JP2008267969A - Particle diameter measuring method and particle diameter measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately and easily measure a particle diameter in a short time. <P>SOLUTION: A particle diameter measuring method includes: the mixing step for mixing reference particles 21, 22, 23 having known particle diameters with a sample liquid containing a to-be-measured particle; the classifying step for introducing a mixture liquid created by the mixing step into a gap continuously varied so as to generate a capillary phenomenon, and classifying the to-be-measured particle and the reference particles 21, 22, 23 in accordance with the particle diameters; and the measuring step for measuring the particle diameter of the to-be-measured particle from a classification result of the to-be-measured particle and the reference particles 21, 22, 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a particle size measuring method for measuring the particle size of particles to be measured contained in a sample liquid and a particle size measuring apparatus therefor.

  The particle size measurement method for fine particles is a microscopic method in which the particle size is collected using a microscope such as an electron microscope after being collected on a filter or wafer, or the sample liquid is irradiated with inspection light to detect the scattered light. For example, there is a light scattering method for measuring the particle diameter.

  However, in the microscopy, there are problems that time and labor are required and there are individual differences in measurement results.

Further, in the light scattering method, as shown in Patent Document 1, it is necessary to perform calibration using a known reference particle before measuring a sample liquid. There is a problem that it takes. If the measurement cell is disposable (disposal), there is also a problem that calibration cannot be performed.
JP 2003-232716 A

  Accordingly, the present invention has been made to solve the above-mentioned problems all at once, and its main intended task is to measure the particle diameter easily and accurately in a short time.

  That is, in the particle size measuring method according to the present invention, a mixing step of mixing reference particles having a known particle size into a sample liquid containing particles to be measured, and a mixed liquid generated by the mixing step cause a capillary phenomenon and continuously. The step of classifying the measurement target particle and the reference particle according to the particle diameter by introducing the gap into the gap that changes with time, and the classification result of the measurement target particle and the reference particle, And a measuring step for measuring the particle diameter.

  Further, the particle size measurement method according to the present invention, a mixing step of mixing reference particles having a known particle size into a liquid sample containing particles to be measured, and a mixed liquid generated by the mixing step cause a capillary phenomenon, From the step of classifying the particles to be measured and the reference particles according to their particle sizes by introducing into the gap that changes stepwise, and the classification results of the particles to be measured and the reference particles, the particles to be measured And a measuring step for measuring the particle size.

  In such a case, the measurement target particles and the reference particles are classified at the same time in a plurality of different gaps simply by introducing the mixed liquid into the particle classification part by capillary action, so the measurement target particles are based on the reference particles. Can be measured and calibrated accurately and easily in a short time. In addition, by using the capillary phenomenon, a simple configuration that does not require external power can be achieved. Furthermore, since the particles to be measured are measured based on the reference particles, the particle size can be accurately measured even when the processing accuracy of the classification unit is low due to the fact that the classification unit is disposable. .

  In order to be able to measure a plurality of particles to be measured simultaneously with high accuracy, it is desirable to mix a plurality of types of reference particles having different particle sizes in the mixing step.

  In order to clarify the distinction between the measurement target particle and the reference particle, and to make each reference particle easy to see or measure, it is desirable that the reference particle is a colored particle.

  As a specific embodiment of the reference particles, polystyrene particles or the like to which the reference particles are attached a fluorescent dye can be used.

  In addition, a particle diameter measuring apparatus for realizing the particle diameter measuring method preferably includes a reference particle having a known particle diameter mixed in a sample liquid containing particles to be measured, a mixed liquid composed of the sample liquid and the reference particles. And a classification unit for classifying the measurement target particle and the reference particle, and the classification unit is provided in communication with the liquid introduction port, a liquid introduction port for introducing the mixed liquid, The mixed liquid is introduced into the inside by capillary action, and includes a particle classification unit that separates the measurement target particle and the reference particle according to the particle size, and the particle classification unit is formed from surfaces facing each other. In addition, the gap between the opposing surfaces changes continuously.

  In addition, the other particle size measurement apparatus is configured to introduce a reference particle having a known particle size mixed in a liquid containing the measurement target particle, and a mixed liquid including the sample liquid and the reference particle, and the measurement target particle and the reference particle A classification unit, and the classification unit is provided in communication with the liquid introduction port for introducing the mixed liquid and the liquid introduction port, and introduces the mixed liquid into the inside by capillary action. And a particle classifying unit that separates the measurement target particle and the reference particle according to the particle size thereof, wherein the particle classifying unit is formed from surfaces facing each other, and a gap between the facing surfaces is stepped. It is characterized by the fact that it changes.

