The cross-section of the N14(α,p0)O17 reaction at angles of 90°, 135°, and 165° was measured for incident energies between 3.5 and 6.0 MeV simultaneously with the cross-section of the N14(α,α)N14 reaction at 165°. Interference between these two reactions at the angle of 165° and around 3.9 MeV was taken into account. The technique used is very powerful, thanks to the Ta450 nm/C target being implanted with a high dose of nitrogen. The N14(α,p0)O17 reaction exhibits some resonances allowing traces of nitrogen to be quantified. This reaction also offers an alternative to the N14(d,α)C12 and N14(H3e,p)O16 nuclear reactions for profiling nitrogen in the first few microns below the surface. Moreover, by using α-particles, Rutherford backscattering spectroscopy can be performed simultaneously with a good mass resolution to depth profile high Z elements in the sample. The sensitivity of these reactions (0.1%) has been tested by measuring the nitrogen traces in a titanium oxide film deposited on silicon. Depth profiling of nitrogen in a TiN layer on a silicon substrate was also performed. In addition, we publish for the first time some cross-sections values for the N14(α,p1)O17 reaction at 90° and 165°; this measurement is a challenging task.