JP6693028B2 - Filters for chromatography columns - Google Patents

Description

  The present invention relates to filters for fluids, and more particularly to filters for columns.

  BACKGROUND ART Chromatography has been widely used in academia and industry in the world as a technique for separating and purifying substances. Chromatography was invented in 1906 by the Russian botanist Mikhail Semyonovich Tvette (Михаил Семёнович Цвет), in the process of passing a substance called the mobile phase on the surface or inside of the substance called the stationary phase (carrier). It is characterized in that the substances are separated.

  There are three types of mobile phases in chromatography, gas, liquid and supercritical fluid. Chromatography is called gas chromatography, liquid chromatography or supercritical fluid chromatography depending on the type of mobile phase. Generally, in chromatography, a dedicated elongated tube called a column for holding a carrier is used.

In a column for chromatography, a filter is often used to keep the carrier in the column from leaking and to remove foreign substances and impurities contained in the mobile phase that are not analyzed. For example, when silica (SiO ₂ ) is used as a carrier for liquid chromatography, a filter is placed before and after the silica particles are packed to keep the silica particles in the column so as not to leak outside. Foreign substances and impurities in the mobile phase are being removed.

  Generally, a column for chromatography is washed in preparation for the next use after the completion of the chromatography, and the above-mentioned filter is also washed at that time. At this time, the foreign matter clogged in the filter may not be removed even by washing, and the filter may be clogged. If the filter becomes clogged, foreign substances and impurities cannot be removed during the next chromatography, which may interfere with experiments and analysis.

  In particular, a sintered metal filter manufactured from atypical powders often causes clogging, and it is often the case that foreign matter cannot be removed even by washing by flowing a fluid in a direction opposite to that in use. The term "sintered metal" as used herein refers to a metal material produced from solid metal powder by using the phenomenon that when a solid powder aggregate is heated at a temperature lower than its melting point, it solidifies into a dense body called a sintered body. is there. If the clogging of the filter cannot be eliminated even after repeated washing, there is no choice but to discard the filter and use a new one, leading to an increase in the cost and labor required for performing chromatography.

  The problem to be solved by the present invention is to alleviate the problem of filter clogging used in conventional chromatography columns. Another object of the present invention is to provide a column filter having sufficient strength while reducing the problem of filter clogging.

  The filter according to the present invention is composed of a plurality of sintered non-magnetic metal spheres, which solves the above problems.

  Another filter according to the invention consists of a plurality of sintered glass spheres, which solves the above problem.

  Another filter according to the invention consists of a plurality of sintered ceramic balls, which solves the above-mentioned problems.

  Another filter according to the present invention is composed of a plurality of sintered synthetic resin spheres, which solves the above problems.

  The filters may have a substantially columnar shape, and two filters may be used as a set for placement in a chromatography column.

  The filter may have a diameter of 2 to 10 mm, a thickness of 1 to 3 mm, and a filtration accuracy of 0.5 to 100 μm.

  According to the filter of the present invention, foreign matters and impurities can be easily removed from fluids such as air, water and oil. In particular, by mounting it on a chromatography column, it is possible to remove foreign substances and impurities from the fluid when performing chromatography.

  Since the filter of the present invention is easier to clean than the conventional sintered metal filter, the device can be easily maintained in a hygienic and safe state. In addition, since the filter cannot be washed and needs to be replaced for a longer period of time than a conventional sintered metal filter, it is possible to reduce the labor and cost required for filter replacement.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A to 1C are a plan view, a front view and a perspective view of a filter according to the present invention, respectively. The filter 10 according to the present invention is formed by sintering a large number of spheres, and has a substantially cylindrical outer shape as shown in the drawing. The size of the filter 10 is arbitrary, but it is desirable that the filter 10 has a diameter of 2 to 10 mm, a thickness of 1 to 3 mm, and a filtration accuracy of 0.5 to 100 μm for use in a chromatography column described later. The size of the sphere forming the filter 10 is appropriately selected according to the application, but the diameter is preferably several tens of μm to 200 μm.

