Abstract:
A container for holding fluids in isolation includes an outer container and two deformable inner containers carried within the internal space of the outer container. The outer container is provided with a view port enabling the user to visually examine the inner containers. The inner containers have respective ports communicating with their interiors. As fluid is withdrawn from the first inner container its volume is reduced so that the second container may receive a like amount of fluid. The second inner container may hold colorants or absorbents. The container may be used with various chemical applications, such as high performance liquid chromatography or fluid injection analysis, wherein supply fluid is withdrawn from the first inner container, used, and returned as waste fluid to the second inner container so that the overall volume of fluids remains relatively constant.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention pertains to a dispensing collection system that can be used to transport and store fluids and, more particularly, to a container for holding a plurality of fluids in isolation. 
     2. Background Art 
     Many processes employ liquids, solutions, solvents and other chemical fluids that need to be delivered and, after use, need to be discarded. Illustrative of one specific application that requires a source of supply liquid and produces waste liquid is liquid chromatography, such as high performance liquid chromatography (HPLC). Another application is fluid injection analysis (FIA) used in conducting continuous, high-throughput titrations, colorimetric analyses, enzymatic assays, and the like. Other applications that might require relatively large volumes of supply liquid and generate a similar volume of waste liquid are material scrubbing or washing applications, electroplating, and other similar processes. 
     HPLC technology is widely used to detect and identify different components contained in a test sample. Typical HPLC instruments use a high-pressure pump for forcing a suitable solvent, via capillary lines, at a controlled flow rate serially from a reservoir (usually a glass or plastic bottle), through a separation column and a UV or other type detector, and exhausting all fluids to a waste reservoir. The column contains an absorbent selected for components anticipated to be in the test samples. During a HPLC analysis run, a small quantity of the test sample injected into the flow of the pressurized solvent will travel into and through the separation column. The different subphase sample components pass through the column at different rates, each thereby becoming substantially isolated before passing the detector for individual identification. 
     Typical solvent (also called mobile phase) used in HPLC is a mixture of water with alcohols or acetonitrile (MeCN). Alternatively, the mobile phase can be a mixture of hexane with alcohols or other polar solvents. Different ionic modifiers (salts, acids, bases) also constitute mobile phase in small concentrations. This mobile phase is typically prepared by the HPLC instrument user prior to setting up for an HPLC analysis. Stages involved in mobile phase preparation include measuring of volume of all liquid ingredients, weighing all solid ingredients, dissolving and mixing of all components, adjusting pH if needed with acid or base monitoring by pH meter, filtering obtained solution, and removing dissolved gasses by inert gas purging or by vacuum. Typically, all of the steps are recorded in a laboratory notebook. After analysis is complete, the used mobile phase accumulated during the run is disposed of. All of these steps take time to complete and require an experienced technician to perform. Further, any errors in preparing for the run can be costly. 
     Similarly, chemical analysis using FIA includes a pump for effecting flow of a non-segmented, continuous carrier of suitable liquid from a supply reservoir through a tube. An injection port is provided along the tube for placing a measured amount of sample into the moving liquid stream. As the sample moves downstream through the tube and an optional reactor, radial and convection diffusion disperse and mix the sample with reagents or other components. Thereafter, the liquid zone containing the sample passes through a suitable detector and finally is deposited in a waste reservoir. Detectors often used in FIA include colorimeters, fluorometers, ion-selective electrodes, or biosensors that continuously detect changes in absorbance, electrode potential, or other measurable physical parameters. 
     If one is analyzing a high number of samples by these types of procedures, the amount of supply liquid required can be significant and preparation therefore requires either high volume or multiple repetitions. It is logical then for high volume analysis laboratories to contract out the preparation of such liquids. In addition, any waste liquid must be properly disposed of. 
     While the use of glass and plastic bottles in the prior art as a reservoir for unused and used liquids is sufficient for their intended function, other constructions may provide features that are more desirable and convenient for a user. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to overcoming one or more of the problems as set forth above. 
     It is an object of the present invention to provide a single container that can be used to deliver fluid supply and take away used or waste fluid. 
     In one aspect of the invention, a container for holding multiple fluids in isolation includes an outer container of predetermined volume and at least two variable-volume inner containers, one for supply fluid and one for waste fluid. 
     In another aspect of the invention, the inner container for supply fluid is deflatable and the inner container for waste fluid is expandable. 
     In a further aspect of the invention, the outer container defines a predetermined volume and the inner containers together define a second volume that is substantially the same as the first volume as fluid is simultaneously withdrawn from one inner container and returned to the other inner container. 
     In yet another aspect of the invention, each of the inner containers includes a port providing communication with the internal chamber defined by each container and each port is adapted to receive a flow line for moving fluid to or from the interior of the respective inner containers. 
     In a further aspect of the invention, a view port is provided in the outer container enabling a user to visually ascertain the fluid levels in at least one of the inner containers. 
