Glass capillary columns, wide-bore

Direct injection is used with wide bore capillary columns ( 0.32 mm) operated at relatively high flow rates of 5-15 ml min The injector consists of a thermostatted hot vaporization chamber with a direct connection between the liner and the column. Figure 4. Typically, a double gooseneck liner is used with the column fixed to the constriction at the bottom end (the seal is usually made between the poly-imide outer coating of the column and the inner glass surface of the liner). Using a liner with a single... 

Because of the variety of columns and samples that can be analyzed by GC, several injection techniques have been developed. The packed inlet system is designed mainly for packed and wide-bore columns. However, an adapter can be used to enable capillary columns to be used. When injection is carried out in the on-column mode, glass wool can be used for packing the injector. For capillary GC, spht technique is most common, which is used for high concentration samples. This technique allows injection of samples virtually independent of the selection of solvent, at any column temperature, with httle risk of band broadening or disturbing solvent effects. The sphtless technique, on the other hand, is used for trace level analysis. The so-called cold injection techniques (on-column, temperature programed vaporization, cooled needle split) have also been recently developed. " " ... 

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