Peroxyoxalic acid, peroxyoxalate chemiluminescence

Applications of the oxalate-hydrogen peroxide chemiluminescence-based and fluorescence-based assays with NDA/CN derivatives to the analysis of amino acids and peptides are included. The sensitivity of the chemiluminescence and fluorescence methods is compared for several analytes. In general, peroxyoxalate chemiluminescence-based methods are 10 to 100 times more sensitive than their fluorescence-based counterparts. The chief limitation of chemiluminescence is that chemical excitation of the fluorophore apparently depends on its structure and oxidation potential. 

Grayeski, M.L., and DeVasto, J.K. (1987) Coumarin derivatizing agents for carboxylic acid detection using peroxyoxalate chemiluminescence with liquid chromatography. Anal. Chem. 59, 1203. 

Mansouri A, Makris DP and Kefalas P. 2005. Determination of hydrogen peroxide scavenging activity of cinnamic and benzoic acids employing a highly sensitive peroxyoxalate chemiluminescence-based assay structure-activity relationships. J Pharm Biomed Anal 39(l-2) 22-26. 

This brief summary of peroxyoxalate chemiluminescence in no way does justice to the topic and the interested reader is urged to consult the more comprehensive accounts cited in this chapter. If and when water-soluble oxalate esters become readily available, there is no doubt that these labels will be adapted to the types of assay that have formed the main subject matter for this article, viz., immunoassays, nucleic acid and gene probe assays, and clinical chemistry assays. 

Used as derivatising agent for carboxylic acid detn., using peroxyoxalate chemiluminescence in liquid chromatography. Yellow needles. Mp 215-216° dec. 

Labelling reagent for carboxylic acids in liq. chromatog. with peroxyoxalate chemiluminescence detection. 

This chemiluminescent reaction was suggested as occuring via ring opening of the cyclic carbonate group with subsequent ring closure to the peroxide (2). An alternative is formation of the diperoxy acid (3). Although a relationship to oxalyl chloride and peroxyoxalate chemiluminescence seems reasonable, details of the excitation step are not known. 

The brilliant emissions resulting from the oxidation of certain oxalic acid derivatives, especially in the presence of a variety of fluorophores, are the bases of the most active area of current interest in CL. This group of chemiluminescent reactions has been classified as peroxyoxalate chemistry because it derives from the excited states formed by the decomposition of cyclic peroxides of oxalic acid derivatives called dioxetanes, dioxetanones, and dioxetanediones. 

A few years later it was discovered that certain substituted esters and amides of oxalic acid could also induce chemiluminescence from suitable fluoroph-ores in the presence of hydrogen peroxide. This class of chemiluminescent reactions has become known trivially as peroxyoxalate . 

---