First, I don't have much experience with Splitless injections. I have a method, it is splitless injection mode, the liner is 4mm ID and 78.5mm length, the column flow rate is 8ml/min, and the septum flow is 3ml/min. Is it necessary to set up the purge flow and purge time? Are the purge flow and purge time critical conditions or minor? Can these two conditions be altered during the sample analysis when the method is validated? We run the same method with the splitless on the GC model 6890, the purge flow and purge time are left blank, but the system is still working, why?