Radioactive material generator

Abstract

A radioactive material generator includes radioactive material in a column, which column is connected to inlet and outlet conduits, the generator being embedded in a lead casing. The inlet and outlet conduits extend through the casing and are topped by pierceable closure caps. A fitting, containing means to connect an eluent supply and an eluate container, is adapted to pierce the closure caps. The lead casing and the fitting are compatibly contoured such that they will fit only if properly aligned with respect to each other.

Parent Case Text

This is a continuation-in-part application of Ser. No. 357,433, filed May 4, 1973, now abandoned.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a radioactive material generator, and in particular, the combination of such a generator and a fitting which permits eluent supply means and eluate withdrawal means to be operatively coupled thereto.

The use of radiosotopes in medicine, for diagnosis and treatment, is well known and its use is under great expansion. Generally, isotope solution is eluted from a radioactive material generator when and as the material is to be utilized. THe reason for this is that the daughter isotope generally has an extremely short half-life and must be prepared at the proximate time of use. To satisfy this requirement, numerous systems have been devised to enable the physician to assemble the various components of the generator and then elute the usable solution.

The radioactive generators have traditionally been of the type shown in U.S. Pat. No. 3,369,121 issued Feb. 13, 1968 and U.S. Pat. NO. 3,440,423 issued Apr. 22, 1969. As there described, the generator comprises radioactive material such as a column of alumina impregnated with Mo.sup.99. The daughter isotope, in this case Tc.sup.99m, is eluted from the generator by means of a saline or dilute hydrochloric acid solution. The alumina is suspended in a plastic housing and naturally there must be means supplied to introduce the eluent and to withdraw the eluate, i.e., the isotope solution. In the prior art, these means have comprised pierceable stoppers through which the fluids are introduced and removed by means of hypodermic needles. Recent developments include the provision of inlet and outlet conduits which are similarly sealed by pierceable stoppers.

In all of the prior art embodiments, cumbersome and complex protective equipment had to be utilized to protect various personnel from being exposed to the emission of the generator. The various protective equipment utilized required the physician to assemble heavy parts and suspend various bottles, in short, calling upon him to perform far too many manipulations. The present invention is directed to a fitting which renders the generator quite simple to use, eliminates unnecessary manipulations, and at the same time provides complete protection against radioactive emissions.

SUMMARY OF THE INVENTION

The generator incorporated in the instant invention comprises a column of alumina inpregnated with Mo.sup.99. The alumina is suspended in a cylindrical housing annd the housing is sealed at both ends. An inlet conduit, for the introduction of the eluting solution, is provided and connected to the upper portion of the housing. An outlet conduit, for withdrawing eluate from the generator, is provided and connected to the lower end of the housing. Both conduits are sealed by means of pierceable caps.

The housing and conduits are embedded in a wing-shaped, split lead casing, the casing interface being contoured to conform to the housing contour and the contours of the conduits. Each section of the split casing is suitably contoured to accept a portion of the housing and of each conduit. Additionally, the interface is composed of alternate ribs and grooves, and may include other means, such that there is only one position at which the casing sections can be joined. The casing sections are suitably joined, as for example, by means of nuts and bolts, snap clasps, or other suitable means.

The conduit sealing caps may protrude above the top surface of the casing, above raised platforms which are situate at the top left and top right corners of the casing, or these conduit sealing caps or covers may be housed within the lead casing to provide additional radiation shielding. The interior sidewalls of the platforms are formed into parallel arcuate sections or other nonsymmetrical surfaces. This formation constitutes a key-way which insures proper alignment of the fitting when it is assembled to the casing.

The fitting incorporated into the instant invention comprises a lead bar having adjacent the respective ends thereof, holes into which inserts are received, which inserts accommodate eluent supply means and eluate withdrawal means. Those holes are positioned such that they are directly above the sealing caps of the inlet and outlet conduits upon assemblage of the fitting to the casing. The eluent supply and eluate withdrawal means are adapted to accommodate the eluent container and the eluate container, preferably an evacuated vial which draws the desired solution out of the generator.