     In another aspect of the invention, a colorant is provided in one container enabling a user to more clearly see fluid levels in the container as it is being filled and the other emptied. 
     In another aspect of the invention, an absorbent is provided in one container to create a solid or semi-solid to minimize possible fluid leakage and to enable the container to be more securely transported and disposed of. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The details of construction and operation of the invention are more fully described with reference to the accompanying drawings which form a part hereof and in which like reference numerals refer to like parts throughout. 
       In the drawings: 
         FIG. 1  is a vertical cross-sectional view of a container embodying the principles of the invention showing a fluid supply container and a near-empty fluid waste container; 
         FIG. 2  is a vertical cross-sectional view of a container similar to  FIG. 1  showing a partially-full fluid supply container and a partially-full fluid waste container; 
         FIG. 3  is a vertical cross-sectional view of a container similar to  FIG. 1  showing a near-empty fluid supply container and a full fluid waste container; and, 
         FIG. 4  is a front elevational view of the container in  FIG. 1  showing a scaled view port and visual indicia. 
     
    
    
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the present invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. To illustrate the function of the invention, its application within an HPLC system is described, but it should be fully understood that the present invention is not limited to HPLC use only. 
     Referring to the drawings in greater detail, and more particularly to  FIG. 1 , a transportable container, generally designated  10 , is seen to include an outer container  12  and a pair of inner containers  14  and  15 , respectively. The outer container  12  functions as a holder, while the inner containers  14  and  15  function as variable-volume, fluid-holding cells. Herein, the inner containers  14  and  15  are flexible sealed bags that divide the outer container  12  into separate, isolated compartments. As shown herein, the bags  14  and  15  are generally positioned one on top of the other. 
     The outer container  12  is defined by a bottom wall  17 , a top wall  18  spaced above the bottom wall  17  and a wrapping side wall  19  extending therebetween. The top edge of the side wall  19  connects to the top wall  18  and the bottom edge of the side wall  19  connects with the bottom wall  17  to define an internal space  20  with a predetermined volume. The outer container  12  is preferably made from rigid material, such as cardboard, plastic or other suitable material. The outer container  12  may also be made of somewhat flexible material so long as it is capable of carrying the inner containers and functions suitably for the purposes proposed herein. When used with HPLC systems, the internal volume is defined to be sufficient for one day of operation of typical HPLC analysis. With a most common flow rate in HPLC 1 milliliter per minute, the overall volume of fluid should be about 1 liter which enough for 16 hours of operation. 
     The inner containers  14  and  15  are disposed within the volume of the outer container  12 , are deformable, and are impermeable to the fluids that they are to hold. The first inner container  14  is collapsible and defines an internal chamber  22  having a variable volume. The second inner container is expandable and defines an internal chamber  23  having a variable volume. 
     Each of the inner containers  14  and  15  when fully expanded is capable of substantially occupying the entire internal volume of the outer container  12  not occupied by the other inner container. While the inner containers  14  and  15  may take many forms, they are shown herein as plastic bags folded in accordion fashion. They may also be flaccid, crushable bags or take on any other suitable form. The bags are preferably made with non-opaque material, i.e., clear or translucent, so that the fluids and their respective volumes within the containers  14  and  15  may be viewed by the user. The inner containers  14  and  15  may be sealed within the outer container  12 , or removable from the outer container  12 , or otherwise carried by the outer container  12 . 
     The first inner container  14  has an outlet port, generally designated  30 , communicating with the internal chamber that is adapted to receive a flow line (not shown) to withdraw fluid from the chamber. The second inner container has an inlet port, generally designated  31 , communicating with the internal chamber that is adapted to receive a flow line (not shown) to deliver fluid to the chamber. 
     The ports  30  and  31  respectively include straw-like, elongate, hollow tubes  33  and  34  that have upper free ends exposed above the top of the outer container  12 . The tubes  33  and  34  extend downwardly terminating internally at lower ends near the bottom of the chambers  22  and  23  of the inner containers  14  and  15 . The exposed ends of the tubes  33  and  34  include releasable, low-pressure connectors, such as luer-type connectors  36  and  37 , respectively, enabling a user to selectively connect flow lines thereto. The connectors are appropriately configured as different types, such as female connector  36  and male connector  37 , so there is only one way to properly connect the containers to a HPLC system. The supply tube  33  may be rigid or flexible and include perforations or openings, collectively designated  38 , in its side wall along the length thereof to prevent the tube  33  from being plugged while fluid is suctioned from the inner supply container  14  through its internal passageway. The discharge tube  35  is preferably rigid so that the tube opening at the lower end of its internal passageway will remain near the bottom of the inner waste container  15 . 
