F.A.Q.

Peak tailing can occur due to numerous reasons. The problem can be identified according to the following scheme:

• Mass overload: when injecting less sample amount (mass) either the peak becomes more symmetrical or resolves into two separate peaks.
  Corrective action: use a more dilute injection sample.
• Secondary interactions: when injecting a neutral compound (acetophenone, toluene) the peak becomes symmetrical
  Corrective action: adjust the mobile phase pH in order to render neutral analytes.

For larger ID columns (>10 mm) radial temperature gradient can also cause peak tailing. In order to avoid such, it is recommended to use a column oven. The column should be 1-2°C warmer than the mobile phase in order to compensate for the friction heat generated in the core of the column.

If neither of the above applies, the tailing can also be caused by irregularities in the column packing process or by a partially clogged inlet frit leading to an inhomogeneous flow profile.