Comparison of the stable products formed by fast atom bombardment and γ‐irradiation of glycerol

The major end‐products formed by fast atom bombardment (FAB) and γ‐irradiation of glycerol have been identified using capillary gas chromatography/mass spectrometry. The product distributions differ dramatically. Products resulting from the recombination of either carbon‐centered or oxygen‐centered radicals are evident for both sources of irradiation. However, the major FAB‐generated products are formed by the recombination of carbon‐centered [G – H] · radicals with other carbon‐centered radicals while the major γ‐radiolysis products result from the recombination of oxygen‐centered [G–H] · radicals with lower‐weight carbon‐centered species. γ‐Radiolysis of an N 2 O‐saturated aqueous solution of glycerol, experimental conditions that strongly favor the formation of carbon‐centered [G – H] · radicals at the expense of the oxygen‐centered species, yielded some products that were identical to those produced by FAB of neat glycerol. Finally, the free radicals produced by γ‐radiolysis of glycerol were investigated by electron spin resonance spectroscopy and spin trapping with 5,5‐dimethyl‐1‐pyrrolne‐TV‐oxide. The presence of only the carbon‐centered free radical was established by this technique. The implications of these results are discussed.