The capillary inlet system is designed for capillary columns. The volume that can be injected into the column is limited to approximately 2 microliters (µL) and typically is used for pesticide and PCB analysis. The system has less column bleed and retention time shift. The packed inlet system is designed mainly for packed, wide-bore columns. However, an adapter can be used to enable capillary columns to be used. The system is used mainly for volatile analysis using a headspace extraction technique and allows a larger volume of gas to be loaded onto the GC for analysis. The split technique is the most common. The column flow is split at the injector. The technique is used for high concentration samples. The splitless technique is used for trace level analysis. The on-column technique does not involve vaporization, but instead the sample is deposited directly into the column with a syringe. This technique provides the optimum in capillary column performance by eliminating discrimination and degradation effects that can result from using a vaporization technique. The technique is well suited for high boiling point compounds. Packed column injectors that have been converted to accept megabore capillary columns (0.45 and 0.53 millimeter inner diameter) are very simple and relatively trouble free. Larger volume injections of up to 6 µL can be tolerated