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 |
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 |
0 Comments