chemistry

Peaks with strange shapes represent one of the most common problems that can arise in the LC/HPLC laboratory. A distortion that peaks show quite often is peak tailing. It should be first explained why tailing is bad : Peaks with tailing can be hard to integrate The precision and the reliability of assay methods involving distorted – peaks with tailing – is often poor when compared to good chromatography Resolution is low when peaks show tailing    Fig. 1: Peaks showing tailing   How do we solve the problem of tailing peaks?  We should at first consider the various general causes of peak tailing such as: Bad column Sample overload Band fronting Wrong solvent for the sample Strong retention sites (normal-phase or ion-exchange chromatography) Not enough buffering We should investigate which of the above causes create peak tailing and attempt to rule out  causes that do not seem relevant. Often it is possible to quickly rule out a potential cause of peak tailing and go to the next pos