JP2008116314A - Device for measuring trace quantity liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring trace quantity liquid which can analyze a high concentration liquid sample by an optical means, while improving the product yield, using a simpler structure than in the past. <P>SOLUTION: This device for measuring trace quantity liquid comprises at least a light source which emits measurement light for measuring the liquid sample, a first optical fiber which guides light emitted from the light source, a second optical fiber which is arranged on the same optical axis as the first optical fiber and arranged so as to oppose to the end face of the first optical fiber. The interval between the first optical fiber and the second optical fiber is such an interval that the liquid sample keeps a spherical shape due to surface tension, when dropping the liquid sample to be measured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a minute amount liquid measuring apparatus for measuring components and concentrations of a minute amount of liquid sample.

  2. Description of the Related Art Conventionally, a measurement method using a rectangular or cylindrical optical cell is generally known as a liquid sample measuring apparatus for optically analyzing and measuring a liquid sample. In this method, a sample to be measured (liquid sample) is injected into a square cell, measurement light is incident from one surface of the cell, and this light passes through the liquid sample and is output from the other cell surface. Is received by a light receiving element, and the component and concentration in the liquid sample are measured by measuring the change in the spectrum of the light and the absorbance.

  By the way, in such analysis of components and concentrations of liquid samples, in recent years, there has been an increasing demand for analysis of components and concentrations contained in extremely small amounts of liquid samples such as droplets. However, a measurement cell used in a conventional absorptiometric analyzer or the like requires a sample of a certain amount or more, and there is a problem that it is impossible to measure such a very small amount of sample as a droplet.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a minute amount liquid sample measuring apparatus capable of analyzing components and concentrations contained in an extremely small amount of liquid sample by a simple method. It is.

In order to solve the above-mentioned problem, the present invention as claimed in claim 1 is characterized in that a pair of V-grooves for fixing and arranging coaxially with the end faces of a pair of optical fibers facing each other, and a minute amount between the pair of V-grooves A liquid sample holder provided with a circular opening for holding a droplet and a circular opening provided between a pair of V-grooves were fixedly arranged coaxially with the end faces facing each other. A pair of optical fibers, the measurement light is incident on the droplet held in the circular opening from one end surface of the optical fiber, and the light transmitted through the droplet is received by the other end surface of the optical fiber. The gist is to send to the optical processing means and measure the component and concentration of the droplet.
The present invention described in claim 2 is the micro liquid measuring device according to claim 1, wherein the circular opening provided between the pair of V-grooves is a penetrating cylindrical hole. To do.

  According to a third aspect of the present invention, there is provided excitation light output means for emitting excitation light for exciting a droplet component from a direction perpendicular to the optical axes of a pair of optical fibers, and the excitation light output means is excited by the excitation light output means. The gist is that the received light is received by a pair of optical fibers and sent to the optical processing means to measure the component and concentration of the droplet.

  The present invention according to claim 4 is a pair of V grooves for fixing and coaxially arranging the end faces of a pair of optical fibers facing each other, and an interval at which droplets can be held between the pair of V grooves. And a pair of optical fibers fixedly arranged coaxially with the end faces facing each other, and a pair of optical fibers arranged with the end faces opposed to each other between the pair of V grooves from one end face of the optical fiber The measurement light is incident on the droplet held between the two end faces, and the light transmitted through the droplet is received by the other end face of the optical fiber and sent to the optical processing means to measure the component and concentration of the droplet. The gist.

  According to the present invention, even a liquid sample having an extremely small amount of droplets can measure the components and concentration contained in the liquid, so that a large amount of sample such as a biological sample can be collected. Even in difficult cases, the components and concentration can be measured.

  In addition, since the amount of sample necessary for the measurement may be small, there are few problems in the disposal of the sample after the measurement.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a micro liquid measurement device according to the present invention, and FIG. 2 is an enlarged perspective view in which a measurement portion of a liquid sample provided in a measurement path of the micro liquid measurement device is enlarged.

  As shown in FIG. 1, the micro liquid measurement device is provided on the same optical axis as the light source 13, the first optical fiber 10 that guides the light emitted from the light source 13, and the first optical fiber 10. The second optical fiber 11 and at least a spectroscope 14 connected to the other end of the second optical fiber 11 are configured.

  Here, the light source 13 is appropriately selected depending on the characteristics of the liquid sample to be measured, and a light source that outputs visible light or near infrared light is used. In this embodiment, a white LED is specifically used, but any light source such as a halogen lamp, a broadband laser, and a fluorescent light source can be applied.

  Examples of the first and second optical fibers 10 and 11 include silica-based optical fibers and plus-chip optical fibers. In this embodiment, plastic clad quartz core fibers having high portability and high bending durability are used.

  An interval is provided between the first optical fiber 10 and the second optical fiber 11 such that when the liquid sample to be measured is dropped, the liquid sample retains a spherical shape due to surface tension.

