Cleaning Lipid Contamination with Organic Solvents (HPLC)

[melcron]

I am currently using a Agilent Technologies 1200 Series HPLC with an RPC column, which was previously used for analyzing organic compounds containing high concentrations of lipids. I am getting a lot of noise in my analysis even after the standard wash procedures. The solvents used in my HPLC are (Solution A) 5%ACN/95%H20 and (Solution B) 95%ACN/5%H20.

I am currently replacing Solution B with 95% dichloromethane but this does not seem effective so far.

Any recommendations?

[Consumer Products Guy]

If you replace the column with capillary tubing: is the noise better, worse, or the same? That should tell you a lot.

[tom jupille]

A bit more detail would be useful:

is your method isocratic or gradient?
what detector? if UV, what wavelength?
is the noise "random", or is there a pattern to it?
do you get the same noise pattern when you inject a blank?
if random, is the noise higher or lower under no-flow conditions?