Peak Tailing Causes and Solutions

Cause Solution

Basic solutes - silanol interactions Use competing base such as triethylamine; use a stronger mobile phase; use base-deactivated silica-based reversed-phase column; use polymeric column

Beginning of peak doubling See peak doubling

Chelating solutes - trace metals in base silica Use high purity silica-based column with low trace-metal content; add EDTA or chelating compound to mobile phase; use polymeric column

Silica-based column - degradation at high pH Use polymeric, sterically protected, or high-coverage reversed-phase column; install silica gel saturatorcolumn between pump and injector

Silica-based column - degradation at high temperature Reduce temperature to less than 50 C

Silica-based column - silanol interactions Decrease mobile-phase pH to suppress silanol ionization; increase buffer concentration; derivatize solute to change polar interactions

Unswept dead volume Minimize number of connections; ensure injector rotor seal is tight; ensure all compression fittings arecorrectly seated

Void formation at head of column Replace column, or, if possible, open top endfitting and clean and fill in void with glass beads or samecolumn packing; rotate injection valve quickly; use injection valve with pressure bypass; avoid pressure shock

Basic solutes - silanol interactions	Use competing base such as triethylamine; use a stronger mobile phase; use base-deactivated silica-based reversed-phase column; use polymeric column
Beginning of peak doubling	See peak doubling

Chelating solutes - trace metals in base silica	Use high purity silica-based column with low trace-metal content; add EDTA or chelating compound to mobile phase; use polymeric column
Silica-based column - degradation at high pH	Use polymeric, sterically protected, or high-coverage reversed-phase column; install silica gel saturatorcolumn between pump and injector
Silica-based column - degradation at high temperature	Reduce temperature to less than 50 C
Silica-based column - silanol interactions	Decrease mobile-phase pH to suppress silanol ionization; increase buffer concentration; derivatize solute to change polar interactions
Unswept dead volume	Minimize number of connections; ensure injector rotor seal is tight; ensure all compression fittings arecorrectly seated
Void formation at head of column	Replace column, or, if possible, open top endfitting and clean and fill in void with glass beads or samecolumn packing; rotate injection valve quickly; use injection valve with pressure bypass; avoid pressure shock