In order to prevent possible oxidation of the TRIM, a reducing agent such as 2-mercaptoethanol, ascorbic acid, dithiothreitol, and the like can optionally be employed in the sufficiently polar liquid extractant at concentration levels of from up to about 10 millimolar (mM), preferably about 1 mM. The composition containing the sufficiently polar liquid extractant and TRIM can, desirably, be subjec