Patent Number: 039705838
Section: description

The reference numeral 1 in this Figure refers to a reservoir which is provided with an inlet opening 2 at the top and an outlet opening 3 at the bottom. The reservoir is substantially cylindrical and is provided with a flange position 4 at either end. In the lower part of the reservoir has an internal diameter transition 5. At the location of the diameter transition 5 the reservoir 1 is provided with a trapezoidal glass filter 6. The openings 2 and 3 of the reservoir are closed by a rubber stopper 7 which comprises a flange portion 8 and a jacket portion 9. The jacket portion 9 fits the openings of the reservoir 1, whilst the flange portion 8 engages the flange portion 4 of the reservoir 1. The flange portion 8 of the stopper 7 and the flange portion 4 of the reservoir 1 are connected to each other by means of a metal capsule such as an aluminium capsule 10. The capsule 10 has an opening 11. The reservoir 1 contains a carrier material for a parent isotope. Said carrier material consists of an upper layer 12 and a lower layer 13. The upper layer 12 contains Al.sub.2 O.sub.3 particles which are entirely or partially coated with a layer of hydrated or partially hydrated manganese dioxide. The lower layer 13 consists of Al.sub.2 O.sub.3 particles. The total weight of the carrier material is for example 7 grammes, of which 3 grammes are contained in the upper layer. In the reservoir the carrier material is enclosed between the glass filter 6 and a micropore filter 14 which is pressed against the carrier material by means of a washer 15. The upper layer 12 contains the radioactive parent isotope 99m Mo in the form of an alkali metal molybdate such as sodium molybdate. When using the isotope generator according to the invention shown in the Figure a washing liquid such as a physiological salt solution is admitted at the top via a hollow injection needle inserted through the upper rubber stopper 7. The washing liquid passes through the micropore filter 14 and subsequently through the upper layer 12 of the carrier material. In said upper layer the parent isotope 99m Mo in the form of sodium molybdate on the carrier material is absorbed. Owing to radioactive decay of 99m Mo the upper layer will also contain 99m Tc in the form of sodium pertechnate. The washing liquid absorbs the pertechnate containing the 99m Tc and subsequently passes through the lower layer 13 of the carrier material. After having passed the filter 6 the washing liquid with 99m Tc is collected in a receptacle via an injection needle inserted through the lower rubber stopper 7. The radioactive eluate thus obtained is of a high chemical purity, i.e. it contains no contaminations such as Al.sup.+.sup.+.sup.+ ions, it has a pH value of 6.5 - 7.5 and is directly suited for use in medical diagnosis.