Effects of high-voltage cathode rays on aqueous solutions of histidine monohydrochloride

Abstract

Aqueous solns. of histidine HCL containing 100, 250 and 1000 [mu]g./ml. were irradiated with high-voltage cathode rays at 4 levels, namely, 100,000,250,000, 500,000 and 1,000,000 rep. Histidine was decomposed at all concns., and the decomposition was related exponentially to the dosage of irradiation. The ionic yields ranged from 0.34 to 3.4 over the range of concns. studied. Data are presented to show that the action of high-voltage cathode rays on histidine is indirect. It is concluded that cathode rays decompose histidine through deamination of the alpha-amino group and the fission of the imidazole ring.