Columns Snyder

The sorbant trapping process in purge and trap analysis is essentially a concentration step, but combined with cryogenic focusing this affords better injection on to the chromatography column and loss of very volatile substances, e.g. vinyl chloride which may not be trapped on the absorbant. 

Snyder columns are designed to allow highly volatile solvents to escape whilst retaining the semi-volatile compounds of interest. They are normally fitted onto the top of flasks containing extracts. The flasks may be heated, the design of the column allows volatile solvent to escape during the process. The analytes of interest condense from a vapour to a liquid phase and are collected in the solvent reservoir. 

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Snyder column Kudema Danish concentrator Nitrogen evaporation Vacuum... 

Glassware. All special borosilicate glassware was fabricated in-house. Kudema-Danish (K-D) evaporators and the modified Snyder columns were constructed as per the design described previously (25) adsorption glass... 

Each of these six organic fractions was reduced to a volume of about 5 mL in a Kudema-Danish concentrator under a three-ball Snyder column and then to a volume of 1.0 mL under a gentle stream of dry nitrogen. These concentrates, or their methylated derivatives adjusted to the same concentration, were analyzed as described in the next section. 

After drying (removal of water), the extract is quantitatively transferred into a Kudema-Danish flask equipped with a concentrator tube and a Snyder column for sample concentration. The apparatus is placed in a water bath and ether is evaporated out. Use boiling chips in all heating operations. The volume of the extract is concentrated down to 1 to 2 mL. 

Add one or two clean boiling chips to the round bottom flask from the SDS exeractor or the reflux flask. Attach a three-ball macro Snyder column. 

J. Gilroy, J. Dolan, and L. Snyder, Column selectivity in reversed-phase liquid chromatography IV.Type-B alkyl silica columns,/. Chromatogr. A1000 (2003),757-778. 

The K-D concentrator is a Snyder column with a removable collection tube attached to the bottom. As the solvent is evaporated, the extract is collected in the collection tube. 

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