Patent Description:
Solid phase extraction is a method in which a target material is adsorbed using a filler having a specific property, such as beads, and purified and concentrated using a solvent to perform a pretreatment. In this case, a device for packing the filler is required. A micro device having a small size is used in order to increase a recovery rate and shorten a pretreatment time. In addition, a micro device is used to detect trace amounts of materials. The use of a micro device has advantages of being environmentally friendly since it can reduce solvent consumption.

The shape of the conventional micro device for solid phase extraction <NUM> is as shown in <FIG>. There is provided a dam <NUM> inside the micro device <NUM> so that beads <NUM> could not pass through but only the fluid flows. At this time, as the flow path is reduced due to packing of beads in the rear portion of the dam, differential pressure is generated. The smaller the porosity, the greater the differential pressure. In the conventional micro device of <FIG>, a dam is installed on the left side, the right side, and the center of the device. Accordingly, a larger amount of fluid flows in the left and right directions, in which filling distance of the beads is relatively short. As a result, there is generated a non-uniform flow distribution of the fluid.

<CIT> discloses a filter comprising an inlet, an outlet, a dam-forming portion which encloses a dam called an affinity filter which is configured to allow solvent to flow therethrough, but configured to prevent any filler from passing therethrough. Solvent may flow through the affinity filter and may then pass through an aperture to be then discharged through the outlet. The document is silent that the dam is configured to allow discharge of the solvent via the side surface of the dam.

<CIT> discloses a solid phase extraction system comprising a circular inlet and a circular outlet, a housing in which is disposed a filter having a circular cross-section. The filter is placed closer to the outlet than to the inlet.

In order to solve the non-uniform flow distribution of the fluid in the conventional micro device for solid phase extraction, there is a need for a new type of micro device for solid phase extraction capable of realizing uniform extraction by flowing a fluid at a uniform flow rate.

The micro device for solid phase extraction according to the present invention comprises:.

In addition, in the micro device for solid phase extraction according to the present invention, each of the inlet, the outlet, the dam-forming portion, and the dam has a circular cross section with respect to the central axis in a direction in which the inlet extends, the cross section being perpendicular to the central axis, and each of a diameter of the inlet and a diameter of the outlet may be smaller than a diameter of the dam-forming portion.

In addition, the micro device for solid phase extraction has a first end portion connected to the inlet and a second end portion connected to the outlet which are both ends of the dam-forming portion, wherein the dam may be located closer to the second end portion than the first end portion, and the dam may be located by a predetermined distance away from the second end portion.

In addition, in the micro device for solid phase extraction, each of the shape of the second end portion and the shape of the surface facing the second end portion of the dam may have a shape protruding toward the outlet.

In addition, in the micro device for solid phase extraction, the shape of the second end portion and the shape of the surface facing the second end portion of the dam may be a conical shape.

In addition, in the micro device for solid phase extraction, the filler may be beads.

In addition, in the micro device for solid phase extraction, the total diameter of the micro device may be <NUM> to <NUM> and the total length of the micro device may be <NUM>.

In addition, in the micro device for solid phase extraction, the diameter of the filler is from <NUM> to <NUM>,.

According to the micro device for solid phase extraction of the present invention, it is advantageous that a uniform fluid flow is formed along the central axis of the micro device for solid phase extraction, thereby realizing uniform solid phase extraction.

In addition, in the micro device for solid phase extraction according to the present invention, each of the inlet, the outlet, the dam-forming portion, and the dam has a circular cross section with respect to the central axis in a direction in which the inlet extends, the cross section being perpendicular to the central axis, and each of a diameter of the inlet and a diameter of the outlet may be smaller than a diameter of the dam-forming portion.

Hereinafter, the micro device for solid phase extraction according to the present invention will be described in detail. The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and are not intended to limit the technical scope of the present invention.

In addition, the same or corresponding components will be denoted by the same reference numerals regardless of symbols, and redundant description thereof will be omitted. For convenience of explanation, the size and shape of each component shown may be exaggerated or reduced.

<FIG> and <FIG> show a front view of a micro device for solid phase extraction <NUM> according to an embodiment of the present invention. The micro device for solid phase extraction <NUM> includes an inlet <NUM>, a dam-forming portion <NUM>, and an outlet <NUM>. A filler <NUM> (e.g., beads) and a solvent are injected through the inlet <NUM> and the injected filler <NUM> and solvent move into the dam-forming portion <NUM> connected to the inlet <NUM>. The filler <NUM> is filled in the rear of the dam <NUM> in the dam-forming portion <NUM>, and the solvent is discharged through the outlet <NUM> connected to the dam-forming portion <NUM> via the side surface of the dam <NUM>.

