Peak broadening or wide peaks

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Probable cause		Suggested actions
1	Extra-column effects	Check your system for long tubing lengths between components and where possible, replace them with shorter connection lengths or capillaries with smaller internal diameters.
2	NOTE: If the capillary stem length is too short, it creates dead volume in your system.	Ensure that your fittings are made correctly
3	Column overload	Reduce the injection volume or dilute the sample. Switch to a column with a higher sample capacity (increase length or diameter).
4	Injection solvent effects	If possible, use the starting mobile phase composition or weaker solvents as the injection solvent. Ensure that the injection solvent is miscible with the mobile phase and causes no salt precipitation. Reduce the injection volume.
5	NOTE: The eluent pH and the column temperature shall never exceed the manufacturer‘s specifications. Use specialty columns when working at high temperatures and/or pH extremes. NOTE: Most silica-based columns degrade rapidly at pH below 2 or above 8, especially at temperatures higher than 40 °C.	Check the number of injections does not exceed the typical number of injections for this column and application. Replace the column if necessary.
6	Large dwell volume	If possible, reduce the dwell volume of your system. Check if the affected peak is eluted during the gradient, and not isocratically. If necessary, reduce the initial gradient composition to focus peaks.
7	Improper method settings	Check the detector method settings , such as wavelength and data rate, and optimize them if needed.
8	Worn injection valve rotor seal	Replace the rotor seal in the injection valve.
9	NOTE: Use high purity HPLC grade or better solvents only. Solvents from different suppliers might have subtle differences in their contamination profile. NOTE: The eluents should be miscible and should not form salt precipitates over the range of the entire gradient. The eluents should also be properly degassed.	Ensure that the choice of the mobile phase is appropriate for the analyte. Ensure solvent lines are associated with the desired mobile phases. If in doubt switch to a fresh batch of solvents.
10	Wrong column	Ensure that stationary phase selection is appropriate for the analyte. Ensure mobile phase and column compatibility. Ensure using columns with wider pores (≥ 300 Å) for larger molecules and smaller pores (< 300 Å) for small molecules.

21-Jun-2025