Abstract:
The disposable polymer-structured filtering kit includes a disposable, polymer-structured filtering funnel with a stem having a distal tip. A flow discharge end is formed at the distal tip. Preferably, a polymer fritted filter disc is positioned in the funnel, providing filtering for liquids passing therethrough. The kit preferably also includes a glass vacuum take-off adapter having a port for connecting to a vacuum source for providing negative pressure. The adapter securely and snuggly receives the funnel and maintains position of the distal tip thereof with the flow discharge end below the port, thus preventing contaminants from entering the adapter. A reusable, glass round bottle flask or a disposable vial receives the adapter and the stem of the funnel. The funnel and fritted disc are formed from disposable materials, thus removing the necessity of cleaning them following use. The adapter is reusable, since no contaminants come in contact therewith during filtering.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/136,141, filed Aug. 14, 2008. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to laboratory glassware, and particularly to a disposable polymer-structured filtering kit for use in small-scale vacuum filtration of solid-liquid samples. 
         [0004]    2. Description of the Related Art 
         [0005]    Vacuum filtration, a common technique used in chemistry laboratories, involves passing a liquid containing a solid through a porous interface so that the solid can be trapped as the liquid flows therethrough. Typically, a vacuum filtration kit for small-scale filtration includes a filter funnel, an adapter and a receiving receptacle. 
         [0006]    A typical vacuum filtration kit using the above three components has a vacuum port formed through the filter funnel. Such a kit typically includes a glass filter funnel with a vacuum take-off port connected to a vacuum source and a glass filtrate receptacle for receiving the solution. The funnel typically has a ground joint for coupling with a filtrate receptacle, and has a fritted glass filter disc for filtering any insoluble materials. 
         [0007]    Another typical vacuum filtration kit may have a vacuum take-off port integrated into the adapter. The kit includes a glass filtering funnel without a ground joint, the glass adapter with the vacuum take-off port, a rubber adapter for coupling with the funnel, and a receptacle for receiving filtrate. 
         [0008]    In yet another typical vacuum filtration kit, a vacuum take-off port is integrated into a filtrate receptacle. The kit includes a filtering funnel, the filtrate receptacle with the vacuum take-off port, and a rubber adapter for coupling the funnel with the filtrate receptacle. 
         [0009]    With each of these vacuum filtration kits, during the filtration process, the fluid to be filtered is placed into the funnel and the filtrate receptacle is attached. Negative pressure from the vacuum is applied to the vacuum take-off port. The pressure differential caused by the vacuum causes the fluid to pass through the filter and into the receptacle. Thus, the insoluble material is collected on the fritted disc. 
         [0010]    Following usage, all of the components of the vacuum filtration kit must be cleaned in order to eliminate contamination. However, the glassware is susceptible to accidental breakage and shattering during the cleaning process, particularly since some of the components are difficult to clean by hand. Some of the above components are relatively expensive to replace, particularly the glass filter funnel with the glass fritted disc filter, because these are typically made by hand. Additionally, the cleaning process is quite time consuming, particularly when viewed in the laboratory setting, where time is an important factor in many experiments. Thus, a disposable polymer-structured filtering kit solving the aforementioned problems is desired. 
       SUMMARY OF THE INVENTION 
       [0011]    In a first embodiment, the disposable polymer-structured filtering kit includes a disposable, polymer-structured filtering funnel with a stem having a distal tip. A flow discharge end is formed at the distal tip. Preferably, a polymer fritted filter disc is positioned in the funnel, providing filtering for liquids passing therethrough. The kit preferably also includes a glass vacuum take-off adapter having a port for connecting to a vacuum source for providing negative pressure. The adapter securely and snuggly receives the funnel and maintains position of the distal tip thereof with the flow discharge end below the port, thus preventing contaminants from entering the adapter. A reusable, glass round bottle flask receives the adapter and the stem of the funnel. The funnel and fritted disc are formed from disposable materials, thus removing the necessity of cleaning them following use. The adapter does not need to be cleaned and can be reused, since no contaminants come in contact therewith during filtering. The kit is well adapted for collecting either filtrate or insoluble material. 
