Use of a Nafion Membrane Probe for Quick, On-the-Spot Determination of Ionic Copper Contamination Levels in Natural Waters

摘要

A major source of trace metal contamination in the marine environment comes from the copper containing anti-fouling paints on ship hulls. This study tests the hypothesis that the organic molecule, 2,9-dimethyl-4,7- diphenyl-1, 10- phenanthroline (Bathocuproine=BCP) attached to the polymer Nation 117 is a reliable chemical for developing a sensor capable of measuring Cu(l) in seawater. The purpose is to develop a sensor system that will measure Cu (I) contamination quickly. The sensor must have parts per billion (ppb) detection limits, marine environmental immersion capability, and the ability to detect the copper oxidation state. An easily and readily deployed sensor can yield results that will allow the deployment of remedial methods to avert an environmental problem. The developed sensor uses the perfluorinated ionomeric film, Nation 117. This film has a Teflon matrix with sulfate side groups that facilitates the BCP/copper reaction. When the Nation 117 membrane with the imbedded BCP is exposed to Cu(l), it will turn a shade of orange corresponding to the Cu(l) concentration. The developed Cu(l) concentration on the membrane is readable with a comparator, with a fiber optic sensor or with a colorimeter. In the marine environment, anti-fouling paint containing Cu(l) presents a challenge because it is designed to leach continuously over a period of time. The Cu(l) is a biocide that kills or prevents attachment of organisms to a ship hull, but, also is a pollutional source. The conclusions from this study are: that the chemical procedure using the BCP impregnated Nation 117 membranes affords a probe to test for total available ionic copper (I) and (II), that the chemical procedures used are reproducible and robust, that the environment plays a role in the reaction of the probe with available ionic Cu (I) and (II), that the Nation 117 membrane impregnated with BCP detects Cu(l), and that there is a knowledge base for continuing and expanding the studies.