Rut this is time- and analyst intensive and analytical laboratories are all about efficiency Sothisis where the split/splitless injector come in Using merely a flick of a software-controlled valve the amount of injected analyte can be instantly varied before an injection is made. This is called the split ratio and is a function ofthe ratio of gas flows through the GC's injector, all controlled by pressure gas flows in the injector W at wait it get better. In older instruments this was carried out by manual control of gas valves. By in modem GOs this all controlled by software and can be stored in the analytical method Butintensive