         [0012]    In an alternative embodiment, the disposable, polymer-structured filtering kit includes a disposable, polymer-structured filtering funnel with a stem having a distal tip. A flow discharge end is formed at the distal tip. The funnel also preferably has a relatively wide top opening for easily receiving a liquid sample. A polymer fritted filter disc is also positioned in the funnel to provide filtering. The kit further includes a screw-threaded joint adapter having a port for connection to a vacuum source to provide negative pressure. The adapter securely and snuggly receives the funnel and maintains position of the distal tip thereof with the flow discharge end below the port, thus preventing contaminants from entering the adapter. 
         [0013]    A disposable glass screw-threaded receiving vial is coupled to the adapter by the screw-threaded joint. The vial further receives the stem of the funnel, with the flow discharge end thereof being positioned in the vial. The funnel and fritted disc are formed from disposable materials, thus removing the necessity of cleaning them following use. The vial may also be unscrewed from the adapter for disposal. The adapter does not need to be cleaned and can be reused, since no contaminants come in contact therewith during filtering. 
         [0014]    In a further alternative embodiment, the disposable polymer-structured filtering kit includes a disposable polymer-structured filtering funnel. The funnel has a detachable stem with a distal tip, a relatively wide top opening for easily receiving a liquid sample, and a flow discharge end positioned at the distal tip. The kit further includes a polymer adapter for securely and snuggly receiving the funnel and positioning the distal end thereof (with the flow discharge end) below the adapter. A polymer fritted filter disc is positioned between the funnel barrel and funnel base to provide filtering. An Erlenmeyer filtering flask having a vacuum port receives the adapter and the stem of the funnel, with the flow discharge end being positioned in the flask beyond the port. As above, the funnel and fritted disc are formed from disposable materials, thus removing the necessity of cleaning them following use. Further, the adapter does not need to be cleaned and can be reused, since no contaminants come in contact therewith during filtering. As a further alternative, a kit may be provided including a disposable polymer-structured filtering funnel, a glass vacuum take-off adapter, and reusable glass flask or disposable vial, as described above. The funnel, adapter and flask or vial may have any of the above-described configurations, but with the flask or vial being positioned within the adapter, rather than beneath it, as in the previous embodiments. 
         [0015]    These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective view of a disposable polymer-structured filtering kit according to the present invention. 
           [0017]      FIG. 2  is a perspective view of an alternative embodiment of the disposable polymer-structured filtering kit according to the present invention. 
           [0018]      FIG. 3  is a perspective view of another alternative embodiment of the disposable polymer-structured filtering kit according to the present. 
           [0019]      FIG. 4  is a side view of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit of  FIG. 1 . 
           [0020]      FIG. 5  is a side view of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit of  FIG. 2 . 
           [0021]      FIG. 6  is a partially exploded, perspective view of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit of  FIG. 3 . 
           [0022]      FIG. 7  is a side view of a vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 1 . 
           [0023]      FIG. 8  is a partially exploded view of a vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 2 . 
           [0024]      FIG. 9  is a partially exploded view of an alternative vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 1 . 
           [0025]      FIG. 10  is a partially exploded view of an alternative vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 2 . 
           [0026]      FIG. 11  is a side view of a polymer adapter of the disposable polymer-structured filtering kit of  FIG. 3 . 
           [0027]      FIG. 12  is a partially exploded side view of an alternative polymer adapter of the disposable polymer-structured filtering kit of  FIG. 3 . 
           [0028]      FIG. 13  is a side view of a disposable glass-receiving receptacle of the disposable polymer-structured filtering kit of  FIG. 2 . 
           [0029]      FIG. 14  is a side view of an alternative embodiment of a vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 1  having a straight vacuum arm and a stopcock disposed in the arm. 
           [0030]      FIG. 15  is a partially exploded view of another alternative embodiment of a vacuum take-off adapter of the disposable polymer-structured filtering kit of  FIG. 2  having a straight vacuum arm and a stopcock disposed in the arm. 
