Environmental photodegradation of mefenamic acid.

Abstract

Pharmaceuticals and personal care products are an emerging class of environmental pollutants. Photolysis is expected to be a major loss process for many of these compounds in surface waters, including the common non-steroidal anti-inflammatory drug mefenamic acid. The direct photolysis solar quantum yield of mefenamic acid was observed to be 1.5+/-0.3x10(-4). Significant photosensitization was observed in solutions of Suwanee River fulvic acid and Mississippi River water, as well as for the model photosensitization compounds 3'-methoxyacetophenone, 2-acetonaphthone and perinaphthenone. Quenching, sparging and light-filtering experiments suggested a direct reaction of mefenamic acid with excited triplet-state dissolved organic matter as the major photosensitization process. The persistence of the model photosensitizer suggests that the photosensitization by perinaphthenone occurs either by triplet-energy transfer or an electron transfer followed by rapid regeneration of the sensitizer. Due to its low quantum yield, the loss of mefenamic acid in sunlit natural waters is expected to depend on both direct and indirect photodegradation processes.

• Authors: Jeffrey J Werner, Kristopher McNeill, William A Arnold
• Journal: Chemosphere (Chemosphere) Vol. 58 Issue 10 Pg. 1339-46 (Mar 2005) ISSN: 0045-6535 [Print] England
• PMID: 15686751 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Benzopyrans
• Photosensitizing Agents
• Water Pollutants, Chemical
• Mefenamic Acid
• fulvic acid

Topics

• Benzopyrans (chemistry)
• Chromatography, High Pressure Liquid
• Kinetics
• Mefenamic Acid (chemistry)
• Photochemistry
• Photolysis
• Photosensitizing Agents (chemistry)
• Rivers
• Sunlight
• Water Pollutants, Chemical (analysis)