Discrimination in injection techniques

Discrimination results from selective sample evaporation from the syringe needle. The solvent and more
volatile sample components distill from the syringe needle at a greater rate than the less
volatile  components. Consequently, the sample reaching the column is not identical in
composition with the original sample solution; it contains more of the most volatile and
less of the least volatile components of the sample.[1]
[1] Essence of Chromatography Pool C, 187