title: Deproteination of serum samples for LC-MS/MS analyses by applying magnetic micro-particles.
abstract: OBJECTIVE
  Investigation of the practicability and performance of a magnetic micro-particle based method for protein depletion of serum samples, preceding the quantitative analysis of small molecules by LC-MS/MS.
  
  
  METHODS
  A commercially available kit including a protein denaturation reagent and functionalized magnetic particles together with a magnetic separator device was tested by addressing the quantification of amiodarone in serum as an exemplary analyte by LC-MS/MS with on-line SPE. A standard method validation protocol was applied.
  
  
  RESULTS
  The sample preparation protocol was found to be convenient, straightforward and robust. Validation data characterized the entire analytical method - combining particle-based protein depletion and two-dimensional chromatography - as compatible with the analytical needs regarding selectivity, accuracy (102-106%), linearity (r(2)≥0.99), reproducibility (CV<7%), and control of ion suppression.
  
  
  CONCLUSIONS
  Since this novel approach of sample preparation does neither require centrifugation nor the technically demanding application of positive or negative pressure, as in conventional solid phase extraction protocols, it seems highly attractive for developing fully automatized preparation systems for LC-MS/MS analyzers.
authors: Institute of Laboratory Medicine, Hospital of the University of Munich, Munich, Germany. katrin.koenig@med.uni-muenchen.de
authors: Katrin
authors: K
authors: König
authors: Sven F
authors: SF
authors: Goethel
authors: Viorel M
authors: VM
authors: Rusu
authors: Michael
authors: M
authors: Vogeser
mesh_terms: D000638:Amiodarone / Q000097:blood; D057205:Automation, Laboratory / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005590:Fractional Precipitation; D006801:Humans; D008280:Magnetics; D011489:Protein Denaturation; D011506:Proteins / Q000302:isolation & purification*; D015203:Reproducibility of Results; D044967:Serum / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D011506:Proteins; D000638:Amiodarone