     The outer and inner containers are configured so that the volume of the outer container  12  will be substantially equal to the overall fluid volume held by the inner containers  14  and  15 . As seen in the drawings, when fluid is withdrawn from filled container  14 , it gradually deflates ( FIG. 2 ) to a collapsed condition ( FIG. 3 ) enabling the empty container  15  to inflate. Similarly, as a similar amount of fluid is delivered to the empty container  15 , it gradually inflates ( FIG. 2 ) to an expanded condition ( FIG. 3 ) filling the space no longer occupied by container  14 . In a HPLC system, fluid going into the system is substantially the same as the waste fluid exiting the system. Thus, mobile phase can be delivered from and withdrawn using a single transportable outer container. 
     It is also contemplated that if more than one solvent is required for a specific analysis, the outer container may have two or more inner containers filled with different unused mobile phase and one or more additional empty inner containers for receiving and isolating different types of waste. 
     To allow the inner containers  14  and  15  to be seen, a view port  40  is formed in the side wall  19  of the outer container  12 . This may be a cutout as shown in  FIG. 4  or it may be a portion of the side wall that is formed with clear material. In this manner, a user is permitted to visually determine the fluid volume in each of the containers. 
     A colorant or dye may be added to the waste container  15  so that as fluid is introduced therein, the visibility of the fluid in increased and may be perceived more easily by a user. 
     It should be understood that disposal of chemical waste is a continuing problem. In addition, the disposal of liquid waste is more complex and needs to be carried out differently than the disposal of solids. To lessen liquid disposal issues of the waste receiving container  15 , a small amount of superabsorbent can be placed in the waste container  15 . A superabsorbent is capable of holding many times more liquid then its own weight. The superabsorbent transforms waste fluid into a solid, semi-solid or gel form. After mobile phase is consumed and directed into the inner container  15 , the waste is solidified by the superabsorbent and the container  12  can thereafter be disposed as solid waste. 
     Superabsorbents used with alcohols are discussed in an article entitled “Super Alcohol-Absorbent Gels of Sulfonic Acid-Contained Poly(acrylic acid)” by Kourosh Kabiri, et al., published in the Journal of Polymer Research, Volume 19, Number 3, pp. 449-58 (2010). One commercial superabsorbent that may be used to produce hydroalcoholic gels in an HPLC application is a commercial product known as Carbopol® made by Lubrizol of Wickliffe, Ohio. 
     As best seen in  FIG. 4 , indicia  42  or information printed or otherwise is placed on the side wall  19  of the outer container  12 . This user viewable indicia  42  denotes identifying parameters relating to the container including the name of the fluid, its composition, its manufacturer, lot number, expiration date, disposal instructions, the name of the user, etc. Scannable bar codes can be preprinted on the external surface of the outer container enabling automated scanning of information. When placed adjacent to the view port  40 , a scale  43  or measure markings indicating the volume or ratio of new fluid and used fluid can be easily ascertained by a user. 
     While the container  10  described herein is intended to deliver fresh mobile phase and remove used-up (waste) mobile phase in the HPLC field, this container design can also be used in other fields of chemical analysis where liquid is used as a transport means. One such example would be use in flow injection analysis (FIA) described above. 
     When the container  12  is delivered to a customer or user, the container  12  will be filled with premixed mobile phase which substantially occupies the entire container&#39;s volume as seen in  FIG. 1 . When this container attached to HPLC instrument, the mobile phase is suctioned from the bag  14  by the HPLC instrument pump. The used up mobile phase (waste) after analysis is returned to the same container  12  into the empty bag  15  as seen in  FIG. 2 . In this manner, the outer container  12  holds both fresh mobile phase and waste mobile phase. When the mobile phase is completely consumed, substantially the entire volume of the outer container  12  is taken up by the waste fluid as seen in  FIG. 3 . At this point, the container  12  can be disconnected from the instrument and disposed of or sent for recycling. 
     It is understood that the containers may comprise any hollow container, including but not limited to bags, jars, bottles, boxes, or the like, as long as they are expandable, i.e., they may be inflated or deflated to change their internal volume. For example, an inner bag may be suitable if it is thin-walled, flaccid, or crushable; a bottle may be suitable if made of plastic with an accordion-style side wall; or, a box may be suitable it is foldable or collapsible. It is also understood that where low pressures are involved, the container material and construction should be selected such that the inner containers yield to pressure readily and without resistance so that they are easily inflated and deflated. It also understood that the inner containers have variable volumes and that the collapsible container may be expandable and that the expandable container may be collapsible. 
     INDUSTRIAL APPLICABILITY 
     It should be apparent the container described herein is a simple, functional unit that is effective and easily manufactured. 
     Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure, and the appended claims. 
     It should be understood that the terms “top,” “bottom,” “upper,” “lower,” “front,” “back,” “side,” “end,” “first,” “second,” and similar terms as used herein, have reference only to the structure shown in the drawings and are utilized only to facilitate describing the invention. The terms and expressions employed herein have been used as terms of description and not of limitation. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It will also be observed that the various elements of the invention may be in any number of combinations, and that all of the combinations are not enumerated here. It will be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. While specific embodiments of the invention have been disclosed, one of ordinary skill in the art will recognize that one can modify the materials, dimensions and particulars of the embodiments without straying from the inventive concept.