  The spheres constituting the filter according to the present invention are, for example, non-magnetic metals such as austenitic stainless steel and copper, glasses such as silicate glass and soda lime glass, ceramics such as alumina and silicon carbide and silicon nitride, or polypropylene. It is made of various synthetic resins such as polyethylene terephthalate (PET) and fiber reinforced plastic (FRP) in which glass fibers and the like are added. If the spheres forming the filter according to the invention are made of synthetic resin, the synthetic resin is preferably a thermoplastic resin.

  The temperature at which the spheres constituting the filter according to the present invention are sintered depends on the melting point of the material. For example, in the case of austenitic stainless steel, the sintering temperature is around 1100-1400 ° C. Similarly, the sintering temperature of soda-lime glass is around 600 to 900 ° C, the sintering temperature of ceramics is around 1500 to 1800 ° C, and the sintering temperature of PET resin is around 200 to 500 ° C.

  The spheres that make up the filter according to the invention are preferably almost perfect spheres of the same size. Atypical powders are generally used in conventional sintered metal filters, and even when called spherical powders, metal powders that are non-uniform and cannot be called spherical because of technical limitations have been used. The filter according to the invention is quite different from conventional sintered metal filters in that the spheres that make up it are preferably all of the same size and are almost perfect spheres.

  2A and 2B are an exploded view and a completed view of a chromatography column equipped with a filter according to the present invention. The filters according to the present invention are usually installed as a set of two filters at both ends of the column so as to sandwich the carrier. This makes it possible to remove impurities before the fluid passes through the carrier and also remove impurities after passing through the carrier to improve the accuracy of chromatography.

  As shown in FIG. 2A, the column 20 includes a column pipe 21 and end fittings 22a and 22b. The column pipe 21 is a column body that is filled with a carrier, and the ends are connected to both ends of the column pipe 21 to hold the carrier in the column pipe 21. The end fittings 22a and 22b are components for fixing the column pipe 21 holding the carrier therein and connecting the column 20 to the pipes before and after it. Each component of the column 20 is usually made of metal such as stainless steel or synthetic resin.

  The filters 10a and 10b of the present invention are respectively arranged in the end fittings 22a and 22b so that the fluid passing through the column pipe 21 passes through the filters 10a and 10b before and after the passage. Preferably, the filters 10a, 10b have a diameter larger than the inner diameters of the ends of the column pipe 21, substantially equal to the outer diameters of the ends of the column pipe 21, and smaller than the inner diameters of the end fittings 22a, 22b. This is because, with the above dimensional relationship, the fluid passing through the column pipe 21 can be fixed in the end fittings 22a and 22b so as to pass through the filters 10a and 10b.

  Although the column 20 shown in FIGS. 2A and 2B is of a screw type, the end fittings in the column are fixed by a ferrule type in which a male screw, a ferrule and a female screw are used in addition to the screw type. The present invention can be practiced by using a ferrule type column.

  By assembling the components of the column 20 and the filters 10a and 10b of the present invention in the arrangement shown in FIG. 2A, the column 20 shown in FIG. 2B is completed. When performing chromatography, the fluid is flowed from the upper side to the lower side in FIG. 2B. The filters 10a and 10b of FIG. 2A are the same as the filters 10 shown in FIGS. 1A to 1C, and when placed in the column 20, impurities in the fluid passing through the column 20 can be removed.

  FIG. 3 is a block diagram of the entire chromatography apparatus in which the filter of the present invention is used. In the chromatography device 300, the solvent 301 is carried to the sample introduction part 303 by the pump 302, mixed with the sample in the sample introduction part 303, and then passed through the column 304. The column 304 is packed with a carrier as described above, but in the case of liquid chromatography, for example, it is packed with fine particles called a filler such as silica. The type of filler is properly selected depending on the purpose of analysis and the target component.

  The fluid that has passed through the column 304 enters the detector 305, and various analyzes are performed depending on the type of the detector 305. Examples of the detector 305 include various types such as an ultraviolet / visible detector, a photodiode array, a differential refractive index detector, a fluorescence detector, an electrochemical detector, and a mass spectrometer. The specific operation is known and will not be described here.

