This grant in the Analytical and Surface Chemistry Program provides support for Professor Weber's investigations of the fundamental issues and problems associated with the development of useful membrane sensors for organic anions and the development of microextraction devices for these anions. Potentiometric sensors for cations have been successfully implemented for a variety of species, and the results have had a dramatic impact in the fields of bioanalytical chemistry and biotechnology. Professor Weber proposes to create new sensors for anionic species by synthesizing new artificial receptors for the selective extraction of anions into plasticized polymer media. New anion sensors for ions such as carboxylates, glutamate and aspartate are urgently needed in such diverse areas as neurochemistry, the food industry and biotechnology. This grant in the Analytical and Surface Chemistry Program will support research into the development of practical membrane sensors for organic anions. The goal is to create a suite of anion sensors similar in function to those already existing for cationic species. The research will involve the synthesis and characterization of artificial receptors which will selectively extract anions into polymeric membranes. The sensors will be used to detect anions such as acidic neurotransmitters, decomposition products in food, and waste products in bioreactors