The dam-forming portion <NUM> of the micro device for solid phase extraction <NUM> according to the present invention has a shape of cylinder having a circular cross section (or disk having a predetermined length). The dam-forming portion <NUM> includes a dam <NUM> on the side of outlet <NUM>. The dam <NUM> also has a shape of disk having a circular cross section. With respect to both ends of the dam-forming portion having a cylindrical shape, an end of the dam-forming portion <NUM> connected to the inlet <NUM> is referred to as a first end portion <NUM> and an end of the dam-forming portion <NUM> is connected to the outlet <NUM> is referred to as a second end portion <NUM>. The dam <NUM> is located close to the second end portion <NUM> of the dam-forming portion <NUM> and the dam <NUM> is located by a predetermined distance away from the second end portion <NUM> so that the solvent can flow toward the outlet <NUM>. However, the present invention is not limited to the above. For example, the dam <NUM> may be manufactured by a perforated plate having holes with a size smaller than that of the filler <NUM>, or a mesh structure such that the filler <NUM> could not pass therethrough. In this case, the solvent may flow to the outlet <NUM> through the dam <NUM> as well as the side surface of the dam <NUM>.

The second end portion <NUM> protrudes toward the outlet <NUM>, and for example, may have a conical shape as shown in <FIG>, in order to minimize resistance due to the second end portion <NUM> when the solvent which passed by the dam <NUM> moves toward the outlet <NUM> in the dam-forming portion <NUM>. The dam <NUM> may be in the form of disk as described above, but the front portion of the dam <NUM> may also have a conical shape, like the second end portion <NUM> having a conical shape, as shown in <FIG>.

In addition, as shown in <FIG>, in case that the diameter of the dam-forming portion <NUM> is equal to the diameter of the dam <NUM>, there is further provided a protruded portion <NUM> in which a side surface surrounding the portion where the dam <NUM> is located in the dam-forming portion <NUM> is further protruded so that the protruded portion <NUM> allows the solvent to move between the side surface of the dam <NUM> and the inner surface of the dam-forming portion <NUM>. In this case, the diameter of the second end portion <NUM> of the dam-forming portion <NUM> may be larger than the diameter of the first end portion <NUM> of the dam-forming portion <NUM>. As shown by a flow line of the solvent in <FIG>, the solvent may pass between the fillers <NUM>, pass by the protruded portion <NUM> of the dam-forming portion <NUM> and pass by a space between the second end portion <NUM> of the dam-forming portion <NUM> and the dam <NUM>, and then move toward the outlet <NUM>.

A solvent inlet <NUM>, which is the inlet of the space through which the solvent flows between the side surface of the dam <NUM> and the inner surface of the dam-forming portion <NUM>, has a width smaller than the diameter of the filler <NUM>.

<FIG> shows a front view of a micro device for solid phase extraction <NUM>' according to other embodiment of the present invention, in which the micro device for solid phase extraction of <FIG> is partially modified. As shown in <FIG>, in case that the diameter of the dam <NUM>' is smaller than the diameter of the dam-forming portion <NUM>', the solvent can pass by the side surface of the dam <NUM>', and therefore the dam-forming portion may not need a protruded portion. In this case, a solvent inlet <NUM>', which is the inlet of the space through which the solvent flows between the side surface of the dam <NUM>' and the inner surface of the dam-forming portion <NUM>', has a width smaller than the diameter of the filler <NUM>.

Referring to <FIG> again, as described above, the inlet <NUM> and the outlet <NUM> may be connected to the dam-forming portion <NUM> and formed integrally with the dam-forming portion <NUM>. Each of the inlet <NUM> and the outlet <NUM> may have a long cylindrical shape, for example. In addition, each of the inlet <NUM> and the outlet <NUM> may be located on the same line with respect to the center axis in a longitudinal direction of the dam-forming portion <NUM>. The diameter of each of the inlet <NUM> and the outlet <NUM> is smaller than the diameter of the dam-forming portion <NUM>.

