JPH0527656U - Ultra small amount measurement cell - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a structure of an extremely small amount of cell, which is capable of performing accurate measurement equivalent to that of a standard cell of 10 mm and recovering a valuable sample. [Structure] An extremely small amount of cell with a structure in which a sample is sandwiched between two flat plate transmissive windows, and one transmissive window has a cylindrical groove to facilitate sample collection. The structure is such that the sample is inhaled therein. As a result, even if the amount is extremely small, optical correction is possible and a correct measurement result can be obtained. [Effects] According to the present invention, it is possible to provide an extremely small amount cell for a spectrophotometer which can obtain a measurement result equivalent to that of a 10 mm standard cell even in an extremely small amount and can collect a sample.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is mainly used for cutting-edge research and quality control in bioscience such as science, medicine and pharmacy. In particular, it relates to a small amount of cells that are indispensable in the DNA and RNA research departments.

[0002]

[Prior Art]

 The conventional micro-measurement cell has a structure in which a standard square cell of a spectrophotometer, which is 10 mm square, is narrowed in the width direction (cell length remains 10 mm) (for example, cell length 10 mm, width 2 mm) to perform micro-measurement. Was there. With this structure, the minimum measurable sample is 200 μl to 100 μl, and it is not possible to deal with the recent customer requirement of less than 50 μl. Therefore, this microcell structure was improved, a mask for light flux cutting was installed in front of the cell, the cell width of the microcell was further narrowed, and the measurement light was irradiated only to a part near the bottom surface. Cells are the mainstream.

However, customer demand has been further reduced to a very small amount, and recently, a cell capable of measuring 5 μl is required. The 5 μl cell currently used has a structure in which a sample of 5 μl is put in a cylindrical tube with an extremely small inner diameter, the measuring light is condensed by a lens, and the cylindrical tube is irradiated with light for measurement.

However, in this structure, since the cell is a cylindrical tube, the measuring light is affected by the lens action of the cylindrical tube, and there is a big problem that an accurate measurement result cannot be obtained.

[0005]

[Problems to be solved by the device]

 (1) Providing ultra-trace amount cells for spectrophotometers with a structure that enables accurate measurement of even minute amounts of samples.

(2) Providing an extremely small amount cell for a spectrophotometer having a structure capable of recovering a sample after measurement.

[0007]

[Means for Solving the Problems]

 In order to make accurate measurements with a very small amount of sample, it is desirable that the transmission surface of the cell be a flat plate. In addition, it is impossible to make the cell length 10 mm because of the small amount of sample. From the above two points, the cell structure is basically a combination of two flat plates, and the sample is sandwiched between them. Considering the recovery of the sample after measurement, it is easier to recover the groove shape in which the sample is sandwiched than the shallow one. Therefore, the groove shape should be a cylindrical groove with a depth of 0.5 mm to 1 mm (the transmitting surface is It is desirable to make it the bottom of the cylinder). Also, since the measuring light is generally larger than the bottom area of this cylinder, it is necessary to provide a mask with holes on the front surface of the cell which is slightly smaller than this bottom area.

With the cell structure as described above, it is possible to obtain a correct measurement result without disturbing the measurement light even with an extremely small amount of sample, and it is easy to remove the two transmission plates and collect the sample. .. In addition, since it is sealed with two transparent plates, stable measurement results can be obtained without the risk of evaporation of the sample during measurement.

[0009]

[Action]

 Basically, the absorbance of the sample should be a constant value even if the amount is extremely small. If there is a large error between when measuring with a 10 mm square cell and when measuring with a small amount of cell, it is difficult to say that it is a correct measurement. One of the greatest effects of the present invention is that an accurate measurement result can be obtained with an extremely small amount (for example, a sample volume of 5 μl).

For this, the transmission surface must be absolutely flat. If a cylindrical surface is used, it is possible to suppress the measurement light from receiving the lens effect on the cylindrical surface as much as possible (for example, water is added to the cylindrical surface to reduce the change in the refractive index of the incoming and outgoing light on the cylindrical surface). Without it is unsuitable as a spectrophotometer cell. The micro-volume cell of the present invention is a micro-volume cell for a spectrophotometer that has few optical errors and can obtain correct measurement results.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. Fig. 1 shows a conventional cylindrical microvolume cell. When the measurement light beam (2) of the spectrophotometer is incident on the sample, it is desirable that it is a parallel light beam, but most spectrophotometers are incident on the sample at a certain incident angle.

Therefore, if the shape of the cell (1) is cylindrical, light is scattered by the lens action, or the measurement light flux changes, and the size of the light incident on the detector (4) also changes. Then, light may overflow from the light receiving surface (5) and an error may occur in the measured value. Even if the detector (4) is brought close to the cell in order to avoid the danger, the danger of light scattering due to the lens action of the cell is still large.

FIG. 2 shows an embodiment according to the present invention. The cell is composed of two parallel transmission windows A (6) and B (7). The transmission window A is provided in a cylindrical groove (8) for inhaling the sample and has a depth of 0.5 mm and a groove diameter of 3.5 mm. After the sample is sucked into the cylindrical groove, the two transmission windows A and B are stacked and set on the cell block (9). It is fixed by being pressed by a spring (10) from behind the transparent window B, and each cell block is mounted on a cell holder (11). A mask (12) is installed in front of the cell, and the mask has a circular diameter of 2 mm, which is smaller than the area of the bottom surface of the cylindrical groove.

The measuring light has a light beam cut by a mask, and the light passing through the hole diameter is applied to the sample in the cylindrical groove. Depending on the sample, it enters the detector (4). When light enters the cell, the incident light has an angle to the transmission window A, but the transmission surface is flat, so the optical error can be corrected using the correction function of the spectrophotometer. (This can be done in exactly the same way as the optical correction method for a standard angle cell of 10 mm). As described above, even though it is an extremely small amount cell, its optical characteristics are the same as those of the standard angle cell of 10 mm, so it is possible to obtain accurate measurement results with a small amount of sample.

Further, since the sample is completely sealed by being narrowed down by the transmission windows A and B, stable measurement can be carried out without fear of evaporation during the measurement or convection due to air. Further, since the transmission windows A and B are only pressed by the spring, they can be easily separated, and the sample can be collected by inserting a syringe or the like into the cylindrical groove.

[0016]

[Effect of the device]

 The present invention has an extremely small amount of cell structure in which a sample is sandwiched between the above-mentioned flat transmission plates and the sample suction part is formed into a cylindrical groove shape. (1) With the same optical error as the 10 mm standard cell Therefore, it becomes possible to make corrections, and accurate measurement results can be obtained even with an extremely small amount.

(2) The sample after the measurement can be easily collected with a syringe or the like.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional trace amount cell.

FIG. 2 is a view showing an embodiment according to the present invention.

FIG. 3 is a diagram showing a measurement example according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultra small amount cell, 2 ... Measurement light flux, 3 ... Lens, 4 ... Detector, 5 ... Detector light receiving surface, 6 ... Transmission window A, 7 ... Transmission window B,
8 ... Cylindrical groove, 9 ... Cell block, 10 ... Spring, 11 ... Cell holder, 12 ... Mask.

Claims (2)

[Scope of utility model registration request] 1. A measuring cell of a spectrophotometer for measuring transmittance and reflectance of a sample, characterized in that the cell structure is such that a sample can be sandwiched between two flat transmission plates for measurement. Ultra minute amount measurement cell. 2. The trace amount measurement cell according to claim 1, wherein the sample can be collected.