A STUDY OF DEPROTEINIZATION METHODS FOR SUBSEQUENT SERUM ANALYSIS WITH CAPILLARY ELECTROPHORESIS

Fifteen different methods of serum protein removal are examined for ap plicability with subsequent serum analysis for low molecular mass meta bolites and pharmaceutical agents by capillary electrophoresis (CE). E ach of the deproteinization methods considered here has been reported in the literature and successfully used for serum protein removal in o ther applications. Two of the methods are found to be superior to the others for CE analysis. Protein removal by ultrafiltration with Centri free Micropartition System filters and by precipitation using acetonit rile worked well for protein removal, as evidenced by reproducible (RS D <6%) determinations of several low molecular weight components. The former is capable of analyzing for free metabolites only, while the la tter was found to be somewhat problematic with respect to evaporation of the acetonitrile, causing potential problems with reproducibility. Both techniques for protein removal were clearly suitable for the subs equent serum analysis by CE in untreated fused silica capillaries. (C) 1997 Academic Press.