Sigma-Aldrich Introduces Hybridspe™- Precipitation Technology
Product News Nov 14, 2008
Supelco, a division of Sigma-Aldrich, introduces a new patent pending sample prep platform called HybridSPE-Precipitation, which merges the two predominate techniques in bioanalytical sample preparation: protein precipitation and solid phase extraction (SPE).
One of the major causes of ion-suppression in bioanalysis is the presence of phospholipids during LC-MS or LC-MS-MS analysis in the positive ion electrospray mode (+ESI). Phospholipids are the second largest lipid component in biological matrices after triglycerides, and are typically present in extremely high concentrations in biological plasma samples.
HybridSPE – PPT technology is a simple and generic sample preparation platform designed for the gross level removal of endogenous protein and phospholipid interferences from biological plasma and serum prior to LC-MS or LC-MS/MS analysis.
Biological plasma or serum is first subjected to protein precipitation via the addition and mixing of acidified (with formic acid) acetonitrile. The HybridSPE 96-well plate (or cartridge) acts as a chemical filter that specifically targets the removal of endogenous sample phospholipids. The 96-well version contains a series of low porosity hydrophobic filters/frits, the packed-bed filter/frit assembly acts as a depth filter facilitating the concurrent removal of both phospholipids and precipitated proteins during the extraction process. The cartridge version requires removal of precipitated proteins prior to load on the HybridSPE bed e.g. by centrifugation.
The phospholipid retention mechanism is based on a highly selective Lewis acid-base interaction between the proprietary zirconia ions functionally bonded to the HybridSPE stationary phase and the phosphate moiety consistent with all phospholipids. The resulting eluent is ready for immediate LC-MS or LC-MS/MS analysis with out phospholipids interference.