Application of gamma irradiation on breakdown of hazardous volatile N-nitrosamines

Gamma irradiation was applied for the breakdown of the volatile N-nitrosamines (VNAs), nitrosodimethylamine (NDMA), and nitrosopyrrolidine (NPYR). NDMA and NPYR were dissolved in distilled water, dichloromethane, or ethanol, and irradiated at 2.5, 5.0, 7.5, 10, 15, 20, and 25 kGy by gamma ray. Samples were analyzed by GC-TEA. NDMA and NPYR in distilled water and dichloromethane were easily broken at 5 kGy or above. NPYR was the most sensitive to irradiation, while the NDMA is relatively resistant to irradiation. NDMA and NPYR dissolved in ethanol was the most resistant to irradiation and the breakdown was 90% or above at 20 kGy, VNA formation was not observed by in vitro test from decomposed compounds without nitrite, while the VNAs were found by exposure of irradiated products to nitrite. Results indicated that the gamma irradiation technology may be effective to reduce carcinogenic VNA contents in food and other industry.