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Chromatographic elution

An example of the results obtained in the form of a chromatoelectropherogram can be seen in Figure 9.6. The contour type data display showed the three variables that were studied, namely chromatographic elution time, electrophoretic migration time, and relative absorbance intensity. Peptides were cleanly resolved by using this two-dimensional method. Neither method alone could have separated the analytes under the same conditions. The most notable feature of this early system was that (presumably) all of the sample components from the first dimension were analyzed by the second dimension, which made this a truly comprehensive multidimensional technique. [Pg.205]

Each of the three approaches will be applied in this section to the transformed retention times of the 23 chalcones with eight chromatographic elution methods in Table 31.2. The transformation is defined by the successive operations of logarithms, double-centering and global normalization which is typical for the method of spectral map analysis (SMA) ... [Pg.142]

The narrow range of organic modifiers required to elute and desorb polypeptides from the reversed-phase column packing material accounts for the separation of polypeptides from a short C18 capillary column. Because polypeptide elution and separation depend on the accuracy of solvent composition in gradient nano LC, it is very important to use a system that can precisely control the LC modifier concentration even at low percents of organic modifiers in chromatographic elution compositions. [Pg.361]

The various, theoretically derived relationships between gel-chromatographic elution-parameters of macromolecules and their molecular weights are given in Table V. [Pg.24]

The following mathematical descriptionof the development of a chromatographic elution profile assumes that the vapor is in equilibrium with the adsorbent, that diffusion is absent or of negligible rate compared to the flow rate, and that the adsorbent is uniformly packed in the column. [Pg.185]

The usual basis of predictions of migratory behavior of ions in geological strata is the treatment of this behavior as an equilibrium chromatographic elution (], 2). This then leads to the following expression for the migratory velocity (v) of a species ... [Pg.191]

Very high sensitivity (to ppt) can be obtained with compounds that are extractable by SDE. However, highly water-soluble compounds are not extracted completely and compounds with very low boiling points, such as methanethiol, can be lost during concentration. In addition, compounds with gas chromatographic elutions simultaneously with the solvent are hidden from view. Quantification can be made by addition of an internal standard to the sample matrix. [Pg.1010]

AG Lynch, DM Mulvihill, AJR Law, J Leaver, DS Horne. Chromatographic elution profiles, electrophoretic properties and free amino and sulphydryl group contents of commercial sodium caseinates. Int Dairy J 7 213-220, 1997. [Pg.162]

R Pecina, G Bonn, E Burtscher, O Bobleter. High-performance liquid chromatographic elution behavior of alcohols, aldehydes, ketones, organic acids and carbohydrates on a strong cation-exchange stationary phase. J Chromatogr 287 245-258, 1984. [Pg.318]

To a solution of the S-(+)-4-acethoxy-9-[2-(5-ethyl-l,2,3,6-tetrahydro-pyridin-3yl)-l-(lH-indol-2-yl)-l-methoxycarbonyl-ethyl]-3a-ethyl-5-hydroxy-8-methoxy-6-methyl-3a,4,5,5a,6,ll,12,12b-octahydro-lH-6,12a-diaza-indeno[7,l-ca]fluorene-5-carboxylic acid methyl ester in dioxane and glacial acetic acid was added 37% aqueous formaldehyde and the mixture stirred at 35°C for 24 h. The solution was evaporated in vacuo and the residue suspended in chloroform and washed with cold aqueous 5% K2C03 solution. The chloroform layer was dried (MgS04), filtered, and evaporated. The residue was chromatographed eluting with EtOAc/MeOH, 10% NH4OH to give the product navelbine. [Pg.3444]

Programmed analysis can be defined as a chromatographic elution during which the operation conditions are varied. The parameters that may be varied during the analysis include temperature, mobile phase composition and flow rate. [Pg.253]

The situation in programmed analysis is similar to the one described above for chromatographic elution under constant conditions, in that retention and selectivity may be optimized more or less independently. However, under constant elution conditions the optimization of the retention only involves adapting the primary parameters such that all capacity factors fall into the optimum range (1 programmed analysis the optimization of the retention involves optimizing the characteristics of the program (initial and final composition, slope and shape) in conjunction with the physical parameters (e.g. flow rate and column dimensions, see section 3.6). [Pg.267]


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Analysis of Chromatographic Elution Curves

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Gradient elution liquid chromatograph

Plate Theory Equation for Chromatographic Elution

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