Dehydro-L-ascorbic acid, the oxidation form of Lascorbic acid, converts nonenzymatically to a variety of transformation products depending upon the incubating conditions. These products, called the ascorbate cascade, possess different absorption spectra and reducing activities. Ion-pairing high-performance liquid chromatography with multiwavelength uv absorption and amperometric electrochemical detection has proven to be a useful technique for the analysis of these products. Separation and characterization in the present investigations reveal three kinds of transformation products: the polymerized intermediates of browning reaction, the reductant possessing an absorption maximum at 345 nm as the six-carbon compound, and erythro-L-ascorbic acid, 2 -furoic acid, 3 -hydroxy- 2 -pyrone, 5 -methyl-3,4dihydroxytetrone, reductic acid, and furfural as the five-carbon compound. These products possess an absorption maximum above (240 \mathrm{~nm}), and most of them are electrochemically active reducing compounds which are derived from nonreducing dehydro-L-ascorbic acid through the processes of delactonization, decarboxylation, and intramolecular rearrangement. (c) 1993 Academic Press, Inc.