Problems in formulating method-insensitive proficiency testing materials.

Abstract

Significant problems exist in formulating method-insensitive proficiency materials. Many steps are required in processing human plasma, and difficult choices are involved in the selection of appropriate materials to be added to the processed plasma. Additionally, analytes may vary widely in their recovery from method to method. To enhance understanding of the procedures and problems involved in the development and manufacture of proficiency materials, a number of constituents and their method-specific recoveries are reviewed.