           [0031]      FIG. 16  is a side view of an alternative embodiment of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit according to the present invention, the funnel being conical and having a fritted filter disk or a polymer disk supported by an annular flange in the funnel bowl. 
           [0032]      FIG. 17  is a side view of another alternative embodiment of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit according to the present invention, the funnel being conical and having a polymer plate disposed in the funnel bowl. 
           [0033]      FIG. 18  is a side view of another alternative embodiment of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit according to the present invention, the funnel being cylindrical and having a fritted filter disk or polymer disk supported by an annular flange in the funnel bowl. 
           [0034]      FIG. 19  is a perspective view of another alternative embodiment of a disposable polymer-structured filter funnel of the disposable polymer-structured filtering kit according to the present invention, the funnel being cylindrical and having a polymer plate disposed in the funnel bowl. 
           [0035]      FIG. 20  is a plan view of an alternative embodiment of a filter disc of the disposable polymer-structured filtering kit according to the present invention, showing the hole pattern. 
           [0036]      FIG. 21  is a plan view of another alternative embodiment of a filter disc of the disposable polymer-structured filtering kit according to the present invention, showing a pattern of slits or slots. 
           [0037]      FIG. 22  is a side view of another alternative embodiment of the disposable polymer-structured filtering kit according to the present invention. 
       
    
    
       [0038]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]    The present invention relates to disposable polymer-structured filtering kits. The kits, as will be described in detail below, each include disposable polymer-structured filter funnels, non-disposable adapters, and glass receptacles. 
         [0040]    With reference to  FIG. 1 , a first embodiment of the disposable polymer-structured filtering kit, generally indicated by numeral  100 , is shown. The kit  100  includes a disposable polymer-structured filtering funnel  110 , a glass vacuum take-off adapter  112 , and reusable glass round bottle flask  114 . 
         [0041]    The funnel  110  has a stem  115  which, as shown, is relatively long and has a flow discharge end  116  formed at the distal tip thereof. The stem  115  is relatively long such that the flow discharge end  116  extends past the glass vacuum take-off adapter  112  and into the reusable glass round bottle flask  114 , as shown. The flow discharge end  116  extends into the flask  114  so as to prevent contamination of adapter  112  by filtrate when under negative pressure from an attached vacuum source (not shown). The polymer fritted filter  119  is placed on the bottom of the barrel  118  of funnel  110  for trapping insoluble materials. The funnel  110  further includes an inner joint  117  positioned between the stem  115  and barrel  118 . The inner joint  117  provides a snug and secure fit between the funnel  110  and the adapter  112 . 
         [0042]    The glass vacuum take-off adapter  112  has a vacuum take-off port  120  for connection to the vacuum source, a funnel ground joint  122 , and a bottom flask ground joint  124 . The funnel ground joint  122  receives the stem  115  of the funnel  110  and the inner joint  117  of the funnel  110  fits the funnel ground joint  122 . The stem  115  passes through the bottom flask ground joint  124  and is positioned such that the flow discharge end  116  is received within the flask  114 , as shown. The flask  114  is a commonly used receptacle in chemistry laboratories, and it should be understood that the contouring and relative dimensions of flask  114  are shown for exemplary purposes only. 
         [0043]    After filtration is complete, the funnel  110  is removed, safely discarded and disposed of, and replaced with another disposable polymer-structured filtering funnel. The adapter  112  does not need to be replaced, as the length of the stem  115  of the funnel  110  positions the distal end of the flow discharge end  116  within the flask  114 , past the vacuum take-off port  120 , thus removing the risk of contamination during filtration. The flask  114  is cleaned and may be reused. 
         [0044]      FIG. 2  illustrates an alternative embodiment of the disposable polymer-structured filtering kit, generally indicated by numeral  200 . The kit  200  includes a disposable polymer-structured filtering funnel  210 , a screw-threaded joint adapter  212 , and a removable and disposable glass screw-threaded receiving vial  214 . 