  As a specific embodiment of the particle classification unit, the particle classification unit is configured by superimposing a flat plate-like first member and a flat plate-like second member with a spacer interposed at one end. Is desirable. In this case, the particle classification part can be configured very easily.

  Moreover, it is desirable that the particle classification part is configured by superimposing a flat plate-like first member and a second member having a step-like concave groove. This eliminates the need for spacers, reduces the number of parts, and facilitates assembly.

  According to the present invention configured as described above, the particle diameter can be measured accurately and easily in a short time.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a particle size measuring apparatus 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the classification unit 3.

<Device configuration>
A particle size measuring apparatus 1 according to the present embodiment measures the particle size of a measurement target particle contained in a sample liquid by using a capillary phenomenon. As shown in FIGS. And a classification unit 3.

  The reference particle 2 is a particle having a known particle diameter, and serves as a reference for measuring the particle diameter of the measurement target particle and a reference for measuring (calibrating) a gap of a particle classification unit 3B described later. In the particle size measuring apparatus 1 of the present embodiment, three types of reference particles 21, 22, and 23 are used. For example, the first reference particles 21 are a plurality of polystyrene particles with a diameter of 8 μm and a red fluorescent dye, and the second reference particles 22 are a plurality of polystyrene with a diameter of 4 μm and a yellow fluorescent dye. The third reference particle 23 is a plurality of polystyrene particles having a diameter of 2 μm and attached with a green fluorescent dye. In addition, the diameter of each of the reference particles 21, 22, and 23 is the same as or close to the particle size of the measurement target particle. And these reference particles 21, 22, and 23 are mixed in the sample liquid containing measurement object particle | grains so that it may mention later.

  The classification unit 3 is a disposable unit that classifies the measurement target particles and the reference particles 21, 22, and 23 simultaneously. Specifically, as shown in FIGS. 1 and 2, a liquid introduction port 3A for introducing a mixed liquid is provided in communication with the liquid introduction port 3A, and the mixed liquid is introduced into the inside by capillary action. And a particle classification unit 3B that classifies the measurement target particles and the reference particles 21, 22, and 23 according to their particle sizes.

  The particle classification part 3B is formed from the surfaces 31a and 32a facing each other, and the gap between the surfaces 31a and 32a facing each other changes continuously. Specifically, the particle classification unit 3B includes a flat plate-like first member 31 and a flat plate-like second member 32 with a spacer 33 interposed at one end, and the first member 31 and the second member 32 at the other end. It is a wedge-shaped space formed by overlapping so as to be in contact with each other. This space has a cross-sectional area that continuously decreases as the liquid advances by capillary action. Note that both ends of the overlapped first member 31 and second member 32 are mechanically held and fixed by the fixing member 4. Instead of using the fixing member 4, the first member 31, the second member 32, and the spacer 33 may be bonded and fixed to each other using an adhesive.

  Then, by overlapping the first member 31 and the second member 32, one of the openings formed on both side ends thereof is used as the liquid inlet 3A. In this way, since one of the openings formed at both ends is used as the liquid inlet 3A, it is not necessary to provide the holes constituting the inlet 3A in the first member 31 and the second member 32, and the classification unit 3 is manufactured. Can be easy.

  Both the first member 31 and the second member 32 are transparent rectangular flat plates made of acrylic resin, and at least inner surfaces 31a and 32a which are surfaces (opposing surfaces) forming the particle classification part 3B are flat surfaces.

  The inner surfaces 31a and 32a are coated to improve hydrophilicity. Specifically, the inner surfaces 31a and 32a are coated with a hydrophilic coating with a polysaccharide such as heparin, a nucleotide such as DNA, or a compound such as a surfactant. By applying the hydrophilic coating in this manner, the progress of the mixed liquid by capillary action can be promoted, and classification can be performed in a shorter time.

  The spacer 33 is made of an acrylic resin like the flat plate members 31 and 32, and has a thickness such that the particle classification portion 3B causes capillary action. In other words, the spacer 33 is interposed between the first member 31 and the second member 32, thereby determining the size of the wedge-shaped space and the maximum gap of the particle classification part 3B (maximum gap between the opposing surfaces). is there. For example, if the thickness of the spacer 33 is about 20 μm, the maximum gap of the particle classification portion 3B is about 20 μm. Of course, the minimum gap is 0 μm. Thus, by adjusting the thickness of the spacer 33, the classification accuracy (resolution) of the particle classification unit 3B can be adjusted.

<Particle size measurement method>
Next, a particle size measuring method using the particle size measuring device 1 of the present embodiment will be described.

