Finding optimal photosensitisers for the decontamination of foods by the photodynamic effect.

A new method for sanitation based on the photodynamic effect is introduced. Photosensitisers are compounds that generate cytotoxic oxygen species and free radicals after excitation with appropriate visible light. The cell killing efficacy is due to their chemical structure, to the actual environment and therefore also to their degree of aggregation.

Dehydroascorbic acid in urine as a possible indicator of surgical stress.

Background/aim: L-Ascorbic acid (AA) is the predominant circulating form of vitamin C found in human blood. It has been hypothesized that surgical stress increases the vitamin C metabolite dehydroascorbic acid (DHAA). Vitamin C is mainly excreted through the kidneys.

Photodynamic action of some sensitizers by photooxidation of luminol.

We report the development of a novel simple experimental method which allows the comparison of new photosensitizers based on their production of reactive oxygen species. A high-performance liquid chromatography (HPLC) assay permits the monitoring of several substances (sensitizer, reactant and oxidized end product) simultaneously on a single chromatogram. Photoreactions were monitored throughout their course by the HPLC assay surveying the sensitizers' efficiency of singlet oxygen production by the oxidative decomposition of luminol.