coating of a solid stationary phase, e.g. silica gel or alumina, on a plate of glass or inert plastic. The liquid mobile phase moves up the plate by capillary action, reverse phase TLC plates are available where a liquid stationary phase is immobilised on the solid support. The polarity of the mobile phase is carefully chosen to obtain the best separation see elutropic series. [Pg.544]

If the mobile phase is a gas or a supercritical fluid, it is necessary to let it flow through a tube, a so-called column, that contains the stationary phase. In the case of liquid chromatography one can choose between a column or planar geometry because the mobile phase can move through a sheet of paper or a thin layer by capillary action. If a column is used, the mobile phase is forced through it by pressure generated by a pump or by a gas stored in a pressurized cylinder. (As a preparative laboratory technique, liquid chromatography is also performed in columns packed with coarse stationary phases in this case simple hydrostatic pressme may be sufficient.)... [Pg.657]

Forced-flow development. Forced-flow planar chromatography is a development technique wherein pressure is used to aid the mobility of the developing solvent. Examples of this are over-pressure layer chromatography (OPLC) and over-pressure thin-layer chromatography (OPTLC). In the latter a forced-flow technique is used to decrease the development time and thus speed up the separations. A pump controls the speed of the mobile phase. Theoretically, this method is faster than when movement of the solvent is due to capillary action alone (normal TLC) and can be used to advantage if slow-moving viscous solvents are involved as developing solvents. [Pg.9]

Rotation planar chromatography (RPC) uses a centrifugal force for mobile phase migration, in addition to the capillary action. The size of the vapor space above the chromatographic plate is an essential criterion in RPC methods and, based on this, the methods are classified into four basic techniques, namely normal chamber RPC (N-RPC), microchamber RPC (M-RPC), ultra-microchamber RPC (U-RPC), and column RPC (C-RPC). [Pg.447]

Liquid chromatography occurs basically in two forms, as column liquid chromatography, where the stationary phase is confined in a tubular column, or as layer chromatography, where the stationary phase is arranged in the form of a planar bed. In column liquid chromatography the mobile phase is pumped through the bed of stationary phase, while in planar chromatography the mobile phase normally is driven by capillary action. [Pg.129]

In this chapter, nonpressurized planar chromatography, where the mobile phase migrates solely by capillary action, is discussed. Aspects of forced flow TLC are considered occasionally when appropriate. [Pg.129]

Preparative layer (planar) chromatography (PLC) is a liquid chromatographic technique in which the solvent (mobile phase) migrates through a porous support (stationary phase) either by capillary action or under the influence of forced flow with the aim of separating compounds in amounts of 10-1(X)0 mg (1). The compounds can be isolated for structure elucidation (MS, NMR, IR, UV, etc.), for various analytical purposes (e.g., further chromatography), or for determination of biological activity (2). [Pg.307]


See other pages where Capillary action planar chromatography is mentioned: [Pg.1101]    [Pg.1101]    [Pg.819]    [Pg.819]    [Pg.113]    [Pg.300]    [Pg.218]    [Pg.218]    [Pg.103]    [Pg.20]    [Pg.38]    [Pg.920]    [Pg.1000]    [Pg.763]    [Pg.848]    [Pg.183]    [Pg.123]    [Pg.131]    [Pg.916]    [Pg.11]    [Pg.118]    [Pg.29]    [Pg.307]    [Pg.313]    [Pg.325]    [Pg.508]    [Pg.29]   


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