Self-Decomposition of Compounds Labelled with Radioactive Isotopes

Review: Self‐radiolysis of compounds containing tritium and carbon‐14

“…Lyophilized D‐[U‐ 14 C]ribose (5.8 mCi/mmol) stored in‐vacuuo at ambient temperature decomposes 0.53% per month affording D‐ribonic acid, D‐erythrose, D‐erythronic acid, glycolic acid, oxalic acid, and two and three carbon aldehydic fragments 47,97 . D‐[U‐ 14 C]Mannose (20.0 mCi/mmol) stored in‐vacuuo at ambient temperature decomposes 0.64% per month affording D‐mannose, D‐arabinose, D‐lyxose, D‐erythrose, D‐erythronic acid, D‐arabonic acid, glycolic acid, oxalic acid, and two and three carbon aldehydic fragments and trace quantities of 2‐oxogluconic acid, mannonic acid lactones, and four‐carbon aldehydic fragments 47,48 . The stability of carbon‐14 labeled glycerol is dependent on the position of the radiolabeling with increased stability observed when the carbon‐14 labeling is on the secondary carbon (Table 4).…”

“…Self‐radiolysis is a significant challenge for radio‐chemists and has necessitated the development of several techniques to stabilize radiolabeled compounds including the addition of stabilizing agents, 32,38,39 dilution with unlabeled compound, and modification of storage conditions (storage in solution or adsorbed on paper) 40–46 . While there have been several review articles written on the subjects of 14 C and 3 H decomposition of organic compounds, 47–54 many of these articles are over 50 years old and, as such, do not include data on the decomposition of recently prepared carbon‐14 and tritium containing compounds. In this paper, a comprehensive of review of the self‐radiolysis of compounds incorporating 3 H and 14 C radiolabels is presented, and the stabilities of the radiolabeled compounds are discussed with respect of functional groups on the radiolabeled compound.…”

A timeline of stable isotopes and mass spectrometry in the life sciences

“…One may speculate that discovery of DNA as carrier of genetic information and target for mutations played a role in this development. Also, chemical processes induced by radioactive decay were better understood (Bayly & Weigel, ). Safety regulations for work with radioisotopes were tightened markedly at the beginning of 1970s.…”

Stability and storage of compounds labelled with radioisotopes

“…Unfortunately it is difficult to calculate or obtain a reasonable estimate for the value of 'f' except in the simplest of cases (9). Consequently it has been the usual practice to assume a value of unity for If" for calculation purposes ; however, for practical purposes this is far from the truth and the possible implications of this should not be forgotten.…”

“…For tritium compounds the value of 'f' can be taken as unity because of the low penetrating power of the weak beta radiation, but for compounds labelled with other radioisotopes and stored under favourable conditions, the value of 'f' may be considerably less than unity. Unfortunately it is difficult to calculate or obtain a reasonable estimate for the value of 'f' except in the simplest of cases (9). Consequently it has been the usual practice to assume a value of unity for If" for calculation purposes ; however, for practical purposes this is far from the truth and the possible implications of this should not be forgotten.…”