To insure proper assemblage of the fitting and the casing, the fitting is provided on the undersurface thereof with a plug or boss having lateral surfaces complementary to the surfaces of the interior sidewalls of the raised platforms on the top of the casing. When such interior sidewalls are parallel arcuate sections, the boss may be of generally circular shape (the diameter being identical to that of the arc of each interior sidewall of the platforms) so that the boss mates with one of the sidewalls, and a guide section, which is adjacent to and of the same arcuate contour as the other platform sidewall, mates with the other sidewall. The provision of what is effectively a key and key-way structure eliminates the possibility that the fitting will be improperly assembled to the casing.

The eluent supply means and eluate withdrawal means are preferably incorporated into a unitary molded plastic receptacle holder for the eluent container and the eluate container. This receptacle holder also provides the means, including the two double ended hypodermic needles, for fluid connection between the eluent container and the inlet conduit and between the eluate container and outlet conduit through the pierceable closure caps of the containers and the conduits. The receptacle holder may be connected to the lead bar of the fitting to form an integrated unit or the receptacle holder may be provided with a locating or positioning pin and releasable fasteners so that it may be mounted on the lead bar in the proper operative position at the time of use.

The above and other aspects of the present invention will be further amplified as the description continues, and when read in conjunction with the appended drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fitting showing all the structure on the bottom thereof;

FIG. 2 is a perspective view of a casing showing the structure on the top thereof;

FIG. 3 is a front elevational view of a fitting, cross-sectioned to show the needle structure thereof;

FIG. 4 is a perspective view of a generator partially cut-away to reveal the connection therewith of the outlet conduit;

FIG. 5 is a front elevational view of the casing of FIG. 2 showing the interior of the split sections of the casing in side by side relation;

FIG. 6 is a front elevational view of the fitting of FIGS. 1 and 3 assembled to the casing of FIGS. 2 and 5, partially cut-away to expose the needles piercing the sealing caps;

FIG. 7 is a perspective view of an alternative embodiment of a portion of a fitting showing a receptacle holder with needle adapter assembly and the structure on the bottom thereof;

FIG. 8 is a perspective view of an alternative embodiment of a casing showing the structure on the top thereof;

FIG. 9 is a front elevational view of an alternative embodiment of a fitting, exploded and partly in cross-section to show the receptacle holder with needle adapter assembly of FIG. 7 and the manner of joining the receptacle holder and the lead bar portions of the fitting; and

FIG. 10 is a front elevational view of the casing of FIG. 8 showing the interior of the split sections of the casing in side by side relation.

DETAILED DESCRIPTION

The present invention incorporates a radioactive material generator 10 as illustrated in FIG. 4. That generator is similar in operative aspects as that shown and described in U.S. Pat. No. 3,369,121 and 3,440,423. The generator 10 comprises the cylindrical housing 12 in which a chromatographic grade of alumina, impregnated with Mo.sup.99, is suspended. The generator 10 is milked of its product solution, containing Tc.sup.99m, by means of an eluent which may be saline, dilute hydrochloric acid or other suitable solutions. The system for eluate withdrawal from the generator and for introducing the eluent will be described in greater detail as the description continues.

The generator 10 is sealed at its top 14 and bottom 16 by stoppers 17 which are adapted to be pierced by hypodermic needles for the purpose of loading the generator 10. The radioactive molybdenum solution can thereby be introduced by pypodermic needle and connected syringe or other suitable means through the top stopper 17 into contact with the alumina and the excess solution drawn off by piercing the bottom stopper 17 with a hypodermic needle connected to a syringe or to a vacuum line. The stoppers 17 are preferably formed of a gas pervious, pierceable material which is autoclavable, such as silicone, e.g., methylvinylpolysiloxane. As noted in U.S. Pat. No. 3,801,818 issued Apr. 2, 1974, such closures or stoppers are capable of venting gases which may be internally generated during the autoclaving procedure by which the generator 10 is sterilized.

In most prior art generators in which the top and bottom are closed by pierceable seals, the eluent is added and the eluate is withdrawn through such seals. The generator 10 of the instant invention provides for eluent addition via a conduit 18 and eluate removal via conduit 20. In this embodiment the conduits are shown as being separate tubes encapsulated within projections 22, 24 which are unitary with the housing 12. It should be evident that the conduits 18, 20 may be unitary with the housing 12, the entire unit being formed of a molded plastic. It is to be noted that the outer terminal ends of the conduits 18, 20 are sealed by means of covers or caps 26, 28. The covers 26, 28, according to FIG. 4, comprise a molded cup 30 having a stem 32, which stem encapsulates the upper terminus of the conduits 18, 20. The open ends of the conduits 18, 20 however, are not blocked by cup 30, but are open to the cup chamber. A pierceable closure 34, fabricated from material such as silicone or neoprene, is sealingly received in the cup 30, and is held in place by means of a flexible metallic ring 33 which is crimped about the cup 30 and the closure 34.