         [0045]    Funnel  210  has a stem  215  that is relatively long, as shown, with a flow discharge end  216  formed at the distal tip thereof. As in the previous embodiment, the stem  215  is long so that the flow discharge end  216  extends past the screw-threaded joint adapter  212  and into the disposable glass screw-threaded receiving vial  214 . The flow discharge end  216  extends into the vial  214  such that the adapter  212  is not contaminated by filtrate when under negative pressure generated by the vacuum source. The polymer fritted filter disc  219  is placed on the bottom of the barrel  218  for trapping any insoluble materials. The funnel  210  further includes an inner joint  217  formed between the stem  215  and barrel  218 . The inner joint  217  provides a snug and secure fit between the funnel  210  and the adapter  212 . The funnel  210  also preferably has a relatively wide top opening  225 , allowing for easy insertion therein of the liquid sample. 
         [0046]    The screw-threaded joint adapter  212  includes a vacuum take-off port  220  for connecting to the vacuum source for providing negative pressure, along with a funnel ground joint  222  and a bottom vial joint  224 . The bottom vial joint  224  is threaded to releasably screw on to the adapter  212  and the vial  214 . 
         [0047]    The funnel ground joint  222  receives the stem  215  of the funnel  210 , and the inner joint  217  of the funnel  210  fits the funnel ground joint  222 . The stem  215  passes through the bottom vial joint  224  such that the flow discharge end  216  is positioned within the vial  214 . The vial  214  is preferably disposable. 
         [0048]    Following filtration, the funnel  210  is removed, safely discarded and disposed of, and replaced with another disposable polymer-structured filtering funnel. The adapter  212  does not need to be replaced, because the length of the stem  215  of the funnel  210  positions the flow discharge end  216  thereof within vial  214 , thus placing end  216  past the vacuum take-off port  220 . The vial  214  may be easily removed, because it is removably screwed on to the adapter  212 , and may be discarded. The kit  200  is preferred for either taking filtrate or taking insoluble materials that are collected by the fritted disc  219 . 
         [0049]    With reference to  FIG. 3 , a further alternative embodiment of the disposable polymer-structured filtering kit, generally indicated by numeral  300 , is shown. The kit  300  includes a disposable polymer-structured filtering funnel  310 , an adapter  312 , and an Erlenmeyer shaped filtering flask  314  with a vacuum port  320 . 
         [0050]    A funnel base  321  (best seen in  FIG. 6 ) has a stem  315  that is relatively long with a flow discharge end  316  formed at the distal tip. As in the previous embodiments, the stem  315  is long so that the flow discharge end  316  extends past the adapter  312 , into the Erlenmeyer shaped filtering flask  314 , and past the vacuum port  320  of the flask  314 . The flow discharge end  316  extends past the vacuum port  320  such that the filtrate does not contaminate the adapter  312  during vacuum filtration. The funnel base  321  further includes an inner joint  317  at the top of the stem  315 . The inner joint  317  provides a snug fit with the adapter  312 . The funnel  310  also preferably has a relatively wide top opening  325 , for easy reception of the liquid sample. Additionally, a clamp  327  is preferably provided for holding the funnel barrel  318  to the funnel base  321 , with the polymer fritted filter disc  319  being positioned therebetween. 
         [0051]    The adapter  312  has a glass funnel ground joint  322  and a polymer stopper joint  324 . The glass funnel ground joint  322  receives the stem  315  of the funnel  310 , and the inner joint  317  of the funnel  310  fits the funnel ground joint  322 . The stem  315  then passes through the polymer stopper joint  324  and is positioned such that the flow discharge end  316  is located below the vacuum port  320  of the flask  314 . 