  First, three kinds of reference particles 21, 22, and 23 are mixed into blood, which is a sample liquid containing particles to be measured, to generate a mixed liquid (mixing step).

  And as shown in FIG. 3, the opening (3 A of liquid inlets) of the classification unit 3 is made to contact a liquid mixture. Then, the mixed liquid is automatically sucked into the particle classification unit 3B from the liquid inlet 3A by capillary action and flows into the particle classification unit 3B. At this time, as shown in the plan view of FIG. 4, the surface 31a of the first member 31 and the second member 32 in which the measurement target particles and the reference particles 21, 22, and 23 included in the mixed liquid form the particle classification part 3B. , 32a is classified according to the particle size (classification step).

  From this classification result, the particles to be measured that are in the same row as the classified reference particles 21, 22, and 23 (classified into gaps of the same size) have the same diameter as the reference particles 21, 22, and 23. It turns out that there is, and the particle size of the particles to be measured can be measured. Further, the gaps where the reference particles 21, 22, 23 are present can be measured (measurement step).

  In the measurement step, the light source 6 for irradiating the inspection light from one side (the first member 31 side) of the classification unit 3 is provided, and the photodetector 7 is provided on the other (second member 32 side). As shown in FIGS. 1 and 5, the absorbance obtained by scanning the inspection light so as to cut through the classification unit 3 and detecting the transmitted light transmitted through the classification unit 3 at that time, and each location The particle size distribution of the particles to be measured can also be calculated based on the size of the gaps and the concentrations of the reference particles 21, 22, and 23. Specifically, the difference in absorbance in the region where each component in the measurement target particle is classified is calculated, the difference calculation result, the size of the gap at each location, and the reference particles 21, 22, Based on the concentration of 23, the particle size distribution of the particles to be measured is calculated. For example, in FIG. 5, the absorbance obtained in the region where platelets are classified (2 μm to 4 μm), the absorbance obtained in the region where platelets and red blood cells are classified (4 μm to 8 μm), and platelets, red blood cells and white blood cells are classified. The difference from the absorbance obtained in the region (8 μm ~) is calculated, and the particle size distribution is calculated using the difference calculation result. Note that the classification unit 3 may be set in an analyzer (not shown) including the light source 6 and the light detector 7 to measure the particle size distribution.

<Effect of this embodiment>
According to the in-liquid particle classification apparatus 1 according to the present embodiment configured as described above, the measurement target particles and the reference particles 21, 22, and 23 are simultaneously classified simply by introducing the mixed liquid into the particle classification unit 3 </ b> B by capillary action. Therefore, the particle diameter of the measurement target particle can be automatically measured and calibrated automatically in a short time with high accuracy based on the reference particles 21, 22, and 23. In addition, by using the capillary phenomenon, a simple configuration that does not require external power can be achieved.

  Further, since the particle size of the measurement target particle is measured with reference to the reference particles 21, 22, and 23, when the classification unit 3 is disposable and there is an error in the gap of the particle classification unit 3B (processing accuracy of the classification unit 3) Particle size can be measured with high accuracy. And since the processing precision of the classification unit 3 may be low, a running cost can be reduced.

  Furthermore, since the capillary phenomenon is used, the amount of sample liquid such as blood can be reduced. In addition, since the two flat plate members 31 and 32 are simply overlapped with the spacer 33 engaged with one end, the classification unit 3 can be manufactured very easily, and the size of the classification unit 3 can be reduced. Can be possible.

<Other modified embodiments>
The present invention is not limited to the above embodiment. In the following description, the same reference numerals are given to members corresponding to the above-described embodiment.

For example, in the classification unit 3 described above, the gap between the opposing surfaces 31a and 31b forming the particle classification part 3B is continuously changed. However, as shown in FIG. The gap between the opposing surfaces 31a and 31b may be changed stepwise while being formed from 31b. Specifically, the particle classification part 3B is a step-like space formed by superposing a flat plate-like first member 31 and a second member 32 having a step-like concave groove. This space has a cross-sectional shape that becomes smaller in steps. At this time, the lengths of the gaps (L _{1 to} L ₄ in the drawing) may be the same or different. In FIG. 6, the superimposed first member 31 and second member 32 are bonded and fixed with an adhesive.

  In the above embodiment, blood is classified, but it may be a liquid containing particles such as synthetic polymer, inorganic powder, metal powder, animal and plant cells, living cells, microorganisms, and emulsions.

  In the embodiment, the liquid (blood) that already contains the measurement target particles is used as the sample liquid, and the reference particles are mixed in the sample liquid. However, the measurement target particles and the reference particles are mixed in another solvent, A mixed solution may be generated.