From the structure thus far described, it follows that eluent is injected into the generator 10 by being passed through the closure 34 into the cup 30, and from there into inlet conduit 18. By providing a reduced pressure in cover 28, the eluent is sucked through the generator 10, passing through the alumina bed where it picks up the Tc.sup.99m, into the lower chamber 38, and into the lower terminus 40 of the outlet conduit 20. An evacuated container is advantageously used to provide the reduced pressure in cover 28, and it draws the fluid out of cup 30 in cover 28. This eluate is immediately ready to be injected into a patient.

The generator hereinbefore described must be properly shielded inasmuch as the physician and the patient should not be unnecessarily exposed to the emissions therefrom. Accordingly, a lead casing is provided to house the entire generator 10. As shown in FIGS. 2 and 5, the casing 42 is vertically split into two parts 44, 46. The mating interior surfaces which form the interface of joinder are suitably contoured to closely accommodate therein the generator 10 and the conduits 18, 20. To this end, each is provided with a central depression 48 which accepts the cylindrical housing in close confinement. Channels 50, 52 are provided for the acceptance of the conduits 18, 20. The part 44 may be made thicker than part 46 and will therefore more deeply accommodate the generator 10 and conduits 18, 20. In this fashion the channels will be formed in the part 44, there being only slight depressions 54, 56 in the part 46 to complement the channels 50, 52. Depressions 58 are provided in various positions to accommodate the projections 22, 24 and stems 32. The interior surfaces of the parts 44, 46 are ribbed and grooved to insure that those parts are properly mated.

As shown in FIG. 2, when the parts 44, 46 are joined the casing 42 resembles a fuselage-like section 60 flanked by wings 62, 64. The parts 44, 46 may be joined by means of screws (not shown) received in openings 68, and nuts (not shown) received in countersunk holes in one of the parts to provide a secure joinder. It is obvious that other means of joining parts 44 and 46 may be used. The wings 62, 64 are seen to terminate in upper flat surfaces 70, 72, which surfaces integrate into the fuselage 60. The surfaces 70, 72 respectively step up to platforms 74, 76 which are also flat. It is important to note the configuration of the respective sidewalls 78, 80 of those steps. Each sidewall is arcuate and they are essentially parallel. This configuration provides a key-way the function of which has been described previously and will be more evident as the description continues. It is to be recognized, that when the generator 10 is enclosed in casing 42, the covers 26, 28 are situate above the platforms 74, 76 to make them accessible to the eluent supply and eluate withdrawal equipment illustrated in FIGS. 1 and 3.

Turning now to FIGS. 1, 3 and 6 the eluent supply and eluate withdrawal equipment is integrated into a fitting 100. That fitting's major component is a rectangular lead bar 102 which includes the holes 104, 106 adjacent the respective ends thereof. Protruding from the undersurface of the bar 102 is a boss or disc-like member 108 which can be of unitary construction with that bar. The disc 108 is of sufficient diameter to generally cover the entire area between the platforms 74, 76. That disc includes a guide surface 110 which is of the same contour as the sidewall 78. It should be evident that the guide surface 110 will mate only with sidewall 78 and not with sidewall 80. This insures that when the fitting 100 is assembled to casing 42 they will be properly aligned.

As shown in FIGS. 1, 3 and 6, a unitary molded plastic receptacle holder 112 is connected to the upper surface of bar 102 by way of the skirts 114, 116 which depend into recesses 118, 120 in the bar sidewalls 122, 124 and are crimped about ribs 126, 128 respectively. The receptacle holder 112 includes a holder 130 for an eluate container, preferably an evacuated vial. That holder extends into hole 106 and above the top surface of receptacle holder 112. The holder 130 is sealed at the top and bottom of the bar 102 except for the central portion which supports a double ended hypodermic needle 132. It is through that needle that the eluate is withdrawn via outlet conduit 20. The receptacle holder 112 also includes an eluent container holder 134 which, like holder 130 extends into the bar 102 and projects thereabove. The holder 134 is also similarly sealed and supports the hypodermic needles 136, 138. Needle 138 is similar to needle 132, it is double ended and serves to conduct eluent into the generator 10. The needle 136 does not extend below the upper surface of bar 102 and serves only to provide an inlet for air into an eluent container. The conduit 142 connects needle 136 with the atmosphere through a hydrophobic filter (not shown). A filter (not shown) may be incorporated at the lower portion of the holder 130 to remove any particulate matter that may pass into the needle 132.

