ACE column peak shape problem elimination table

Possible cause

Preventive measures / solutions

Peak tail

Interaction with reactive silanols

1. Ultra-high purity silicon-based (silica gel matrix) stationary phase

2. Add alkaline mobile phase additives (such as TEA) - ultra high purity phase is not required

Chelation with metal ions in the stationary phase

Ibid.

Wrong mobile phase pH (improper mobile phase pH)

1. Reduce the pH of the mobile phase to inhibit silanol ionization

2. Increase buffer concentration

Glass frit blocking (screen plate blockage)

1. Inverted column (reverse column)

2. Use a tandem (online) filter

Invalid column (column failure)

1. Inverted column (reverse column)

2. Replacement column (column)

Dead volume not cleaned (too large)

1. Minimize the number of connectors

2. Use a shorter connecting tube

3. Check that all accessories are tight

Split peak

Pollution column or injection column inlet (injection) end contamination

1. Remove the guard column ferrule (removing the guard core) and perform analysis - replace the guard column if necessary

2. Backflushing (reverse) analytical column

3. For stubborn residues (strongly retained contaminants), try regeneration (regeneration of the column)

4. Replacement column

Glass frit blocking (screen plate blockage)

1. Inverted column (reverse column)

2. Use a tandem (online) filter

Sample solvent is not compatible with mobile phase

1. Inject the sample into the mobile phase (dissolve the sample with the mobile phase)

Elution of the second component

1. Use sample cleaning before injection (purify sample before injection)

2. Change selectivity by changing the mobile phase or column phase (column phase)

Column overload (column overload)

1. Use a higher capacity stationary phase

2. Increase the diameter of the column (increase the inside diameter of the column)

3. Reduce the amount of sample (sample)

Tongue peak

Formation of channels in the column (channels formed in the column)

1. Replacement column (column)

2. Operate within the recommended pH range of the column (recommended by the column)

Column overload (column overload)

1. Inject smaller or more diluted sample solutions (reduced injection volume or further diluted sample)

2. Use a higher capacity stationary phase

Sample solvent is not compatible with mobile phase

1. Inject the sample into the mobile phase (dissolve the sample with the mobile phase)

Low temperature

1. Increase the temperature of the column (increasing the column temperature)