  The spectroscope 14 has a function of spectrally analyzing the wavelength of light output from the light source 13 and transmitted through the liquid sample. The spectroscope 14 includes a data storage function, a data analysis function (program), an analysis result display function (display), and the like in addition to the spectroscopic function. In this embodiment, a CCD linear sensor having a measurement wavelength range of 350 to 1050 nm as a light receiving element for detecting transmitted light, and a wavelength resolution of 0.3 to 10.0 nm (the resolution is opened). A personal computer (PC) equipped with an analysis function that can be processed with a caliber) is used.

  When performing measurement with a micro liquid measuring device having such a configuration, first, a liquid sample is gently dropped with a dropper or the like between the first optical fiber 10 and the second optical fiber 11, and the liquid sample It is held in a spherical state by surface tension. In this state, output of measurement light from the light source 13 is started. This light is guided in the first optical fiber, and when it reaches the droplet sample, a part of the light is absorbed and the remaining light enters the second optical fiber and guides the inside of the fiber to the spectroscope 14. To reach. The light received by the spectroscope 14 is subjected to processing such as component analysis and concentration detection by a data analysis program.

  FIG. 3 shows a modified example of the above-mentioned minute amount liquid measuring apparatus. This micro-volume liquid measuring device has (1) a liquid sample that emits fluorescence when absorbing a specific wavelength is held in advance between the first optical fiber and the second optical fiber, and (2) It is possible to provide excitation light output means for irradiation (not shown), and (3) to connect the spectroscope 14 to the output ends of the first and second optical fibers. The configuration is different from the measuring device.

  When performing measurement with this micro-volume liquid measuring device, excitation light is applied to the liquid sample from the excitation light output means with the liquid sample held in a spherical shape between the first optical fiber and the second optical fiber. Irradiation, fluorescence from the liquid sample generated by this irradiation is guided into the first and second optical fibers 10 and 11 and guided to the spectroscope 14, and the spectroscope 14 performs the fluorescence spectrum analysis.

  Here, you may make it fix between the 1st and 2nd optical fibers 10 and 11 of the micro amount liquid measuring apparatus mentioned above to the fixing board 12 as shown in FIG. The fixing plate 12 is provided with a V-groove 12a for preventing the movement of the optical fiber in advance and a liquid retaining portion for retaining a spherical shape when a liquid sample is dropped. When the first and second optical fibers 10 and 11 are fixed to the fixing plate 12, a configuration as shown in FIG. 5 is obtained. When a liquid sample is further dropped, the configuration shown in FIG. 6 is obtained. Since the first and second optical fibers 10 and 11 can be fixed by providing the fixing plate 12 in this way, the measurement accuracy can be stabilized, and the spherical shape of the liquid sample can be maintained by providing the liquid retainer 12b. Can do.

  Next, FIG. 7 shows the result of measuring the intensity dependency with respect to the change in the distance between two optical fibers arranged opposite to each other. In this measurement graph, the horizontal axis represents distance (μm), and the vertical axis represents absorption intensity. In this measurement, a positive chip clad quartz core fiber having a diameter of 1 mm (φ1 mm) was used as the first optical fiber 10 and the second optical fiber 11.

  In this measurement, nothing was dripped, that is, the measurement of air was used as a reference (▲ mark) and compared with the result of water measurement (♦ mark). As a result, it was shown that the strength was higher overall when water was measured. It was also shown that the strength does not depend much on the separation distance. Therefore, in the following measurement, an experiment was performed with a separation distance of 500 μm in consideration of workability in manufacturing the apparatus.

  FIG. 8 shows the results of measuring the strength dependence on the optical fiber separation distance using rhodamine as the liquid sample. In this measurement, rhodamine 0.04 mmol (■ mark), rhodamine 0.1 mmol (♦ mark), rhodamine 1 mmol (▲ mark), and water (● mark) were used.

  As a result, it was shown that the strength decreases as the separation interval increases. Further, when the absorbance of each of the above rhodamines was measured using the water intensity shown in FIG. 8 as a reference, the transmittance shown in FIG. 9 was obtained. From this result, it can be found that each solution has a correlation.

  The rhodamine absorption measurement was performed using the minute amount liquid measuring apparatus of FIG. The result is shown in FIG. In this measurement graph, the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the absorption intensity. A white LED was used as the light source, and 1 mmol of rhodamine was used as the liquid sample. As a comparative example, measurement was performed under the same conditions as in the case of air and water. Measurement was performed using a plastic optical fiber having a diameter of 0.5 mm (φ0.5 mm) as the first optical fiber 10 and the second optical fiber 11.

  In the same figure, graph (1) shows the results for air, graph (2) for water, and graph (3) for rhodamine 1 mmol. As can be seen from the graph, it can be seen that there is a large absorption at 500 to 600 nm.

