Ionisation profile of gas within the host galaxy of six GRBs as traced by nitrogen. Ionisation state of the gas is divided into three broad components; neutral (N_ntr), highly ionised (N_V), and ultra-ionised (N_ultrion). Highly ionised nitrogen, N v, is measured directly from optical spectra, whereas the column density of neutral nitrogen is determined from either S ii (black circles) or Zn ii (grey circles), and the ultra-ionised column density of nitrogen gas is determined from X-ray measurements. The downward pointing triangle represents an upper-limit.