Micro-X-ray Fluorescence Analysis of Sr in Fish Otolith of Ayu Plecoglossus altivelis

Abstract

We have applied a polycapillary X-ray focusing optic to a micro X-ray fluorescence analysis (micro-XRF) instrument. The spatial resolution of the developed instrument was about 10 micrometers. We used the micro-XRF instrument to determine the migratory environmental history of a fish (ayu : Plecoglossus altivelis) from the Sr intensity profile in a otolith (ear stone). The obtained 2D elemental map showed a high concentration of Sr distributed in the center of the otolith, indicating that this ayu stayed in the sea during the corresponding period. In order to investigate the migratory environmental history of the ayu, we compared captured fishes with cultivated fishes based on the Sr intensity profile. The results suggest that captured fishes include four cultivated fishes. We could easily estimate the migratory environmental history of fishes by using this method and measured nondestructively in air. © 2012, The Japan Society for Analytical Chemistry. All rights reserved.