Fig. 4From: Terminalia chebula: a novel natural product colorimetric sensor for Fe2+ and Fe3+ ionsThe detection limit (via 3σ/slope) of T. chebula extract with (a) Fe2+ and (b) Fe3+ (fitting up to x = 0.000101(M), y = 0.09785 for Fe3+) on the basis of UV–Vis titrations. σ means the average of the standard deviationsBack to article page