How to Solve the Problem of Poor Repeatability of HPLC Column?

There are three main reasons for the poor repeatability of the HPLC columns:
(1) The injection valve leaks;
(2) The sample needle is not in place.
(3) Insufficient liquid volume.

To replace the injection valve gasket for this case; for the second case, ensure that the needle is inserted to the end, and the sample solution must be quickly and smoothly switched from the LOAD state to the INJECT state to ensure the injection volume is accurate. In daily work, the maintenance of the liquid chromatograph is very important. If you are careful not to let the air enter the infusion system and the high-pressure pump, the solution in the reservoir should be cleaned and replaced with a solution if it has not been used for a long time. After the chromatograph is finished, the buffer should be rinsed with pure water to prevent precipitation or deposition of inorganic salts. The pretreatment of the sample is also important. Any sample should be removed as much as possible, completely dissolved, and the contamination of the HPLC columns should be minimized. Extend the service life of the column while avoiding the injection of the concentrated sample solution to prevent the residual liquid from clogging in the injection valve. The column is marked and the column for different analysis purposes should not be mixed.