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Troubleshooting Problems with Peak Shape

Peak Tailing

Possible Cause

Prevention/Solution

Interaction with active silanols

Use ultra-high purity silica-based stationary phase

Add basic mobile phase additive (eg. TEA)

– not needed with ultra-high purity phases

Chelation with metal ions in stationary phase

Use ultra-high purity silica-based stationary phase

Add basic mobile phase additive (eg. TEA)

– not needed with ultra-high purity phases

Wrong mobile phase pH

Decrease mobile phase pH to suppress

silanol ionization

Increase buffer concentration.

Blocked frit

Reverse flush the column

Use in-line filter

Column void

Reverse flush the column

Replace the column

Unswept dead volume

Minimize the number of connections

Use shorter connection tubing

Check all fittings are tight



Split Peaks

Possible Cause

Prevention/Solution

Contamination on guard or analytical column inlet

Remove guard cartridge and carry out analysis – replace guard if necessary

The reverse flush analytical column

For strongly retained contaminants, try the regeneration procedure

Replace column

Blocked frit

Reverse flush the column

Use in-line filter

Sample solvent incompatible with the mobile phase

Inject sample in the mobile phase

Simultaneous elution of the second component

Use sample clean-up prior to injection

Change selectivity by changing mobile phase or column phase

Column overloaded

Use higher capacity stationary phase

Increase column diameter

Decrease sample amount



Peak Fronting

Possible Cause

Prevention/Solution

Formation of channels in column

Replace the column

Operate within recommended pH limits of the column

Column overloaded

Inject a smaller volume or more dilute sample solution

Use higher capacity stationary phase

Sample solvent incompatible with the mobile phase

Inject sample in the mobile phase

Low temperature

Increase column temperature



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