Patent Number: 
Section: claims

1. An elution capsule, comprising:a tube with a first end portion having a first inside diameter, a second end portion having a second inside diameter;a singular first opening in the first end portion and a singular second opening in the second end portion, the first and second openings facing opposite directions and being about collinear with a longitudinal centerline of the tube;a middle portion between the first end portion and the second end portion and having an inside diameter smaller than the inside diameters of the first and second end portions, wherein an interface between the first end portion and the middle portion forms a first shoulder and an interface between the second end portion and the middle portion forms a second shoulder;a first washer inside the first end portion contacting the first shoulder;a first filter inside the first end portion contacting the first washer;a second filter inside the first end portion contacting the first filter, the first filter being located between the first washer and the second filter;a first end cap sealing the first opening;a second washer inside the second end portion contacting the second shoulder;a third filter inside the second end portion contacting the second washer;a fourth filter inside the second end portion contacting the third filter, the third filter being located between the second washer and the fourth filter; anda second end cap sealing the second opening. 2. The elution capsule of claim 1, wherein the cross-sections of the first end portion, the second end portion, and the middle portion are annular. 3. The elution capsule of claim 1, wherein the first inside diameter and the second inside diameter are the same. 4. The elution capsule of claim 1, wherein a length of the first end portion and a length of the second end portion are the same. 5. The elution capsule of claim 1, wherein first and third filters are glass wool and the second and fourth filters are one of glass frits and porous discs, the second and fourth filters being formed from one of borosilicate glass, quartz glass, polyethylene, and resin. 6. The elution capsule of claim 5, wherein the glass wool includes at least one of borosilicate glass wool, quartz glass wool, and glass fiber. 7. The elution capsule of claim 1, wherein the first end cap comprises:a hollow body, wherein an outside surface of the hollow body is tapered to allow for press fitting the first end cap into the first opening to create a seal at the first opening; anda cover configured for puncturing by needles and configured to bear against an outside surface of the first end portion. 8. The elution capsule of claim 7, wherein the hollow body of the first end cap has an annular cross section and an outside diameter of the cross section varies along an axis of the hollow body and the cover has a solid circular cross section with an outer diameter greater than the inner diameter of the first end portion. 9. The elution capsule of claim 1, wherein the first washer has an annular cross section with an outside diameter less than the first inside diameter of the first end portion and the second washer has an annular cross section with an outside diameter less than the second inside diameter of the second end portion. 10. The elution capsule of claim 1, wherein the tube is made from at least one of high purity zirconium, aluminum, glass and quartz. 11. The elution capsule of claim 1, further comprising:a first epoxy layer between the first end cap and the first end portion and a second epoxy layer between the second end cap and the second end portion. 12. The elution capsule of claim 1, further comprising:a first flexible seal on an outside of the first opening and a second flexible seal on an outside of the second opening. 13. The elution capsule of claim 12, further comprising:a first adhesive layer between the first flexible seal and the first end portion and a second adhesive layer between the second flexible seal and the second end portion. 14. A system, comprising:the elution capsule of claim 1,wherein material is included in the middle portion of the elution capsule, the material including one of titanium molybdate, zirconium molybdate, titanium tungstenate, and zirconyl tungstenate. 15. The system of claim 14, further comprising:a nuclear reactor having a neutron flux, wherein the elution capsule is in the neutron flux of the nuclear reactor. 16. The system of claim 14, wherein,the first end portion of the elution capsule is configured to be punctured by an elution needle to supply elution solution into the elution capsule in order to contact the material,the second end portion of the elution capsule is configured to be punctured by a vacuum needle to provide a vacuum to draw the elution solution through the material to collect an eluant. 17. The system of claim 16, wherein the elution solution is one of distilled water, deionized water, saline, oxidizers, acids or bases.