What can I do about baseline drift with my LC method?

• Ensure column has been fully equilibrated if changing mobile phase; run 10-20 column volumes of new mobile phase before analysis.
  
  
• Small changes in temperature can cause cyclic baseline rise and fall.  This is more common with RI and conductivity detectors. Use a heat exchange pre-column to control temperature.
  
  
• Nonhomogenous mobile phase typically cause upward baseline drift. Mobile phase may be contaminated, deteriorated, or prepared from low quality materials.
  
  
• Contaminants in detector cell may cause drift; clean with strong solvent or passivate.
  
  
• If strongly retained compounds are eluting, this can appear as broad peaks in subsequent injections which appear to be rising baseline.
  
  
• Ensure the line after detector is not plugged, as high pressure cracks in flow cell window may produce noisy baseline.