Patent Application
20140284284
Not Applicable
Not Applicable
Not Applicable
Not Applicable
This invention relates in general to a method and apparatus for extracting organic chemicals from water directly within sample collection vessels, More specifically, the invention relates to an apparatus and procedure designed to effect the removal of an immiscible solvent from an inverted bottle following an in-situ liquid-liquid extraction process.
Water is routinely sampled and tested for chemical contaminants for human health and a number of other reasons. Most chemical analysis methods require removal of organic chemicals from water by partitioning into an immiscible solvent, often heavier than water, by a process known as liquid-liquid extraction. If the chemicals to be extracted have a greater affinity for the solvent than the water, and, if there is sufficient interaction between the extracting solvent and the water, the contaminating chemicals transport from the water to the solvent and the process will be effective. There are two techniques commonly in use today.
The most common features use of a separatory funnel, generally a pear shaped vessel fashioned with a cap on one end and a narrow opening with a stop-cock on the other. A water sample and an extracting solvent are added together and vigorously shaken either manually or mechanically for a period of time to maximize interaction between the water and solvent. Subsequently, the separatory funnel is stood upright and the liquid layers are allowed to settle and separate until a clear demarcation between the liquid layers may be observed. Removing the cap for ventilation and by manipulating the stopcock, the lower layer is manually drained off into another container by observing the movement of the visible interface (meniscus) between the two fluids. The housing of the separatory funnel, or at least a portion of it, must necessarily be clear or at least translucent to facilitate viewing a moving interface. The procedure is often repeated with fresh solvent to maximize the recovery of the extraction process. Thus, a separatory funnel has a dual purpose, to provide a mixing chamber for water and an extracting solvent as well to serve as a vehicle for separating the two liquids following the extraction. An example of a separatory funnel may be found in U.S. Pat. No. 1,049,411 issued to Roscoe H. Shaw on Jan. 7, 1913.
U.S. Pat. No. 5,478,478 issued to Sandra Griswold on Dec. 26, 1995 introduced a modification to facilitate the separation of two fluids within a separatory funnel by preventing vortexing. U.S. Pat. No. 5,580,528 issued to James P. Demers on Dec. 3, 1996 introduces an unbreakable plastic stem to a glass separatory funnel improving the safety and durability of the device.
Another technique commonly used to extract water samples, continuous liquid-liquid extraction, makes use of an elaborate glass apparatus to automate the process. A heavier than water, substantially immiscible solvent (typically methylene chloride) is boiled and vaporized up into a cold water jacket. Re-liquidified solvent drops into a vessel containing the water sample and the solvent is recycled. The initial process generally takes 18 to 24 hours and is most often followed by a second extraction of 18 to 24 hours after altering the pH of the water sample. U.S. Pat. No. 5,156,812 is an example of this apparatus.
With a fairly new technique, organic compounds may also be removed from water by passing the water through a solid sorbent material from which the pollutants may subsequently be dislodged with solvent or a mixture of solvents.
With these procedures the separated solvent, now containing the chemicals that had originally been in the water, is usually reduced in volume (concentrated) by evaporation to enable the extracted organic compounds to be detected at extra low levels. All of these processes are labor intensive, costly, time-consuming and subject to contamination from a number of sources.
This invention was born of a need to remove extracting solvent from a bottle, an obstacle posed by the development a new, greatly simplified method for extracting chemicals from water. With this new technique, solvent (or a mixture of solvents) is added directly to the water in original sample vessels to enable the extraction to take place directly within the bottles used to collect, transport and store the water samples (an in-situ extraction). Once the solvent(s) is introduced, the bottles are spun horizontally for a number of hours at 3 rpm. This subtle movement provides the necessary interaction between the water and solvent to obtain an extraction result equaling or exceeding the efficiency of those processes in use today as described above. This new method for extracting chemical from water, of which this patent device is an essential element, has important advantages. Among these are significant solvent usage reduction (a green technology), labor abatement, improved precision, contamination minimization, enhanced safety, and greatly reduced cost.
The initial research conducted to explore and refine the new extraction method was necessarily, counterproductively, administered using a piece of equipment the technique was, in part, designed to replace. A separatory funnel (as mentioned above) was the only tool available to effect the removal of the extracting fluid from the bottles following the in-situ process. A clear and obvious need to find a simpler means to dispense the extracting solvent from an inverted bottle led to the discovery and refinement of the subject device (given the name “funnel-cock”).
The device is a modification of a funnel. There is prior art regarding the improvement of funnels. In 1866, two patents were issued, one to Arthur Wilson (No. 53,074) to allow a funnel to be attached to a faucet to control flow. The second patent was issued to A. H. Whitney (No 55,941) entailing an improvement to a funnel to allow liquids to be measured and dispensed in a simplified manner. U.S. Pat. No. 105,857, issued to Franklyn Smith Jul. 26, 1870, describes an improvement to a measuring funnel to enable flammable liquids to be dispensed safely by eliminating exposure to air.
The invention prototype is a funnel adaptation created to enable immiscible solvent to be dispensed from an inverted bottle in a controlled, efficient manner. The device need be fabricated of a clear or translucent material, etched with grooves or forged with ridges on the inner surface and fitted with a stopcock. The large opening of the funnel is sized specifically to comfortably seat and mate with the lip of inverted bottles of varying sizes and shapes, particularly those commonly used for water sampling. The dimensions are further refined to create a gap to retain the inevitable but limited spillage that occurs when a bottle full of liquid(s), is inverted onto the device. The grooves or ridges are strategically placed to prevent a seal from forming between the inverted bottle lid and the inner funnel surface. Consequently, when the funnel is used to discharge a heavier than water solvent from an inverted bottle, the grooves or ridges allow air to enter the bottle while the fluid is being dispensed thereby striking a balance between a vacuum formed within the bottle headspace and atmospheric pressure. The clear or translucent construction material allows the fluid discharge to be viewed while the flow is controlled with a stopcock.
More specifically, the invention entails a funnel of specific conical size and shape made of clear or translucent material, or containing at least a section of clear or translucent material, with a larger circular open top end and a smaller tubular lower end. The smaller tubular end may house or be fashioned to house a stopcock or other flow controlling mechanism. The inner surface of the upper part of the funnel is etched with one or more grooves or is fabricated with one or more ridges. As the bottle full of liquid and funnel are clasped and inverted together, the purposeful extension of the funnel beyond the lid of the bottle is made to create a void sufficient to retain overflow limited and controlled by the natural competing forces of vacuum and pressure. Moreover, the sizing allows for a snug fit (but not seal) about the neck of the bottle while the funnel wall is extended up over the neck up to but not quite reaching the base of the bottle, typically 1 liter in size. Thus an overflow containment space is formed within the flat funnel wall, the cylindrical bottle neck and the lip of the bottle. The groove(s) or ridges(s) within the funnel prevent a seal about the lid of the bottle and allow venting to occur in a controlled fashion as the stopcock is opened and the fluid is discharged.
It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purpose of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the claim of the invention.
For a more complete understanding of this invention and the advantages thereof, reference is made to the following descriptions taken in conjunction with the accompanying drawings in which:
Embodiments of the funnel cock are given in the accompanying drawings.
As shown in
