Figure 5. IP read-out images to show the desorption of ¹³⁷Cs by HCl solution (pH 1) from WB particles, which sorbed ¹³⁷ Cs from the solution (18.5 Bq) with different reaction periods, and that from “natural” radioactive WB particles collected in Fukushima.

Notice that the images before the elution are the same as those at the top of Fig. 3, except for the “natural” particles. Total radioactivity before the elution is shown at the top, and the percentage of ¹³⁷Cs remaining in the mineral particles after the elution is shown at the bottom.