Supelco has introduced the HybridSPE-Precipitation sample prep platform, which merges 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 present in high concentrations in biological plasma samples.
HybridSPE - PPT technology is a simple and generic sample preparation platform for 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 phospholipids and precipitated proteins during the extraction process.
The cartridge version requires removal of precipitated proteins prior to load on the HybridSPE bed, for example by centrifugation.
The phospholipid-retention mechanism is based on a 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 without phospholipids interference.
