Production of ¹³N‐labelled molecular nitrogen for pulmonary function studies

Optimizing [13N]N2 radiochemistry for nitrogen‐fixation in root nodules of legumes

“…The nitrogen-13 was recovered in the hot lab ( Figure 5) 13 N]NH 3 trapping, vessel B was vented to a Sicapent TM trap (P 2 O 5 , Aldrich Chemical) and NaOBr solution was remotely introduced into vessel C, which was prepared according to the procedure by Vaalburg et al 17 During oxidation, the evolving […”

“…Quite remarkably, there has been only one paper published that addresses these issues. 17 This work relied on a two-step process involving the reduction of [ 13 3 decay corrected to EOB), and the absolute specific activity averaged 2.5EÀ01 MBq mmol À1 . Typically, we were able to prepare $259 MBq of gaseous […”

Nitrogen‐13: historical review and future perspectives

“…Because of the short half-life of 13 N (9.97 min), the distribution of 13 N-labeled radiotracers from large production facilities to surrounding clinical centers or research laboratories is unrealistic or, at least, very challenging. In addition, the high positron range (maximum energy of 1.19 MeV, maximum range in water of 5.4 mm) usually leads to low resolution images, especially when compared with those obtained with 18 F-labeled radiotracers (maximum energy of 0.69 MeV, maximum range in water of 2.4 mm). As a result, the use of 13 N has been historically very restricted, and only a few studies describing new synthetic strategies for the incorporation of this radioisotope into bioactive molecules have been reported to date.…”

“…However, 13 N can be produced in different chemical forms in the cyclotron; thus, the potential applications and synthetic opportunities offered by this interesting isotope go far beyond the production and use of [ 13 N]NH 3 . In addition, the stable isotope of nitrogen ( 14 N) is present in the majority of biological active molecules; therefore, the incorporation of 13 N in the toolbox of positron emission tomography (PET) chemists might be a valuable option for the preparation of new labeled compounds or incorporation of the label in different positions, providing further information related to the in vivo behavior of radiotracers and becoming an interesting alternative to 11 C and 18 …”

“…Nitrogen-13 ( 13 N), together with 18 F, 15 O and 11 C, is one of the positron emitters that can be produced on the multigigabecquerel scale in biomedical cyclotrons. Currently, it is usually generated via the 16 O(p,α) 13 N nuclear reaction by irradiation of 5 mM ethanol aqueous solution with high-energy protons.…”