The Post-sample Plug plug can be either pure organic or a mixture of organic and water.
It provides a higher transport capacity of sample through the tubing to the injector valve for cases where the polarity of the analytes and of the loop content, which is based on the start gradient, do not match. In addition, highly concentrated samples require the use of post-sample plugs because of their elevated transport capacity.
Segmentation provides increased transport efficiency and ensures quantitative sample transfer from the needle tip to the injector valve. It further minimizes risks of precipitation for samples of high concentration.