June 11, 2015, 715004754 Rev. A
Page 111
7.3.3 Poor peak resolution
Before you address peak resolution problems, ensure that peaks elute at the correct
retention time. The most common causes of poor peak resolution can also cause
retention time problems.
If peak retention times are correct, determine whether poor resolution occurs
throughout the chromatogram or at a single peak pair.
If efficiency of early peaks is poor, extra-column band broadening, such as auto
injector or guard column failure, can be the cause. If peak efficiency is poor
throughout the chromatogram, post-column band-broadening or loss of column
efficiency can be the cause.
If only one peak in a chromatogram is badly-shaped, the peak component can be
interacting with the column through a chemical mechanism that does not affect the
components in the other peaks. Troubleshooting this resolution problem requires an
understanding of the separation chemistry.
Refer to the following table to troubleshoot peak resolution problems that affect your
results.
Reproducibility errors Solvent not properly
degassed
Degas solvent (see
“Solvent degassing
methods” on page 60).
Incorrect chemistry or
integration
Correct, as necessary.
Column not equilibrated Equilibrate column.
Injector problem Troubleshoot injector.
Table 7–4: Troubleshooting problems with retention times (continued)
Symptom Possible cause Corrective action
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