A size of the micro device for solid phase extraction <NUM>, for example, as shown in <FIG>, a diameter of the micro device for solid phase extraction <NUM> (i.e., a diameter of the micro device <NUM> including the protruded portion <NUM> of the dam-forming portion <NUM>) may be <NUM> to <NUM>, and a total length of the micro device for solid phase extraction <NUM> (i.e., a total length of the micro device including the inlet <NUM>, the dam-forming portion <NUM> and the outlet <NUM>) may be about <NUM> to <NUM>, and in one embodiment may be about <NUM>. A diameter of the filler <NUM> may be <NUM> to <NUM>. A diameter of the inlet <NUM> may be <NUM> to <NUM>, and a length of the inlet <NUM> may be about <NUM>. A diameter of the outlet <NUM> may be <NUM> to <NUM>, and a length of the outlet <NUM> may be about <NUM>. A length from the first end portion <NUM> of the dam-forming portion <NUM> to the rear portion of the dam <NUM> (i.e., a length of the region in which the filler <NUM> can be filled) may be <NUM> to <NUM>. A length from the rear portion of the dam <NUM> to the second end portion <NUM> may be <NUM> to <NUM>. A length of the dam <NUM> may be <NUM> to <NUM>. A width of the solvent inlet <NUM> of the protruded portion <NUM> may be <NUM> to <NUM> to prevent the filler <NUM> from passing through. The dimensions shown in <FIG> are merely examples, and the present invention is not limited thereto, and various modifications and changes may be made according to the various environments in which the present invention is implemented.

The filler <NUM> in the dam-forming portion <NUM> is blocked by the dam <NUM> and could not exit toward the outlet <NUM>, and therefore the filler <NUM> may be filled in the rear of the dam <NUM>. As shown in <FIG>, the filler <NUM> may be filled in the form of disk in the rear of the dam <NUM>, depending on the flow of the solvent. The filling shape of the filler <NUM> is shown in <FIG> as 200a.

According to the present invention, since the same filling distance of the filler <NUM> from the central axis in the longitudinal direction of the dam-forming portion <NUM> generates a similar differential pressure, a uniform flow distribution of the solvent in the micro device for solid phase extraction <NUM> can be achieved. Therefore, the dam-forming portion <NUM> and the dam <NUM> are designed to be radially symmetric (cylindrical) from the central axis so that the fillers <NUM> are filled at the same distance. Accordingly, the shape of the region 200a filled with the filler <NUM> becomes a disk shape as shown in <FIG>, and the inlet <NUM> and the outlet <NUM> are located on the central axis. That is, each of the dam-forming portion <NUM> and the dam <NUM> has a circular cross section perpendicular to the central axis in the direction in which the inlet <NUM> extends. In the dam-forming portion <NUM>, the filler <NUM> is filled in the form of disk with respect to the central axis. As such, when the cross section has a circular shape, the filler <NUM> is formed in the fluid flow direction with the same distribution from the central axis of the micro device for solid phase extraction <NUM>, thereby eliminating unnecessary volume of the micro device for solid phase extraction <NUM> and maximizing the efficiency of solid phase extraction.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the above detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claim 1:
A micro device (<NUM>, <NUM>') for solid phase extraction comprising:
an inlet (<NUM>) configured to receive injection of a solvent and a filler (<NUM>);
an outlet (<NUM>) configured to receive discharging of the solvent; and
a dam-forming portion (<NUM>, <NUM>' ) located between the inlet (<NUM>) and the outlet (<NUM>); and
a dam (<NUM>, <NUM>') disposed within the dam-forming portion (<NUM>, <NUM>'), the dam (<NUM>, <NUM>') configured to allow the solvent to flow therethrough and configured to allow the solvent to be discharged via a side surface of the dam (<NUM>, <NUM>') surrounding the portion where the dam (<NUM>) is located in the dam-forming portion (<NUM>), but configured to prevent the filler (<NUM>) from passing therethrough,
wherein in case that the diameter of the dam-forming portion (<NUM>) is equal to the diameter of the dam (<NUM>), there is further provided a protruded portion (<NUM>) in which the side surface is further protruded so that the protruded portion (<NUM>) is configured to allow the solvent to move between the side surface of the dam (<NUM>) and the inner surface of the dam-forming portion (<NUM>), or
in case that the diameter of the dam (<NUM>') is smaller than the diameter of the dam-forming portion (<NUM>'), the solvent can pass by the side surface of the dam (<NUM>'),
wherein each of the dam-forming portion (<NUM>, <NUM>') and the dam (<NUM>, <NUM>') has a circular cross section with respect to a central axis of the micro device, the central axis extending in a longitudinal direction of the inlet (<NUM>) in which the inlet (<NUM>) extends, each cross section being perpendicular to the central axis, and wherein the dam-forming portion (<NUM>, <NUM>') is configured to accommodate the filler (<NUM>) deposited onto the dam (<NUM>, <NUM>') in the form of a disk that is centered with respect to the central axis in the dam-forming portion (<NUM>).