Feasibility study of gel filtration as a separation method for blood serum proteins in combination with PIXE analysis.

The combination between a protein separation technique and the PIXE method has a great potential for large surveys, including thousands of samples, in which multielemental analysis is required. Gel filtration with a Sephadex G-200 gel and a TRIS-acetate buffer was used for separating proteins in human serum. The fractions were doped with an yttrium/vanadium standard and then concentrated and pipeted onto Kimfol(™) backing foils. Using the PIXE technique, the distributions of Fe, Cu, Zn, and Se, with respect to molecular size, were found, indicating binding to specific proteins. Sulfur and phosphorus were found to correlate well with the protein content measured by UV-absorption at 280 nm. Further developments and tests on the protein separation technique is required, taking restrictions imposed by the PIXE method into consideration.