HELP: phospholipids adsorbed in my column -liposome analysis

[davidbautistaqf]

Hello everyone.
First of all, I apologize for my English, it is not my first language.

I am making liposomes encapsulating hydrophobic compounds. I am going to analize them in HPLC-UV. Since it is very difficult to separate the hydrophobic compounds from the matrix (in this case, phospholipids), we are going to inject them as a whole thing and then clean the column. Phospholipids are reported to be veeery contaminant to C18 reverse columns because of their high affinity to this phase. So I want to be sure that I have a good cleaning procedure in order to preserve my column and also for guarantee that my retention times don't change a lot between analysis.
I have found that I can clean my column with a step process in this way:

1. 100% metOH compatible with mobil phase.
2. 100% acetonitrile
3. 75:25 Acetonitrile:IPA
4. 100% IPA
5. 100% methylene chloride
6. 100% hexane

What do you think?
Also I am not sure if phospholipids are ion-pairing agents, and this is important because if they really are I guess I have to choose another method.
Thanks a lot!

PD: how do you analyse liposomes?

[Gerhard Kratz]

I would highly recommend to use SPE solid phase extraction as a first cleaning step BEFORE you inject your samples on an analytical column.

[davidbautistaqf]

Hello Gerhard, thanks for your answer.
We wanted to use SPE or SLE but we don't know if our sustances may be also retained with the phospholipids. Because this is a very first assay, we don't want to put lots of efforts in making complicated analytical process and recovery analysis. But thanks, I am going to look up that option.