Top 10 Misunderstandings of HPLC and UHPLC Columns(part 1)
1. Air completely destroys an HPLC column
When the column is not connected to the chromatograph, the user needs to ensure that the column is tightly sealed. In fact, the actual application is that even if the end of the column enters a small amount of air, it does not matter. Because when you connect the column to the chromatograph, the air is washed away by solvent in a short period of time during the initial pressurization of the system.
2. All C18 (L1) columns are the same
The USP has developed a classification system to classify each type of bonded phase column. Because the C18 column is a widely used column, the system calls it “L1.” Unfortunately, there are more than 800 L1s in the market, so it turns out that this system is unreliable and a confusing system.
3. Reverse phase column cannot use pure water phase
This misunderstanding is actually caused by the fact that some users use the low organic solvent content or pure water as the mobile phase of the reversed-phase column, which is commonly known as phase collapse. Therefore, it is considered that the reverse phase column cannot use the pure water phase. Many chromatographers are plagued by phase collapse and retention time shifts, and have even lost the patience of trying to find a solution. Therefore, they simply believe that a mobile phase with a high water content should not be run in a reversed-phase column. However, in fact, commercially available reversed-phase columns (such as polar-embedded and polar-terminated columns) are water-wetting, and their surface characteristics allow the use of pure water without causing collapse or retention time shift.