PTV On-Column Injection

A regular PTV injector can also be used successfully for on-column injections. This method allows the straightforward automation of on-column injections using regular autosamplers with standard syringes. The insert liner used needs to be equipped with a restrictor at the top. This restrictor functions as a needle 

In PTV on-column mode, the injector body and the column oven is set for injection to a temperature below the solvent boiling point (see Table 2.23). After a short injection time of up to 20 s the injector is heated up for sample transfer. The oven program is started right after the completed sample transfer into the analytical column. The split valve remains opened with a low flow rate of only a few millilitre per minute. The PTV temperature is maintained high throughout the chromatographic run as usual. 

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