  Next, an experiment was performed in which a liquid sample was excited using excitation light and the generated fluorescence spectrum was measured using the micro-volume liquid measuring apparatus shown in FIG. Measurement was performed using a green LED having a peak wavelength of 525 nm as an excitation light source. The result is shown in FIG. According to this, the appearance of a small spectrum in the 525 nm band was confirmed, but the spectrum in the 600 nm band generated by excitation could be clearly confirmed. Thus, it was shown that the fluorescence spectrum can be measured using the micro-volume liquid measuring device shown in FIG.

  Next, using a plastic optical fiber having a diameter of 1.0 mm (φ1.0 mm), the intensity dependency when the distance between the two optical fibers was changed was measured. FIG. 12 is a graph showing the fluorescence spectrum of rhodamine used in the measurement, and shows the results when measured at a concentration of 1 mmol and a separation distance of 0.5 mm. FIG. 13 shows the experimental results in which the separation distance was changed stepwise using this rhodamine. As shown in the figure, when the separation distance is 0.3 mm or less, the distance is too narrow and the excitation light is not applied to the entire liquid sample and sufficient fluorescence intensity cannot be obtained. Was detected. In particular, the intensity changes abruptly at a position changing from 0.3 mm to 0.4 mm, and excitation light is hardly detected after 0.4 mm, and excitation light is almost radiated to the outside after 0.4 mm. It was shown that only fluorescence was detected.

  From the above results, according to the present invention, it was shown that a very small amount of liquid sample can be measured with a very simple configuration as shown in FIGS. This configuration is particularly effective when measuring a liquid sample having a high concentration.

  Moreover, since it is a simple structure and does not require special processing as described above, it is possible to suppress the component cost and the manufacturing cost, and as a result, the yield can be improved.

It is a whole lineblock diagram of a micro quantity liquid measuring device concerning an embodiment of the invention. It is the expansion perspective drawing which expanded the measurement part of the liquid sample provided in the measurement path | route of a micro amount liquid measuring apparatus. It is a figure which shows the modification of the trace amount liquid measuring apparatus of this invention. It is a figure which shows the structure of the fixing plate 12 which fixes a 1st and 2nd optical fiber. It is a figure which shows the state which has arrange | positioned the 1st and 2nd optical fiber to the fixing plate. It is a figure which shows the state which dripped the liquid sample between the 1st and 2nd optical fibers. It is a graph which shows the result of having measured the intensity change at the time of changing the separation distance between the 1st and 2nd optical fibers. It is a graph which shows the result of having measured the intensity change at the time of changing the separation distance between the 1st and 2nd optical fibers using the liquid sample (rhodamine) of a different density | concentration. It is a graph which shows the result of the transmittance | permeability computed based on the result of FIG. It is a graph which shows the result of having measured the intensity | strength dependence with respect to a wavelength, using water, air, and a liquid sample (rhodamine) as a liquid sample. It is a graph which shows the result of having measured the intensity dependence with respect to a wavelength using a plastic optical fiber (diameter 0.5mm). It is a graph which shows the result of having set the separation distance of the optical fiber which opposes to 0.5 mm, and measuring the intensity dependence with respect to a wavelength. It is a graph which shows the result of having measured the intensity | strength dependence with respect to a separation distance, using green LED as excitation light.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st optical fiber 11 ... 2nd optical fiber 12 ... Fixed plate 12a ... V groove 12b ... Liquid retaining 13 ... Light source 14 ... Spectroscope

Claims (4)

A pair of V-grooves are arranged to be coaxially fixed with the end faces of the pair of optical fibers facing each other, and a circular opening for holding a minute amount of liquid droplets is provided between the pair of V-grooves. A liquid sample holder;
Through the circular opening provided between the pair of V-grooves, the pair of optical fibers fixedly arranged coaxially with the end faces facing each other,
Measuring light is incident on the droplet held in the circular opening from one end surface of the optical fiber, and the light transmitted through the droplet is received by the other end surface of the optical fiber to the optical processing means. An apparatus for measuring a small amount of liquid, wherein the apparatus measures the composition and concentration of the droplets.   2. The minute liquid measuring apparatus according to claim 1, wherein the circular opening provided between the pair of V-grooves is a penetrating cylindrical hole. Excitation light output means for emitting excitation light for exciting the component of the droplet from a direction perpendicular to the optical axis of the pair of optical fibers,
An apparatus for measuring a small amount of liquid, wherein light excited by the excitation light output means is received by the pair of optical fibers and sent to an optical processing means to measure the component and concentration of the droplet. A pair of V-grooves for fixing and coaxially facing the end faces of the pair of optical fibers;
The pair of optical fibers provided with a space between the pair of V grooves so that droplets can be held, and having the end faces opposed to each other and fixed coaxially,
From one end surface of the optical fiber, measurement light is incident on the droplet held between the end surfaces of the pair of optical fibers disposed with the end surfaces facing each other between the pair of V grooves, A micro liquid measurement device characterized in that the transmitted light is received by the other end face of the optical fiber and sent to an optical processing means to measure the component and concentration of the droplet.

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