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.