  The analysis result of the detector 305 is recorded on paper, memory, magnetic media, etc. in the recorder 306, and displayed on the monitor 307. The recorder 306 may be, for example, a dedicated recording device for recording on a paper tape or a commercially available personal computer with dedicated recording software installed. The monitor 307 may be a dedicated monitor using a cathode ray tube or the like, or a commercially available personal computer display.

  FIG. 4 is a schematic diagram for explaining a fluid flow in a column when the filter of the present invention is used. In the cylindrical column 304, the particulate carrier 304c is held between the filters 304a and 304b according to the present invention, and the fluid passes from top to bottom as indicated by the arrow in the figure. When the fluid passes through the column 304, impurities are removed according to the filtering accuracy of the filters 304a and 304b, and a specific substance is adsorbed or the like depending on the property of the carrier 304c. Since the filters 304a and 304b are also for holding the particulate carrier 304c in the column 304 so as not to leak outside, the filtering accuracy of the filters 304a and 304b is smaller than the diameter of the particulate carrier 304c.

  The specific appearance of the filters 304a and 304b is as shown in FIG. 1, and FIG. 4 does not show the actual cross section of the column. Further, in FIG. 4, some elements included in the column are omitted for simplification of the drawing. An example of the appearance of an actual column incorporating the filter of the present invention is shown in FIG. 2B.

  FIG. 5A is a graph comparing the air flow rate of the spherical powder filter of the present invention with the air flow rate of the conventional atypical powder filter. Experimentally, the spherical powder filter of the present invention has been found to have improved pressure loss and air flow rate as compared to conventional atypical powder filters. As shown in FIG. 5A, the spherical powder filter of the present invention has an air flow rate of about 1.5 to 5 times in the range of filtration accuracy of 2 to 100 μm in both cases of the air pressures of 0.3 Mpa and 0.5 Mpa. Have

  FIG. 5B is a graph comparing the pressure loss of the spherical powder filter of the present invention with the pressure loss of the conventional atypical powder filter. As shown in FIG. 5B, the spherical powder filter of the present invention reduces the pressure loss by about 20 to 60% in the range of filtration accuracy of 2 to 100 μm in both cases of the air pressures of 0.3 Mpa and 0.5 Mpa. There is. 5A and 5B show the results when the filter material is non-magnetic stainless steel.

  It can be applied to remove foreign substances and impurities contained in various fluids such as gas and liquid. In particular, it can be applied to a column for chromatography to remove foreign substances and impurities in the fluid.

3 is a plan view of a filter according to the present invention. FIG. 1 is a front view of a filter according to the present invention. 3 is a perspective view of a filter according to the present invention. FIG. 1 is an exploded view of a chromatography column equipped with a filter according to the present invention. 1 is a completed view of a chromatography column equipped with a filter according to the present invention. It is a block diagram of the whole chromatography device in which the filter of the present invention is used. It is a schematic diagram for explaining the flow of the fluid in the column when using the filter of the present invention. It is a graph which compared the air flow rate of the spherical powder filter of this invention, and the air flow rate of the conventional atypical powder filter. It is a graph which compared the pressure loss of the spherical powder filter of this invention, and the pressure loss of the conventional atypical powder filter.

10, 10a, 10b, 304a, 304b Filter 20, 304 Column 21 Column pipe 22a, 22b End fitting 301 Solvent 302 Pump 303 Sample introduction part 304c Carrier 305 Detector 306 Recorder 307 Monitor

Claims (6)

A filter which is composed of a plurality of sintered non-magnetic spheres and has a filtration accuracy of 0.5 to 100 μm and which can pass a fluid (when the sphere is made of metal, the material is stainless steel or copper. As long as the sphere is non-metallic, the material is glass or synthetic resin ).   The filter according to claim 1, wherein the sphere is a sphere made of stainless steel or copper.   The filter according to claim 1, wherein the sphere is a glass sphere.   The filter according to claim 1, wherein the sphere is a synthetic resin sphere. The filter according to any one of claims 1 to 4 , which has a substantially columnar shape and is used as a set of two for placement in a chromatography column. The filter according to claim 5 , which has a diameter of 2 to 10 mm and a thickness of 1 to 3 mm.