Chromatography batch operation

The corresponding batch operation protocol refers to the following procedure [8], The 1,3-dicarbonyl compoimd (0.25-0.50 g 1.5-5.0 mmol) was added to a stirred solution of ethyl propiolate (0.15-0.49 g 1.54—5.0 mmol) and diisopropylefhylamine (0.40-1.29 g 3.00-10.00 mmol) in ethanol (50 ml). After stirring overnight, the reaction mixture was concentrated and purified by silica gel chromatography. 

A number of operating parameters in batch chromatography result from the batch operation mode switch times... 

The commonly used elution and displacement chromatography process techniques use batch operation, wherein a pulse of the mixture to be separated is... 

At the current time, there is considerable interest in the preparative applications of liquid chromatography. In order to enhance the chromatographic process, attention is now focused on the choice of the operating mode [22]. SMB offers an alternative to classical processes (batch elution chromatography) in order to minimize solvent consumption and to maximize productivity where expensive stationary phases are used. 

The three main modes of chromatographic operation are elution chromatography, selective adsorption/desorption, and simulated countercurrent chromatography. Of these, elution chromatography, used as a cyclic batch process, was the first to be developed for large-scale separations. 

In this chapter we focus primarily on calibration of LC-MS where the mass spectrometer is operating at unit resolution, resolution that is sufficient to separate two peaks one mass unit apart. This kind of low-resolution mass filter covers almost 90 percent of the instruments commonly used for qualitative and/or quantitative analysis of small molecules. Batch-to-batch qualification testing of the instrument is also described. For the calibration of high-resolution mass spectrometers such as magnetic sector, TOF, or FTICR coupled with liquid chromatography, readers are referred to specific publications. 

Batch processing appears as one of the simplest ways to use chromatography. This process uses one column and operates in a succession of injections (at the inlet of the column) and collections (at the outlet of the column). The eluent consumption is the ratio of the volume of eluent used divided by the amount of product purified. Reduction of the eluent consumption can be achieved by, for example, increasing the injected amount or reducing the cycle time [12]. 

Notes. (1) Warming the suspended solid in the solvent may be necessary by removing the porridge to a suitable flask and heating under reflux. Care must be taken if such is the case to supervise this operation carefully as there may be considerable tendency towards bumping . It should also be borne in mind that this batch-extraction process uses open-type vessels and usually large volumes of solvents precautions must therefore be taken in relation to the possible fire and toxic hazards involved in the use of a particular solvent. (2) As a first step, this procedure would involve solvent extraction procedures to divide the multicomponent mixture into acidic, basic and neutral fractions (see above). Subsequently chromatography, fractional crystallisation, etc., would be employed as appropriate. 

As the ligand-protein interaction takes place at the internal surface of porous adsorbents, kinetics and equilibrium of the interaction should be independent of the interstitial voidage within an adsorbent bed. Therefore the equilibrium capacity of an adsorbent will not be influenced by different experimental configurations e.g. batch stirred tank, batch fluidized bed, frontal application to packed or fluidized beds. The major difference arises from the medium from which the protein is isolated. As fluidized beds are used for whole broth adsorption, the properties of the broth have to be considered regarding the possible influence of components which are removed in conventional primary recovery steps and therefore are not present during the initial chromatography operations in a standard downstream process. These are on one hand nucleic... 

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