Phospholipids present a challenge for Chromatographers for various reasons. Here some points to consider.

  1. They have negligible UV Absorption and generally require other detection methods.
  2. Subtle structural differences among Phospholipids often lead to poor Selectivity or co-elution.
  3. For detection, Refractive Index (RI), Charged Aerosol Detection (CAD), ELSD (Evaporative Light Scattering Detection), or other “universal detectors” are recommended.
  4. As for the Separation, Organic Normal Phase (ONP) using non Polar Solvents and a Cogent Silica-C™ Column has been observed to produce excellent Resolution. 

ONP is also considered the most suitable separation mode due to the solubility of phospholipids in NP solvents like chloroform. These compounds are not water-soluble and therefore they may not be suited to ANP methods on this basis. On the other hand, their ionized / ionizable groups are amenable to ANP retention. In this case, the Cogent Diamond Hydride™ column would be best to use.