         [0052]    After filtration is complete, the funnel  310  is removed, safely discarded and disposed of, and replaced with another disposable polymer-structured filtering funnel. The adapter  312  does not need to be replaced, because the length of the stem  315  of the funnel  310  and the positioning of the distal end of the flow discharge end  316  within flask  314  is positioned beyond the vacuum take-off port  320  of the flask  314 , thus preventing contamination of adapter  312 . Fritted disc  319  can similarly be disposed of. The kit  300  is preferred for taking insoluble materials that are collected by the fritted disc  319 , since the funnel  310  can be disassembled so that the solid materials are easily removed. 
         [0053]      FIG. 4  better illustrates the disposable polymer-structured filter funnel  110  of  FIG. 1 . The disposable filter funnel  110  is preferably barrel-shaped, having an open upper end  125  and a lower stem  115  having a flow discharge end  116 . Funnel  110 , formed from a low cost polymer material, and fritted filter disc  119  are both disposable and may be easily replaced. 
         [0054]    The filtering funnel  110  and fritted filter disc  119  must resist corrosion from various organic solvents. Accordingly, an inexpensive polypropylene is preferably selected as the material of funnel  110 . However, other polymer materials may also be utilized, such as acrylic, polycarbonate, styrene, polyfluoroethylene, polyvinylidene fluoride, or polyethylene. The minimum length of the stem  115 , to position the flow discharge end  116  within flask  114 , is preferably approximately twenty mm. The preferred length for the stem  115  is approximately eighty mm. The top end of the stem  115  includes inner joint  117 , which fits the funnel ground joint  122  of the glass adapter  112  tightly to prevent leaking. The size of inner joint  117  is preferably between approximately five and sixteen mm in diameter, and between approximately five and twenty mm in length. It should be understood that the funnel  110  may be used in combination with the filtering kits of  FIGS. 2 and 3 . An exemplary internal volume for  110  is approximately 40 mL. 
         [0055]      FIG. 5  illustrates the disposable polymer-structured filter funnel  210  of  FIG. 2 . Funnel  210  preferably has a relatively wide top opening  225 , as shown, and has contouring and dimensions similar to those described above with regard to funnel  110 . However, barrel  218  has an open upper end  225 . The top end of the stem  215  has an inner joint  217 , which fits the funnel ground joint  222  of the glass adapter  212  tightly to prevent leaking. The size of inner joint  217  is preferably between five and sixteen mm in diameter, and from between five and twenty mm in length. It should be understood that the funnel  210  may be used in combination with the filtering kits of  FIGS. 1 and 3 . As noted above, funnel  210  is designed for relatively small quantities of fluid. The exemplary internal volume for funnel  110  is given above as being approximately 40 mL. A corresponding exemplary internal volume for funnel  210  is 18 mL. It should be understood that the funnels may have any desired dimensions, or be provided in sets of varying sizes, dependent upon the particular needs of the user. 
         [0056]      FIG. 6  illustrates the disposable polymer-structured filter funnel  310  for trapping solid samples of  FIG. 3 . The barrel  318  has an open top end  325  and an open bottom end  328 . The barrel  318  uses a wider open end  325  (similar to that described above with regard to upper end  225  of funnel  210 ) for transferring relatively small volumes of fluid samples. The open bottom end  328  is provided for easily removing solid samples from the funnel  310 . 
         [0057]    A concavity  329  is formed at the top end of the funnel base  321 , as shown. The filter disc  319  is placed in the concavity  329 , enclosing the filter disc  319  when the kit is assembled. The metal clamp  327  is used to tightly clamp bottom end  328  of the barrel  318  and the top end of the base  321 . As shown, the barrel  318  forms an upper portion of the funnel, with the stem  317  forming a detachable lower portion. This arrangement is adapted for trapping solid samples and transferring relatively small volumes of liquid samples. It should be understood that the funnel  310  may be used in combination with the filtering kits of  FIGS. 1 and 2 . Preferably, filter discs  119 ,  219  and  319  are formed from a polymer material, such as polyethylene, for example, having a relatively coarse or medium porosity. Alternatively, a conventional glass fritted filter disc may also be utilized. 
