Inability of unpacked gooseneck liners to stop the sample liquid after injection with band formation (fast autosampler) into hot GC injectors

With the introduction of the fast autosampler, the rules on how to perform splitless injection should have been revisited: the fast autosampler releases the sample liquid as a band that is no longer nebulized by solvent vapors as in previous injection techniques. In empty gooseneck liners, the sample liquid is shot to the bottom of the injector and jumps around in a largely uncontrolled manner. Visual experiments showed that the liquid is partially rejected. Another portion passes by the column inlet into the column attachment region, while the last part may directly enter the column. The impact on chromatography was investigated by using a mixture of n-alkanes: the higher boiling components passing by the column entrance into the zone of the column attachment were largely lost, i.e., were discriminated against the volatile components. It was concluded that empty gooseneck liners are not suitable for injection by fast autosamplers.