Sensing Chemicals In People, Food
Until now, sensors for salicylates—the active pain-killing ingredient in aspirin—and sulfites, which are commonly found in preserved foods, certain beverages, and even acid rain, have not been available. But using established electrochemical membrane-sensing technology, University of Michigan chemist Mark Meyerhoff has developed two polymeric-membrane electrodes that he says have potential for monitoring aspirin toxicity in patients taking large amounts of the drug for pain; for monitoring sulfite levels in the food and beverage industries; and for atmospheric environmental monitoring. The salicylate-selective electrode uses a plastic membrane saturated with Tin (IV)-Tetraphenylporphyrin. When a saturated membrane comes in contact with human blood or urine containing salicylate ions, a chemical reaction binds the ions to specific locations on the porphyrin molecule in the membrane phase. This reaction creates an electrochemical potential proportional to the amount of salicylate present in solution. Using the same principles, Meyerhoff dopes a polymeric...