Fig. 4

False colour RGB composite image generated following SR µXRF maps of Cd/Zn/S and S^−II/S^VI [step size (h × v), 1 × 1 µm²; exp. time, 10 ms/pixel] and average XANES spectra recorded at the S K-edge of selected ROIs belonging to sample A4 and A7. It is noted that the detection limit for Zn L-lines in the current experimental conditions is very low