         [0058]      FIG. 7  illustrates the vacuum take-off adapter  112 , with a bottom flask ground joint  124  and the funnel ground joint  122 , of  FIG. 1 . The vacuum take-off port  120  is formed on the side of adapter  112  for connection to the vacuum source. The funnel ground joint  122  on the top end is coupled with inner joint  117  of the funnel  110 , and is preferably between approximately five and sixteen mm in diameter, and between five and twenty mm in length. The bottom flask ground joint  124  coupled with the receiving receptacle or flask  114  preferably is manufactured in sizes of 14/20, 19/22, 24/25, 24/40 or 29/42. As is conventionally known, a size of 14/20, for example, means, that the bottom flask ground joint  124  is fourteen mm in diameter, and twenty mm in length. The bottom ground joint  124  fits reusable glass round bottle flasks, such as exemplary flask  114  of  FIG. 1 . Adapter  112  is preferably formed from conventional glass, though, alternatively, may be formed from a polymer material, metal or any other suitable material.  FIG. 14  illustrates an alternative embodiment of adapter  112  in which stopcock or valve  121  may be integrated into the vacuum take-off port  120  in order to adjust the vacuum and prevent the filtrate from being sucked into the vacuum line. 
         [0059]      FIG. 8  illustrates the vacuum take-off adapter  212 , with a bottom vial joint  224  and the funnel ground joint  222 , of  FIG. 2 . The vacuum take-off glass adapter  212 , which is designed for coupling with disposable glass vial  214 , is shown joined to vial  214  in  FIG. 2 . The adapter  212  includes funnel ground joint  222  on its top end, a bottom vial joint  224  on its bottom end, and a vacuum take-off port  220  projecting from its side. The funnel ground joint  222  fits the inner joint  217  of the funnel  210 , and is preferably between five and sixteen mm in diameter, and between five and twenty mm in length. The bottom vial joint  224  has a top threaded joint  226  for screwing to the glass adapter  212 , having threads  228 , and a bottom threaded joint  227  for screwing to the disposable glass vial  214 , as shown in  FIG. 2 . The thread of the joint  226  preferably uses G.P.I. (Glass Packaging Institute) 20-400 thread. The inside diameter of the threaded joint  226  is approximately twenty mm. The numeral “400” designates a specific style of the finish.  FIG. 15  illustrates an alternative embodiment of adapter  212 . As shown, a stopcock or valve  221  may be integrated into the vacuum take-off port  220  in order to adjust the vacuum and prevent the filtrate from being sucked into the vacuum line. Adapter  212  is preferably formed from conventional glass, but may alternatively be formed from polymer materials, metal or any other suitable material. 
         [0060]      FIG. 9  illustrates an alternative vacuum take-off adapter  412 , for use with the kit of  FIG. 1 , with a bottom ground joint  424  and a filter funnel screw-threaded joint  422 . The glass adapter  412  can replace adapter  112 . The adapter  412  has an interface screw-threaded joint  436  on its top end, with an inner diameter between approximately five and sixteen mm. A cap  438 , having an aperture formed therethrough, and a sealing ring  439  are placed on the interface screw-threaded joint  436  to seal an attached filter funnel, which functions to adjust a position of a flow discharge end of the funnel. A vacuum take-off port  420  is further provided. 
         [0061]      FIG. 10  illustrates an alternative vacuum take-off adapter  512 , for use with the kit of  FIG. 2 , having a bottom vial joint  524  and a funnel screw threaded joint  522 . A side vacuum port  520  extends outwardly, as shown. The adapter  512  includes a funnel screw-threaded joint  536  on its top end. To connect the adapter  512  to a funnel, a cap  538 , having an aperture formed therethrough, is provided for receiving a flow discharge end of the funnel, and positioning the flow discharge end beneath the side vacuum port  520 . A sealing ring  539  and the cap  538  are placed on the funnel screw-threaded joint  536  to seal an attached funnel. The bottom vial joint  524  has an interface screw-threaded joint  526  that attaches to the adapter  512  by threads  528 , and a vial screw-threaded joint  527  for coupling with a receiving receptacle or vial. 