  Furthermore, although the reference particles 21, 22, and 23 of the above embodiment use polystyrene particles to which a fluorescent dye is attached, they may be colored using other dyes or other than polystyrene particles. In addition, silica particles or the like may be used.

  In addition, in the above embodiment, the liquid inlet 3A is an opening formed on the side surface by the first member 31 and the second member 32. In addition, as shown in FIG. It is good also as the through-hole 3A provided in the 2 member 32. FIG. In addition, 3C in FIG. 7 is a collection hole for collecting the separated solvent (plasma).

  As a modified embodiment for performing classification and analysis at the same time, a measurement reagent in the form of powder or solid is preliminarily applied to an area where plasma is separated to react the plasma with the measurement reagent and measure the reaction. By doing so, it is conceivable to analyze plasma. Moreover, as shown in FIG. 8, the measurement sensor 5 may be built in advance at the place where plasma is separated, and measurement may be performed when the plasma flows. Specifically, a method in which the measurement sensor 5 is an enzyme electrode or the like and performs electrochemical measurement is conceivable. If this is the case, the analysis of the solvent (plasma) can be performed simultaneously with the measurement of the particle size of the particles to be measured, and it can be used for various applications.

  In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. .

The perspective view of the particle size measuring device concerning a 1st embodiment. Sectional drawing of the classification unit in the embodiment. The figure which shows an example of the usage method of the classification unit in the embodiment. Sectional drawing which shows the classification | category result of a measuring object particle | grain and a reference | standard particle. The figure which shows the particle size distribution of each component in blood. The perspective view which shows the 1st modification of this invention. The perspective view which shows the 2nd modification of this invention. The top view which shows the 3rd modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Particle size measuring device 2 ... Reference | standard particle 3 ... Classification unit 3A ... Liquid inlet 3B ... Particle classification part 31 ... 1st flat plate member 31a ... 1st flat plate member The surface 32 that forms the particle classification part of the second flat plate member 32a ... the surface 4 that forms the particle classification part of the first flat plate member ... the fixing member

Claims (9)

A mixing step of mixing reference particles having a known particle diameter into a sample liquid containing particles to be measured;
A classification step of classifying the particles to be measured and the reference particles according to their particle sizes by introducing the mixed liquid generated by the mixing step into a gap that causes capillary action and continuously changes;
A measurement step of measuring a particle size of the measurement target particle from a classification result of the measurement target particle and the reference particle; A mixing step of mixing reference particles having a known particle diameter into a liquid sample containing particles to be measured;
A classification step of classifying the particles to be measured and the reference particles according to their particle sizes by introducing the mixed liquid generated by the mixing step into a gap that causes capillary action and changes stepwise;
A measurement step of measuring a particle size of the measurement target particle from a classification result of the measurement target particle and the reference particle;   The particle diameter measuring method according to claim 1 or 2, wherein in the mixing step, a plurality of types of reference particles having different particle diameters are mixed.   The particle diameter measuring method according to claim 1, 2 or 3, wherein the reference particles are colored particles.   The particle diameter measuring method according to claim 1, 2, 3, or 4, wherein the reference particles are polystyrene particles provided with a fluorescent dye. Reference particles having a known particle size mixed in a sample liquid containing particles to be measured,
A mixed liquid composed of the sample liquid and the reference particles is introduced, and includes a classification unit for classifying the measurement target particles and the reference particles,
The classification unit is
A liquid inlet for introducing the mixed liquid;
A particle classifying unit that is provided in communication with the liquid introduction port, introduces the mixed liquid into the inside by capillary action, and separates the measurement target particle and the reference particle according to the particle size;
The particle size measuring apparatus, wherein the particle classifying unit is formed from surfaces facing each other, and a gap between the surfaces facing each other is continuously changed.   The particle size measuring apparatus according to claim 6, wherein the particle classification unit is configured by overlapping a flat plate-like first member and a flat plate-like second member with a spacer interposed at one end. Reference particles with known particle diameters mixed in the liquid containing the particles to be measured,
A mixed liquid composed of the sample liquid and the reference particles is introduced, and includes a classification unit for classifying the measurement target particles and the reference particles,
The classification unit is
A liquid inlet for introducing the mixed liquid;
A particle classifying unit that is provided in communication with the liquid introduction port, introduces the mixed liquid into the inside by capillary action, and separates the measurement target particle and the reference particle according to the particle size;
The particle size measuring apparatus, wherein the particle classifying unit is formed from surfaces facing each other, and a gap between the facing surfaces changes stepwise.   The particle size measuring device according to claim 8, wherein the particle classification unit is configured by overlapping a flat plate-like first member and a second member having a step-like concave groove.