Use of HPLC Columns
Before using the HPLC columns, it is best to test the performance of the column and save the results as a reference for future evaluation of HPLC columns performance changes. However, it should be noted that the column performance may vary depending on the conditions of the sample, mobile phase, column temperature, etc.; in addition, the column performance test is performed according to the conditions in the column factory report (factory test). The conditions are the best conditions), and only then, the measured results are comparable.
1. Pretreatment of the sample:
a. It is best to use a mobile phase to dissolve the sample.
b. Use a pretreatment column to remove strong polarities in the sample or impurities that irreversibly adsorb with the column packing.
c. Use a 0.45 um filter membrane to remove particulate impurities.
2. Selection of mobile phase flow rate:
Since the column efficiency is a function of the linear flow rate of the mobile phase in the HPLC columns, different column rates can be obtained using different flow rates. For the best column performance for a particular column, it is best to use the optimum flow rate. For a column with an inner diameter of 4.6 mm, the flow rate is generally selected to be 1 ml/min, and for a column having an inner diameter of 4.0 mm, a flow rate of 0.8 ml/min is preferred.
When the optimum flow rate is selected, the analysis time may be extended. A method of changing the washing strength of the mobile phase can be employed to shorten the analysis time (for example, when a reverse phase HPLC column is used, the content of methanol or acetonitrile can be appropriately increased).