         [0062]      FIG. 11  illustrates adapter  312  of the kit of  FIG. 3 . Adapter  312  includes a stopper  324  having an aperture formed centrally therethrough. The adapter  312  is designed for coupling with a vacuum Erlenmeyer shaped filtering flask, such as exemplary flask  314  of  FIG. 3 . The stopper  324  is formed from a polymer material, such as rubber, silicone rubber or neoprene. Glass tubing  330 , with funnel ground joint  322  formed on its top end, is inserted tightly into the center of the stopper  324 . The glass funnel ground joint  322  has a diameter between approximately five and sixteen mm, and a length between approximately five and twenty mm. 
         [0063]      FIG. 12  illustrates an alternative adapter  612 , for use with the kit of  FIG. 3 , with a screw-threaded joint  622  on its top end. The stopper  624  is formed from polymer materials, such as rubber, silicone rubber or neoprene and is similar to stopper  324  except for the screw-threaded joint  622 . The adapter  612  is used to couple a filter funnel with the vacuum Erlenmeyer shaped filtering flask. A glass screw threaded tube  630  is inserted tightly into the center of the stopper  624 . A cap  638 , having an aperture formed therethrough and a sealing ring  639 , are placed on a screw-threaded top  636  of the adapter  612  to seal an attached filter funnel. Thus, the flow discharge end of the funnel is positioned below the vacuum take-off port when the kit is assembled. 
         [0064]      FIG. 13  illustrates the disposable glass-receiving receptacle  214  of  FIG. 2 . Receptacle  214  includes a screw-threaded joint  230 . The diameter of the threaded joint  230  is preferably between twenty and thirty mm. A typical diameter of the joint  230  is approximately twenty-three mm, fitting G.P.I. 20-400 thread. The vial  214  has a semi-round bottom to prevent cracking under negative or positive pressure. The volume of the vial  214  is preferably between 60 and 300 mL. Multiple vials having differing volumes may be provided, such as an 100 mL vial and a 200 mL, for example. 
         [0065]      FIG. 16  illustrates an alternative cone-shaped disposable filter funnel  610 , to be used with any of the kits of  FIG. 1 ,  2  or  3 . Funnel  610  includes an upper portion  602 , having a substantially frusto-conical contour, with a long stem  615  projecting downwardly therefrom. The upper portion  602  has an open upper end  625 , and an annular flange  604  is formed within the upper portion  602 , adjacent the junction between the lower end of upper portion  602  and the stem  615 , as shown. Filter disc  619  is removably received by annular flange  604 , as shown. As described above, filter disc  619  may be formed from a disposable, porous polymeric material, or may be formed from fritted glass or the like. As a further alternative, the filter disc  619  may be formed as a polymer disc.  FIG. 20  illustrates exemplary polymer disc  619 , having a main body  700  with a plurality of relatively small apertures or pores  706  formed therethrough. Polymer disc  619  is covered in disposable filter paper or a porous, polymeric membrane in order to trap the solute or insoluble materials.  FIG. 21  illustrates an alternative polymer disc  819  having a main body  800  and a plurality of slots  802  formed in an upper surface thereof. A central aperture or pore  804  is further formed therethrough. 
         [0066]      FIG. 17  illustrates an alternative cone-shaped disposable filter funnel  710 , similar to funnel  610  described above. Funnel  710  includes an upper portion  702 , having a substantially frusto-conical contour, with a long stem  715  projecting downwardly therefrom. The upper portion  702  has an open upper end  725 . Instead of the annular flange  604  of funnel  610 , the filter disc  719  is formed integrally with the upper portion  702 , as shown. 
         [0067]      FIG. 18  illustrates a further alternative filter funnel  810 , to be used with any of the kits of  FIG. 1 ,  2  or  3 . Funnel  810  includes a substantially cylindrical upper portion  802  with a long stem  815  projecting downwardly therefrom. The upper portion  802  has an open upper end  825 , and an annular flange  804  is formed within the upper portion  802 , adjacent the junction between the lower end of upper portion  802  and the stem  815 , as shown. Filter disc  619  is removably received by annular flange  804 , as shown. As described above, filter disc  619  may be formed from a disposable, porous polymeric material, or may be formed from fritted glass or the like. Filter disc  619  may, alternatively, be replaced by filter discs  719  or  819 , as desired. As a further alternative, the filter disc  619  is wrapped in disposable filter paper. 