In use, the physician assembles the components of the system illustrated in FIGS. 1 through 6 at the proximate time of usage. Initially, the generator 10, enclosed in the casing 42, may be stored in a lead pig for further protection against emission. The fitting 100 is then assembled to the casing 42 by properly aligning the disc 108 and pressing on the fitting until the needles 132, 138 pierce the respective closures 26, 28 of the inlet and outlet conduits 18, 20. An eluent container (not shown) is assembled upside down on the holder 134, the neck thereof being received therein; and the needles 136, 138 pierce a sealing diaphragm of that container. A completed entry path from the eluent container through needle 138 and inlet conduit 18 is now defined into the interior of generator 10. An evacuated vial is then similarly assembled atop the holder 130 as the eluate container, with the needle 132 piercing its sealing diaphragm. The pressure differential produced by the evacuated eluate container draws the eluent through the needle 138, through the closure 34, through conduit 18 and through the alumina where it picks up the Tc.sup.99m. Thereafter the eluate is drawn into bottom chamber 38 from which it passes into conduit 20. It is then drawn through needle 132 and into the eluate container.

An alternative embodiment of the casing and of the fitting are illustrated in FIGS. 7 through 10.

As shown in FIGS. 8 and 10, the lead casing 242 is very similar to the embodiment illustrated in FIGS. 2 and 5. The casing 242 is in two vertical sections 244, 246. The mating interior surfaces of the sections 244 and 246 which form the interface of joinder are suitably contoured to closely accommodate therein the generator 10, the inlet and outlet conduits 18, 20, and the covers or caps 26, 28. For this purpose, each of the sections 244, 246 is provided with a central depression 248 which accommodates the cylindrical housing 12 of the generator 10 in close confinement. The depression 248 extends from the top to the bottom of each of the sections 244, 246 to provide in the assembled casing 242 an access opening to each of the pierceable stoppers 17 at the top 14 and the bottom 16 of the housing 12 of the generator 10 contained within the casing 242. These openings are provided to permit loading of the generator 10 after it has been enclosed within the lead casing 242. Channels 250, 252 are provided for the inlet and outlet conduits 18, 20. The sections 244, 246 are substantially the same thickness, and therefore, each provides substantial portions of these channels 250, 252 for the conduits 18, 20. The interior ends 258 of the channels 250, 252 accommodate the connections (shown in FIG. 4 as projections 22, 24) of the conduits 18, 20 to the cylindrical housing 12 of the generator 10. As shown in FIG. 10, channels 250, 252 provide for a housing 12 and conduits 18, 20 which are molded as a single unit so that no projections (such as 22, 24 of FIG. 4) are present at the connections of conduits 18, 20 to housing 12. Depressions 259 are provided to accommodate the covers or caps 26, 28 which seal the outer terminal ends of the conduits 18, 20. In this embodiment of FIGS. 8 and 10, the covers 26, 28 are within the lead casing 242 to provide additional radiation shielding. The depressions 259 extend to the top surfaces of the platforms 274 and 276 of the casing 242 so that when sections 244, 246 are joined an opening is provided permitting access to the pierceable closures 34 of the covers 26, 28 of inlet and outlet conduits 18, 20. The interior surfaces of the sections 244, 246 are ribbed and grooved to insure that the sections 244, 246 are properly mated. In addition, four locating lugs 261 fit into four depressions 263 to hold the sections 244, 246 in proper position with respect to each other.

