The proton-capture reactions ¹⁴N(p, γ)¹⁵O and ¹⁵N(p, αγ)¹²C have been studied to determine their applicabilities to the analysis of materials for ¹⁵N enrichment. It is true that precision of the measurement concerned in these techniques cannot compete with mass spectrometry, but their ease of application is of great advantage to the fast handling of very large batches of samples from stable nuclide tracer experiments.