Video-taped sample evaporation in hot chambers simulating gas chromatography split/splitless injectors. I. Thermospray injection.
The processes in devices imitating vaporising injectors were visualised and video-taped using perylene as a fluorescent marker for non-evaporated samples. The observations in the context of thermospray injection are summarised. Partial evaporation inside the needle turns the solvent into a propellant which nebulises the sample liquid at the needle exit. Evaporation in the vaporising chamber occurs from fine droplets suspended in the gas phase. Empty injector liners are best suited; packings with glass wool or obstacles in the liner, like the cup, have no significant effect on the process observed. Non-evaporated (matrix) material forms aerosol particles which may enter the column together with the vapours, but most of them are transferred to the liner wall. Since solute material may be carried along, this is a possible source of matrix effects.
Sample evaporation in conventional split/splitless GC injectors: Part 2: Use of perylene for visual observation of three different scenarios in empty injector inserts
Perylene is strongly fluorescent as long as it is in solution. This has enabled visual observation of non-evaporated sample material in a “transparent injector”, i.e. in a heated glass device imitating a conventional vaporizing injector. 
 
 
 
Three scenarios of sample evaporation are described. Some samples (solvents) are nebulized and “flash evaporated” in the gas phase between the needle exit and the column entrance (Scenario 1). With most solvents, the liquid leaves the syringe needle as a thin jet which rushes through both the empty vaporizing chamber and the split outlet at high velocity, often without substantial evaporation. It does not touch the surfaces of the insert and passes round the bend at the bottom of the device without any problem (Scenario 2). Some samples are splashed on to the insert wall, wet it, and evaporate rather slowly from this surface (Scenario 3).
Optimized injection for determination of free phenols by gas chromatography using fused silica columns
Optimisation des conditions d'injection, en particulier, de la temperature de la chambre d'injection