In FIG. 8, the sections 244, 246 are shown joined to form the casing 242 which is very similar to the casing 42 of FIG. 2, i.e., the casing 242 also resembles a fuselage-like portion 260 flanked by wing-like portions 262, 264. The sections 244, 246 may be fastened together by any suitable means providing a secure joinder. As shown in FIG. 8, the sections 244, 246 are held together by spring clips 265, which may be formed of any suitable material such as metal or plastic, in the notches 267 provided in the outside surface of each of the wing-like portions 262, 264 of sections 244, 246. The top of the casing 242 is formed of three flat surfaces 270, 274 and 276. The surface 270 surrounds the opening, formed by depression 248 in each of sections 244 and 246, at the top of the fuselage-like portion 260 and also extends over part of the top of each of the wing-like portions 262, 264 to the base of sidewalls 278 and 280 of the raised platforms 274 and 276 the top surfaces of which are flat and coplanar. The surfaces 274 and 276 each surround an opening formed by the depressions 259 in the sections 244 and 246. The sidewall 278 is formed by three angled vertical surfaces approximating an arc, and the sidewall 280 is a single vertical surface lateral to the sections 244, 246. Together these sidewalls 278, 280 form a keyway to cooperate with a key 208 of the fitting 200 to position the fitting 200 correctly on the casing 242 as will be described more fully later in the description. The platforms 274 and 276 are of sufficient height to enclose the covers 26, 28 of the generator 10.

FIGS. 7 and 9 illustrate features of an alternative embodiment of a fitting 200 which provides the means for eluent supply and eluate withdrawal. In this embodiment of the fitting 200, a lead bar 202 and a separate receptacle holder including needle adapter assembly 212 are joined on top of the casing 242 when the generator 10 is to be eluted. Lead bar 202 is provided on its underside with a boss or key 208 which is suitably an integral part of bar 202. The boss 208 has a curved surface 210 and a flat surface 211 at opposite ends to form a key which will mate with the keyway provided by the sidewalls 278 and 280 of the casing 242 to insure that the lead bar 202 can be mounted only in one position on the casing 242. The lead bar 202 may remain in place on the casing 242 to provide additional radiation shielding. The casing 242 and lead bar 202 are customarily retained at all times in a lead pig (not shown) having a cavity contoured to the shape of the casing 242 and lead bar 202 to provide additional radiation shielding. The top of the lead bar 202 is exposed when it is in place in the lead pig so that wells 204 and 206 are accessible to the needle adapter assembly of receptacle holder 212. The locator hole 213 in lead bar 202 in cooperation with the locating pin 215 of the receptacle holder 212 requires that assembly may be accomplished in only the correct position. Each of the wells 204, 206 includes a lug or key 217 on the inside wall to mate with keyways 219 of the needle shielding guides or plugs 221 when the receptacle holder 212 is mounted on the lead bar 202. These lugs 217 also provide means for retaining radiation shielding plugs (not shown) in the wells 204, 206 when the generator 10 is not being eluted. A rectangular cut out 223 near each corner of the lead bar 202 provides for the guides 225 which assist in assembling the receptacle holder 212 to the lead bar 202 and which may include lugs (not shown) to act as releasable fasteners to a protective plastic cover (not shown) which might be used over the lead bar 202 and lead pig (not shown). The slot 227 is provided as a means to secure the lead bar 202 to the lead pig (not shown).

The receptacle holder 212 shown in FIG. 7 and 9 is a unitary molded plastic holder for an eluent container (not shown) and an eluate container (not shown). The eluate container is preferably an evacuated vial and is inserted upside down into holder 230, after removal of protective cap 231, where double ended hypodermic needle 232 is positioned to pierce the closure of the eluate container. The needle 232 may include an intermediate filter 319 with associated lead shielding 320 and spring means 321 to hold it in place, and the bottom portion of the needle 232 is supported and centered by needle shielding guide or plug 221 mounted on the underside of holder 230 and which contains the collapsible needle shield 229. This needle shield 229 can be drawn down over the needle 232 to protect it when the receptacle holder 212 is not in use and is pushed out of the way into plug 221 when the receptacle holder 212 is mounted on the lead bar 202 and casing 242.

The receptacle holder 212 also includes holder 234 for an eluent container (not shown) which is inserted in an inverted position, after the removal of protective cover 235, so that needles 236 and 238 may pierce its closure. The needles 236 and 238 are supported within the holder 234. Needle 238 is a double ended hypodermic needle to conduct eluent into generator 10, and it is supported and centered by guide 221 and protected by needle shield 229 in the same manner as described above with respect to needle 232. Needle 236 serves to provide an inlet for air into the eluent container by connecting it to the atmosphere through conduit 242 and a hydrophobic filter 243.

