HPLC injection is a technique to inject the sample without disturbing the flow rate and pressure of the HPLC system. The working pressure of an HPLC is adequately high that we cannot inject a sample into the mobile phase by inserting a syringe, so we need an injector that gives a reproducible result and without interrupted the flow rate and system pressure. Nowadays HPLC sample injector set in the different range of volume so you can inject the specific requires a volume.
Here are certain requirements of HPLC Injector are as follows.
1. Introduce the Sample with constant pressure and flow rate of the HPLC system
2. Introduce the sample without air bubbles
3. The injection volumes of sample are in microliter so it should be accurate
4. The sample must be free from any particulate matterThere are three types of injector are available for HPLC systems.
Rheodyne Injector: The most commonly used injector is Rheodyne, easy to use with high accuracy and precision. As per requirement, the analyst can set the volume of the sample loop. Rheodyne has two positions load and inject. The load position allows loading the sample into to loop with the help of a syringe which is commonly used to sample load into the injector. After a load of the sample, manually rotates of the sample injector to the inject position allows flowing the sample onto a column without any air bubbles, without disturbing flow rate and pressure.
Septum Injector: In this system, the sample injects through the rubber septum.
Stop flow Injector: In this type of system mobile phase stopped while the sample is injected.
