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Straight-phase

Chapter 3 through Chapter 8 deal with the basic aspects of the practical uses of PLC. Chapter 3 describes sorbent materials and precoated layers for normal or straight phase (adsorption) chromatography (silica gel and aluminum oxide 60) and partition chromatography (silica gel, aluminum oxide 150, and cellulose), and precoated layers for reversed-phase chromatography (RP-18 or C-18). Properties of the bulk sorbents and precoated layers, a survey of commercial products, and examples of substance classes that can be separated are given. [Pg.8]

Sorbent Materials and Precoated Layers for Straight Phase... [Pg.41]

Alnminum Oxide Bnlk Materials for Straight Phase PLC.51... [Pg.41]

SORBENT MATERIALS AND PRECOATED LAYERS FOR STRAIGHT PHASE CHROMATOGRAPHY... [Pg.41]

The specific retention of sample molecules to be separated in a straight phase or adsorption chromatographic system is mainly determined by two factors their interactions with polar surface centers of the solid stationary phase, and by the different sample solubility in the rather nonpolar mobile phase. The most important interactions... [Pg.41]

The most frequently used sorbent type for straight phase chromatographic systems in planar chromatography is porous, nonsurface-modified silica gel. [Pg.42]

The important physical parameters that describe the chromatographic characteristics of silica gels suitable for straight phase chromatography are as follows ... [Pg.42]

Table 3.1 lists commercially available bulk silica gels for the manual preparation of PLC layers snitable for straight phase chromatography. These bulk silica gels are produced by different manufacturers, and in some cases they are offered with binding additives and fluorescent indicators. The data summarized in this table are traceable to product information from the concerned manufacturers. [Pg.43]

In Table 3.2 the preparative precoated silica gel plates for straight phase PLC from different mamrfacturers are summarized. Incomplete data are due to incomplete information received from the manufacturers. [Pg.43]

An extensive variety of substance classes have been separated using silica gel as the stationary phase in straight phase adsorption PLC. Some examples are the following ... [Pg.51]

Another fairly important stationary phase in straight phase PLC is aluminum oxide. Comparable with silica gel also in the case of aluminum oxides, hydroxyl groups at the surface of this adsorbent are responsible for the selective retention of sample molecules. The relevant physical parameters for the characterization of aluminum oxides suitable for straight phase PLC are the following ... [Pg.51]

Table 3.3 lists bulk aluminas for the preparation of homemade PLC plates for straight phase chromatography. [Pg.51]

To achieve better separation efficiency and reproducibility compared with handmade layers also in the case of aluminum oxides, precoated plates are available for straight phase PLC. They are listed in Table 3.4. [Pg.51]

Substance classes that can be separated by straight phase adsorption PLC on aluminum oxide stationary phases are, for example, alkaloids [17]. [Pg.51]

In contrast to straight phase or adsorption chromatography, partition chromatography involves the separation of sample molecules owing to their different partition coefficients between the liquid stationary and mobile phases. The liquid stationary phase is located in the pores of a sorbent, ideally only acting as a support, making no contribution to the retention of the sample molecules. [Pg.54]

In eontrast to straight phase adsorption ehromatography, in the partition ehro-matographie mode the influence of the gas phase is less important. [Pg.54]

In prineiple, the bulk silica sorbents and the preeoated plates for partition PLC are the same types as those used in straight phase adsorption ehromatography (see Table... [Pg.54]

Aluminum oxides, similar to silica gels, are available as bulk materials and as precoated plates, to be used not only for straight phase adsorption chromatography, but also for partition PLC (see Table 3.3 and Table 3.4). In particular, the aluminum oxide type 150 (i.e., mean pore diameter 150 A [15 tun]) is suitable for partition chromatographic purposes. [Pg.55]

Liquid-solid chromatography (LSC), sometimes referred to as normal phase or straight phase chromatography, is characterized by the use of an inorganic adsorbent or chemically bonded stationary phase with polar functional groups and a nonaqueous mobile phase... [Pg.705]

Satisfactory procedures have been accomplished both on straight phase (silica gel) and on reversed phase (octadecylsilanised silica gel) columns. [Pg.73]

Module 3, Column and Mobile Phase Design (CMP). This is the core module for ECAT. It can currently specify i) analytical column and mobile phase constituents for reverse phase chromatography of common classes of organic molecules ii) reverse phase, ion exchange phase and hydrophobic interaction chromatography of proteins and peptides iii) a limited set of specialty classes of molecules best treated by straight phase chromatography (e.g., mono- and disaccharides). The rules for selection of the HPLC detector are under development within Module 3. Some of the rules for detector mobile phase compatibility are already encoded. A set of rules for detector selection is ready but not yet encoded. [Pg.288]

In straight-phase chromatography, four commonly used solvents are ... [Pg.240]

Injections of local anaesthetics often contain low concentrations of adrenaline in order to localise the anaesthetic for a time by constricting blood vessels in the vicinity of the injection. Adrenaline can be analysed by straight-phase chromatography, for instance on silica gel, but this generally requires strongly basic conditions under which the catechol group in adrenaline is unstable. Adrenaline is... [Pg.264]

Typical methodologies using straight-phase adsorbents... [Pg.313]

BASIC PROTOCOL 2 HPLC ANALYSIS OF REGIO- AND STEREOCONFIGURATION OF PRODUCTS In order to thoroughly characterize the LOX of interest, an optional procedure is offered to determine the regio- and stereospecificity of oxidation. For this purpose a reaction volume is used that is somewhat larger than that described in Basic Protocol 1 and the Alternate Protocol. The product hydroperoxides are reduced to their corresponding hydroxides, purified by TLC, methyl esterified, and separated by straight-phase HPLC followed by chiral-phase HPLC. In this way a complete structural analysis is obtained. [Pg.408]

Standard straight-phase HPLC (SP-HPLC) column (e.g., 5 pm silica, 4.6 x 250 mm e.g., Rainin)... [Pg.409]

See other pages where Straight-phase is mentioned: [Pg.91]    [Pg.394]    [Pg.42]    [Pg.44]    [Pg.52]    [Pg.284]    [Pg.284]    [Pg.127]    [Pg.213]    [Pg.239]    [Pg.240]    [Pg.243]    [Pg.265]    [Pg.247]    [Pg.202]    [Pg.604]    [Pg.404]   


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