The alternative embodiment of the fitting illustrated in FIGS. 7 and 9 includes as an optional but preferred feature the filter 319. This filter 319 is placed in the eluate collection line formed by conduit 20 and needle 232 and serves to further insure that the eluate collected from the generator 10 will be sterile and particle free and thereby suitable for immediate injection into a patient for diagnostic use. This filter 319 may be any suitable filter but is preferably a MIllipore filter, i.e., a microporous membrane filter composed of cellulose esters or similar polymeric materials, such as described in U.S. Pat. No. 3,386,585, issued June 4, 1968, or U.S. Pat. No. 3,471,019, issued Oct. 7, 1969, and manufactured by Millipore Corporation of Bedford, Massachusetts. A particularly desirable filter is a 0.22 micron Millipore filter in which part of the filter is hydrophobic. This filter has very good flow characteristics, and maintains good flow characteristics after the initial elution, i.e., on subsequent runs after the hydrophilic portion has already been wetted.

When the generator 10 is to be eluted with the embodiments of the casing 242 and fitting 200 illustrated in FIGS. 7 through 10, the technician removes lead plugs (not shown) from the two wells 204, 206 of the bar 202 in position on the casing 242 containing the generator 10. The locator pin 215 is aligned with the depression 213 and this permits the insertion of the needle shielding plugs 221 with needles 238 and 232 of the receptacle holder 212. The needles 238 and 232 pass down through the wells 204, 206 and pierce the covers 26, 28 of the inlet and outlet conduits 18, 20. When the eluent container and eluate container have been inserted into holders 234 and 230 to pierce their closures with the needles 236, 238 and 232, the elution will take place when a reduced pressure is present at the top of needle 232 in the eluate container. This reduced pressure is preferably obtained by the use of an evacuated vial as an eluate container. As elution proceeds, eluent is drawn through needle 238 into and through inlet conduit 18, through the alumina in generator 10 where it picks up the Tc.sup. 99m, to the bottom of generator 10 where it passes into and through outlet conduit 20, through the bottom portion of needle 232, through the filter 319 which interrupts needle 232, through the balance of needle 232 and into the eluate container.

At no time is this system rendered vulnerable to the inflow of contaminents nor does it permit leakage of the emissive fluids. The system is simple to assemble, there being little room for error in aligning the parts. All concerned parties are adequately protected from emission until the preparation is withdrawn for injection.

Many changes may be made in the details of the instant invention, in the method and materials of fabrication, in the configuration and assemblage of the constituent elements without departing from the spirit and scope of the appended claims, which changes are intended to be embraced therewithin .

Claims

What is claimed is:

1. A generator for sterile, elutable radioactive material which comprises a hollow column containing elutable radioactive material, said column including inlet and outlet ports which are each in communication with one end of inlet and outlet conduits respectively, the other ends of said conduits being terminated by pierceable closure caps, which caps prevent the inflow of contaminents through said conduits, said column, inlet and outlet conduits and caps being embedded in a casing adapted to permit the caps to be pierced, a fitting adapted to be joined to said casing, means to properly align said fitting on said casing to effect joinder therebetween, said fitting including means to pierce said caps, and said fitting including means in communication with said piercing means for the cap on said inlet conduit to connect a container of eluent, said eluent being passable through said inlet conduit into said column, means in communication with said piercing means for the cap on said outlet conduit to connect a collecting container for eluate to said fitting, and means to establish a pressure differential between said eluent and collecting containers causing the eluent to flow through said conduits and into said collecting container.

2. The generator of claim 1 wherein the means to join said casing and said fitting in proper alignment comprise a boss on said fitting adapted to be received in an opening in said casing, a guide segment connected to said boss and a mating segment connected to said casing, whereby said fitting and said casing can be joined only when said segments are mated.

3. The generator of claim 1 wherein said casing is formed of vertically split sections, each section including appropriate interior depressions to accommodate said conduits and said column therein.

4. The generator of claim 3 wherein said split sections include spaced interior ribs and grooves, there being only one position in which respective grooves and ribs are matable.

5. The generator of claim 1 including needles, depending from each of said means to connect said container of eluent, and said means to connect said collecting container, each adapted to pierce the respective caps, thereby to define a complete fluid flow path between said eluent and said collecting containers.

6. The generator of claim 1 including means to admit air into said eluent container upon the evacuation of the eluent therefrom.

7. The generator of claim 1 wherein the means to establish a pressure differential between said eluent and collecting containers is an evacuated eluate collecting container.