JPH03255936A - Spectrophotometer - Google Patents

Abstract

PURPOSE:To exactly recognize the assigned weight of a sample without correcting a suction weight by providing a sample weight sensor which measures the suction weight of the sample and stopping the suction when the sample of the specified weight is sucked. CONSTITUTION:A test tube 10 contg. the sample 1 is set in a sample holder 2 and a suction nozzle 11 is so positioned as to come into contact with the bottom of a test tube 10. A squeezing pump 6 is then started and the weights of the test tube 10 and the sample 1 are read by the weight sensor 3. The ultimate weight after the previously inputted suction weight is subtrated is determined and thereafter, the pump 6 is run to start the suction of the sample 1. The suction weight of the sample 1 is kept monitored at all times in a weight processing section and a sample control section as well as an absorptivity reading control section 4. The rotation of the pump 6 is stopped and the measurement of the absorbance is started when the ultimate weight is attained. The measurement of the absorbance is executed by leading the light from a light source section 9 to a flow cell 7, detecting the light transmittance thereof in a luminous intensity detecting section 8 and contrasting this transmittance with the previously formed calibration curve of the control section 4 to determine the concn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a spectrophotometer, which is a type of chemical analysis for measuring target components or activity values in a sample.

[Prior Art] Spectrophotometers are used, for example, in visible spectrophotometry, ultraviolet spectrophotometry, etc. - for example, in the food field, such as the analysis of food components, and in blood samples such as lipids and glucose. It is commonly used in a variety of fields, including clinical fields such as component analysis and environmental fields such as water quality analysis.

This principle works by adding a coloring reagent to a sample to develop a color, measuring the degree of decrease in transmitted light (light transmittance) of the sample, converting it into concentration, and comparing it with a pre-prepared calibration curve to determine the target product. This is to find the concentration.

The measurement sample is prepared by dissolving or suspending it in water or an organic solvent.

By the way, a straining pump is used to supply a measurement sample to a spectrophotometer. The reason for using a straining pump is that it is easy to exchange the sample, the sample can be transferred without leaving the tube, and it is less affected by external disturbances such as dirt.

The straining pump moves a liquid sample by arranging a resin tube made of silicone resin or the like along the inner wall of a circumferential wall and rotating a plurality of disks in the center in the same direction.

However, when using a squeezing pump, the squeezing tube tends to collapse as it is used.

Therefore, the amount of sample suction is determined by the rotation time of the squeezing pump, but as the tube deteriorates, the amount of suction decreases even with the same rotation time, and the sample may not reach the flow cell or carryover may increase. There were issues such as: For this reason, in the conventional method, a certain amount of sample is placed in a test tube, the pump is rotated, and the time until the sample runs out, air bubbles enter the flow cell, and the output signal changes, and the rotation time is calculated based on the amount of sample. The amount of suction was corrected by applying a certain coefficient.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, it is not possible to accurately determine the amount of suction without frequent correction, and a certain amount must be accurately sampled. There were issues such as errors in the amount up to and including measurement errors.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art described above, it is an object of the present invention to provide a technique that does not require correction of the amount of sample aspirated and can accurately determine the specified weight of the sample.

[Means for Solving the Problems] In order to achieve the above object, the spectrophotometer of the present invention is a spectrophotometer that uses a straining pump to aspirate a sample, guide it to a flow cell, and measure the absorbance. The present invention is characterized in that it includes a sample weight sensor for measuring the amount of sample aspirated, and means for stopping the aspiration when a specified weight of sample is aspirated.

[Function] According to the configuration of the present invention, a sample weight sensor is provided for measuring the amount of sample aspirated, and a means for stopping the aspiration when a specified weight of sample is aspirated. There is no need to correct the amount of suction, and the specified weight of the sample can be accurately determined.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention. In Figure 1, 1 is a sample, 2 is a sample holder, 3 is a weight sensor,
4 is a weight processing section, a pump control section, and an absorbance reading control section; 5 is a ladder tube; 6 is a ladder pump section;
7 is a flow cell, 8 is an absorbance detection section, 9 is a light source section, 10
1 is a test tube containing a sample, 11 is a suction nozzle, and 12 is a diffraction grating.

The operation of the spectrophotometer according to one embodiment of the present invention constructed as described above will be explained below.

First, the test tube 10 containing the sample 1 is set in the sample holder 2, and the suction nozzle 11 is set so as to hit that part of the test tube IO. Next, at the same time as pressing the start button (not shown) of the squeezing pump unit 6, the weight of the test tube 10 and the sample 1 is read by the weight sensor 3, and the achieved weight is obtained by subtracting the suction weight input in advance. After determining this, the straining pump 6 is rotated and suction of the sample is started.

While the ironing pump 6 is rotating, the suction weight of the sample (sample reduction amount) is constantly monitored by the weight processing unit and the pump control unit 4, and when the weight reaches the final weight, the rotation of the ironing pump 6 is stopped and absorbance measurement begins. do.

To measure the absorbance, light is irradiated from the light source 9 and the diffraction grating 1
2, the light transmittance is detected by the absorbance detection section 8, and this is compared with a calibration curve prepared in advance by the absorbance reading control section 4 to determine the concentration of the target substance.

The prepared sample is usually an aqueous solution, so the weight of the sample (g) = volume of the sample (ml). However, for example, when using an organic solvent with a specific gravity other than 1, the weight of the sample (g) = dx sample capacity (mA') (however,
d represents specific gravity. ). For example, when a sample of v (m/) is aspirated, m=dXv(
g). In this case, the preset value can be set as m or V.

According to the embodiment of the present invention described above, the sample weight sensor 3 is provided for measuring the amount of sample 1 sucked, and the sample weight is constantly monitored by the weight processing section and the pump control section 4, and the sample weight is constantly monitored by the weight processing section and the pump control section 4. Since the apparatus is equipped with a means for stopping suction when the weight of the sample is aspirated, there is no need to correct the amount of sample aspirated, and the specified weight of the sample can be accurately determined.

In addition, in conventional methods, when an autosampler is connected and many samples are run at once, the amount of sample aspirated is corrected first. However, according to the present invention, correction can be made for each sample, so there is no such fear. That is, since correction is performed for each sample, there is no need to correct the suction amount in advance.

Although the present invention has been described with respect to a spectrophotometer that measures absorbance, it can also be applied to other spectrophotometers. In other words, it generates fluorescence or phosphorescence, and this spectrum is widely applied to devices that use diffraction gratings, quartz prisms, optical filters, etc. for analysis such as identification of organic compounds and qualitative analysis of inorganic ions. be able to.

[Effects of the Invention] As explained above, according to the present invention, a sample weight sensor is provided for measuring the amount of sample aspirated, and means is provided for stopping the aspiration when a specified weight of the sample is aspirated. So,
It is possible to perform correction for each sample, eliminate the need to correct the initial amount of sample aspirated, and achieve the excellent effect of accurately determining the designated weight of the sample.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sample, 2... Sample holder, 3... Weight sensor, 4... Weight processing section, pump control section, and absorbance reading control section, 5... Straining tube, 6... Straining pump section , 7... Flow cell, 8... Absorbance detection section, 9... Light source section, 10... Test tube containing sample, 11... Suction nozzle, 12... Diffraction grating.

Claims (1)

[Claims] (1) A spectrophotometer that uses a straining pump to suck a sample, guide it to a flow cell, and measure its absorbance, the spectrophotometer being equipped with a sample weight sensor for measuring the amount of sample sucked, A spectrophotometer characterized in that the spectrophotometer is equipped with means for stopping suction when a weight of a sample is aspirated.