Gas chromatographic and electron spin resonance investigations of gamma-irradiated frog legs

Abstract

Several very sensitive techniques to measure radiation-induced products in frog legs were investigated. Presented here are results from the use of electron spin resonance (ESR) spectroscopy and capillary gas chromatography (GC) to measure radiolysis products in γ-irradiated frog legs. When bone is irradiated, a characteristic ESR signal develops and is easily measured. The intensity of the ESR signal is dose-dependent and stable for several months at room temperature. When triglycerides or fatty acids are irradiated, some of the major stable products formed are hydrocarbons with one less carbon than the precursor fatty acids. These hydrocarbons are formed as the result of the loss of CO 2 during various free radical reactions. A capillary GC procedure was developed to monitor the formation of these hydrocarbons in γ-irradiated frog legs. Since frog legs contain large amounts of palmitic, stearic, oleic, and linoleic acids, the formation of the hydrocarbons (pentadecane, heptadecane, 8-heptadecene, and 6,9-heptadecadiene, respectively) from the decarboxylation of these fatty acids was monitored. The yields of these hydrocarbons were found to be linear with applied dose. A sample from a lot of imported frog legs that were believed to have been treated with ionizing radiation was also analyzed. The ESR technique, in conjunction with the GC data on the hydrocarbons, appears to be a useful approach for identifying and monitoring frog legs that have been treated with ionizing radiation.