||JRB Associates, Inc., McLean, VA. ;B and M Technological Services, Inc., Cambridge, MA.;Environmental Protection Agency, Edison, NJ. Hazardous Waste Engineering Research Lab.
An enzyme-based approach for detecting hazardous levels of high molecular weight chlorinated hydrocarbons in natural waters has been explored. An extensive review of the literature indicated that the enzymes, lactate dehydrogenase, carbonic anhydrase, hexokinase, phosphorylase and an ATPase are suitable for field method development. Lactate dehydrogenase (LDH) was chosen to develop a method that promises rapid, reliable and cost-effective detection. The LDH catalyzed reaction is used to detect chlorinated hydrocarbons, which reduce the rate of the reaction by reversibly inhibiting the enzyme. The analysis uses pH detection and takes 5 minutes. So far, the LDH method has been used to detect aldrin, toxaphene, DDT, PCBs, pentachlorophenol and 2,4,5,-T at the parts per million level. A review of the literature suggests that most organochlorine pesticides, PCBs, polychlorinated phenols and chlorophenoxy derivatives can be detected by the LDH method. Preliminary investigations of potential interferants suggest that the LDH method selectively detects chlorinated hydrocarbons. Work was begun on immobilizing the enzyme for incorporation in water monitor and field detector designs. The LDH method shows potential for use in field devices and for processing extracts of soils and wastes, as well as water samples. These method adaptations are recommended for future work.