Revision of Analytical Conditions for Determining Ligand Molecules Specific to Soft Metal Ions Using Dequenching of Copper(I)-Bathocuproine Disulfonate as a Detection System

Reoptimization of analytical conditions was performed for a high-performance liquid chromatographic (HPLC) detection system for Cu(I) chelators based on the dequenching of Cu(I) bathocuproine disulfonate complexes that occurs in the presence of Cu(I) chelators. The revision corrects for emission and excitation wavelengths that were in fact second-order light of the actual optimal wavelengths and for the composition of the postcolumn solution. These revisions resulted in an order of magnitude decrease in detection limits of phytochelatins, a class of cysteine-rich, heavy metal-binding peptides. The revised technique is capable of phytochelatin quantitation at femtomole quantities.