I have analyzed a lot of lipids and fatty acids over the years. Yes, they will quickly foul up your column so washes are very important (true for all types of samples). Most phospholipids are soluble in Methylene chloride so it should be considered as a primary solvent used with something slightly more polar. Depending on which ones are present, you may wish to use a wash solution (gradient) that includes a more polar alcohol too (MeOH and/or Ethanol) as well as dimethylsulfoxide (DMSO) or chloroform. Rather than mixing a bunch of these solvents together, I prefer to run a gradient using two or three of them over time. Ramp up to high MeCl concentrations at the end, hold, then wash the column back down with a mixture of MeOH with some water in it (95/5).

If this is in the case, I will use chroloform/methanol = (1/2, v/v), subsequently chroloform/methanol= (1/1),  and chroloform/methanol = (2/1) or chlroform/methanol/water = 2/1/0.8 (v/v/v). The above solvents will be able to dissove phospholipids.

At the end in last step can use only methanol that will help if any lipids left on the column. Other experts have answered in details. 

Thank you very much for your answers. Do you know if phosphatidylcoline can affect a C18 column like in a ion-pairing contamination? Thanks.

With some lipids this can happen, but I do not think it would be a concern with Phosphatidylcholine (PC). However, most lipids are rather "dirty" so I would always label and use that column specifically with the one method/application and not use it for other methods (this is generally true with most compounds, but especially sticky ones).

Remember, columns are consumables. They have a useful lifetime after which they need to be disposed of.

Thank you Bill, you have been of so much help. I haven't started yet with the analytical procedure since de preparation of liposomes have been complicated (related to size tuning) but in the future I'm going to make some questions about this since I'm the only chemist in my group and I'm more like a biochemist and not that much analytical but I have to do all the work so it's nice to learn about this. Also I guess I'm going to try to use UV absorption since Vitamin D absorbs different from PC and cholesterol. Thanks.

Thank you for the kind words.

Lipids do not really absorb at all which is why you will only see UV/VIS methods  using 204-215nm (which detects just about everything, but with poor sensitivity and accuracy). Vitamin D; UV/VIS is no problem. As I probably stated before, we usually use ELSD or CAD for lipids (by HPLC) or derivatize them and use GC/MSD. The two are really mutually exclusive.

Obivipusly need to wash several time with methanol will elite all the lipids