         [0068]      FIG. 19  shows an alternative filter funnel  850 , similar in contour to filter funnel  810 , described above, but lacking the inner, annular flange  804 . Funnel  850  includes a lower, stem portion  860  and an upper portion  862 , having an open, upper end  855 . A filter disc, such as filter disc  719 , described above, for example, is received within the upper portion  862  and the filter funnel  850  and/or the filter disc  719  are sized such that the filter disc  719  mates with the inner circumferential wall of the funnel  850  at or near the junction between the upper portion  862  and the lower portion  860 . The filter disc  719  is held in place by frictional engagement with the inner wall. Filter disc  719  may, alternatively, be replaced by filter discs  819 , as desired. As a further alternative, the filter disc  719  is wrapped in disposable filter paper. 
         [0069]    With reference to  FIG. 22 , another embodiment of the disposable polymer-structured filtering kit, generally indicated by numeral  1000 , is shown. The kit  1000  includes a disposable polymer-structured filtering funnel  1010 , a glass vacuum take-off adapter  1012 , and reusable glass flask or disposable vial  1014 . Funnel  1010 , adapter  1012  and flask or vial  1014  may have any of the above-described configurations, as  FIG. 22  is intended to illustrate an alternative where flask or vial  1014  is positioned within adapter  1012 , rather than beneath it. 
         [0070]    As in the previous embodiments, the funnel  1010  has a stem  1015  with a flow discharge end  1016  formed at the distal tip thereof. The stem  1015 , however, extends within the glass vacuum take-off adapter  1012  and into the reusable flask or disposable vial  1014 . The flow discharge end  1016  extends into the flask  1014  to prevent contamination of adapter  1012  by filtrate when under negative pressure from an attached vacuum source (not shown). A polymer fritted filter  1019  is placed on the bottom of the barrel  1018  of funnel  1010  for trapping insoluble materials. The funnel  1010  further includes an inner joint  1017  positioned between the stem  1015  and barrel  1018 . The inner joint  1017  provides a snug and secure fit between the funnel  1010  and the adapter  1012 . 
         [0071]    The glass vacuum take-off adapter  1012  has a vacuum take-off port  1020  for connection to the vacuum source, and a funnel ground joint  1022 . A cap  1025 , formed from a polymer material, is further provided for sealing the adapter. The funnel ground joint  1022  receives the stem  1015  of the funnel  1010  and the inner joint  1017  of the funnel  1010  fits the funnel ground joint  1022 . Rather than the bottom flask ground joint of the previous embodiments, a tube  1024  is provided within the adapter  1012 , as shown, at the upper end thereof, so that stem  1015  passes through the tube  1024  and is positioned so that the flow discharge end  1016  is received within the flask or vial  1014 . Glass tube  1024 , with funnel ground joint  1022  on its top end, are inserted tightly through the center of cap  1025 . The flask or vial  1014  is a commonly used receptacle in chemistry laboratories, and it should be understood that the shape and relative dimensions of flask  1014  are shown for exemplary purposes only. The glass funnel ground joint  1022  preferably has a diameter between approximately five and sixteen mm, and a length between approximately five and twenty mm. 
         [0072]    After filtration is complete, the funnel  1010  is removed, safely discarded and disposed of, and replaced with another disposable polymer-structured filtering funnel. The cap  1025  of adapter  1012  is also opened to remove the flask or vial  1014 . The adapter  1012  does not need to be replaced, as the length of the stem  1015  of the funnel  1010  positions the distal end of the flow discharge end  1016  within the flask or vial  1014 , thus removing the risk of contamination during filtration. 
         [0073]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.