Identification of ¹³N-NH₃ and analysis of its radiochemical purity using high performance liquid chromatography-ultraviolet-flow-count

Objective To establish a new, rapid, and effective method to identify ¹³N-NH₃ and analyze its radiochemical purity.

Methods The chromatographic method of high performance liquid chromatography-ultraviolet(HPLC-UV)-flow-count was performed using a C18 column with mobile phase of acetonitrile and 5 mmol/L sodium 1-octanesulfonate solution(V/V=1/3)at a flow rate of 0.5 ml/min and a wavelength of 210 nm. 15% ¹³N-NH₃ and 0.1 mg/ml NaNO₃ were detected separately, and their retention times were compared and identified.

Results The UV retention times of NH₃ and NaNO₃ were 2.3 and 1.4 min, respectively, and the retention times of ¹³N-NH₃ and ¹³N-NO_x^- were 5.8 and 3.1 min, respectively. The established separation method using HPLC-UV-flow-count showed good efficiency.

Conclusion HPLC-UV-flow-count is a simple, valid, and rapid method to identify ¹³N-NH₃ and analyze its radiochemical purity.