Sample introduction device:

Sample introduction into a liquid chromatography column is a very important factor in obtaining high column performance. The sample should be introduced as an infinitely narrow band on to the chromatographic bed. The more defused is the plug of sample in the mobile phase introduced into the column, the wider is the separated component bands at the end of the column. The sample is injected with a micro-syringe through a septum contained in a low volume inlet system. Septum materials are generally made from silicone or Neoprene. It is generally not feasible to make syringe injections above about 1500 psi through sampling ports. Therefore, at high pressure, a stop flow injection technique is normally used with syringe.