The CrLVV Auger emission has been used to investigate the local chemical environment of Cr(VI) in connection with the photoreduction produced by a non-monochromatic X-ray source. We compared Cr(VI) in oxides on anodized Al exposed to a chromate solution, with Cr(VI) in oxides on Al/Cr alloys polarized in a borate solution. The former were found to be much more sensitive to photoreduction than the latter. This is correlated with the intensity of the CrLVV Auger emission, attributed to a charge transfer transition in the final state of the photoemission process. © 1991.