Conically shaped chromatographic column

We investigated a column with varying physical properties. A change in velo city was induced by a continuously varying the diameter inside the column. Analytical dimensions of the column were used. The diameter was continuousl y reduced from the analytical one (4.0 mm) to a diameter typical for narrow -bore columns (2.5 mm). Our interest was focused on the efficiency of a con ical column and on the mobile phase velocity in it. The results obtained wi th the conical column were compared to those obtained with the conventional analytical column and the narrow column. The diameter of the narrow column (3.3 mm) was the same as the average diameter of the conical column. The a dvantage of the conical column over the narrow column was the greater loada bility of the conical column and better dynamic efficiency. Compared to the conventional analytical column, a higher linear velocity at the same flow rate was achieved. Therefore, the retention times were shorter and consumpt ion of the mobile phase was smaller.