JP5297262B2 - Dispensing instrument verification method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inspecting a dispensing implement having high accuracy. <P>SOLUTION: After a detection solution 3A, containing a second coloring matter component, is injected in an absorbance-detecting container 11, in which a standard solution 11A containing a first coloring matter component is housed from the dispensing implement 3 to be detected to prepare a mixed solution, absorbance of the mixed solution is detected. By utilizing the first and second coloring matter components not being reduced by the evaporation phenomenon during the period, the detection value V<SB>s</SB>of the dispensing solution amount of the dispensing implement 3 is calculated, to thereby obtain inspection result of high accuracy. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a dispenser verification method and apparatus, and in particular, enables the dispensing amount of a dispenser to be verified to be verified closer to a true value.

  A pipetter that draws a sample liquid from one sample container in a minute amount (for example, 1 to 1000 [μl]) and separates it into one sorting container, or a plurality of small amounts of the same liquid sucked from one sample container. Air displacement type liquid aspirator (such as a dispenser that continuously dispenses into a dispenser, or a diluter that aspirates different liquids from two sample vessels and mixes them in one dilution vessel) Is conventionally used.

  Since this type of dispensing device performs a suction operation for a minute amount of liquid, the user needs to dispense a predetermined amount of liquid prior to actual use in order to aspirate a predetermined amount of liquid. It is necessary to perform an operation of calibrating after verifying the amounts one by one (see Patent Documents 1 to 3).

JP 2008-76393 A JP 2002-286591 A Japanese Patent No. 2520852

  As a method for verifying the dispensing amount of a dispensing device that aspirates a minute amount of liquid, the standard of ASTM standardized in 1989 and ISO 8655 standardized in 2002 were used as guidelines, and the weight of the sucked liquid was weighed. The gravimetric method is used, and this weight method is used for the verification of dispensing instruments as a standard reference.

  This weight method uses a technique in which the weight of the sucked liquid is discharged into a sample container of a balance, the weight is measured, and then converted into a volume.

  Therefore, the calibration based on the gravimetric method is actually affected by the fact that the dispensed liquid discharged into the sample container of the balance evaporates into the atmosphere in the process of measuring the weight. By performing the work in a room with a special test environment in which the humidity is adjusted to about 60 to 70 [%], a device has been devised to suppress the evaporation amount.

  However, even in the case of a dispensing device that has been certified under this special calibration environment condition, the actual working environment in which the liquid is dispensed using this is not necessarily limited to the calibration environment (i.e., the humidity is low). In general, the dispensing operation is performed in an environment having a humidity as low as, for example, 30 to 45%.

  Therefore, even with a dispensing instrument that has been tested by the gravimetric method under special test environment conditions, it is not always possible to quantitatively dispense a liquid with the dispensed quantity determined.

  The present invention has been made in consideration of the above points, and the dispensing amount in the actual working environment of the verified dispensing instrument is obtained by performing the verification process of the dispensing instrument using the optical weighing type verification means. However, the present invention intends to propose a method and apparatus for testing a dispensing instrument that can perform a test so as to be close to a true value.

In order to solve such a problem, in the present invention, in the assay method and apparatus of the dispensing instrument 3 that draws a sample liquid and separates a predetermined dispensing amount, the dispensing solution is used with a reference wavelength of 730 [ nm]. ] Is absorbed by the dispensing device 3 into the absorbance detection container 11 containing the first dye component 11A containing the first dye component having the first absorbance characteristic Q1 that absorbs the light and the reference wavelength 730 [ nm ]. second detection solution 3A make the injected liquid mixture containing a dye component, reference fluid 11A detects the absorbance of the mixed solution having a second absorbance characteristics Q2 which absorbs light of a different wavelength 520 [nm] The liquid volume V _S of the detection liquid 3A is calculated on the basis of the ratio of the absorbance A _B of the liquid and the absorbance A _S of the detected mixed liquid and the known liquid volume of the reference liquid 11A. to determine a test value of the amount V _S To do.

According to the present invention, since making the mixture by injecting a detection solution containing a second pigment component from the dispensing device to be detected absorbance detecting containers reference fluid enters comprising a first dye component, first The ratio of the first and second absorbance detection outputs is obtained, and the absorbance of the mixed solution is detected by obtaining the amount of the detection solution as a dispensed amount based on the ratio and the known amount of the reference solution. By using the fact that the first and second pigment components are not decreased depending on the evaporation phenomenon until the time point, the detection value of the dispensing liquid amount of the dispensing device is obtained, so that high accuracy can be obtained. The test result can be obtained.

It is a block diagram which shows the dispensing instrument test | inspection apparatus by one embodiment of this invention. It is a rough-line perspective view which shows an absorbance detection container. It is a characteristic curve figure which shows the light absorbency characteristic of a reference | standard liquid. It is a characteristic curve figure which shows the light absorbency characteristic of a liquid mixture. It is a front view which shows the test object dispensing instrument. It is a flowchart which shows a verification / calibration process procedure. It is a basic diagram which shows the experimental data of the comparative example with a gravimetric method. It is a chart which shows average value data as experimental data of a comparative example. It is a basic diagram with which it uses for description of the evaporation phenomenon in a gravimetric method test | inspection. It is a basic diagram with which it uses for description of the influence of the evaporation phenomenon about a 1000 [microliter] dispensing instrument. It is a basic diagram with which it uses for description of the influence of the evaporation phenomenon about a 1000 [microliter] dispensing instrument. It is a basic diagram with which it uses for description of the influence of the evaporation phenomenon about a 100 [microliter] dispensing instrument. It is a basic diagram with which it uses for description of the influence of the evaporation phenomenon about the dispensing instrument of 10 [microliters].

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) Configuration of Dispensing Instrument Verification Device In FIG. 1, 1 indicates a dispensing instrument verification device as a whole, and includes an verification device body 2 and a verification target dispensing device 3.

  The casing 10 of the verification apparatus main body 2 is provided with a detection container setting groove 12 for positioning and storing the absorbance detection container 11, and the white light source light L1 emitted from the light source means 13 is detected by the blank light filter 14A of the filter means 14 or the detection light. The transmitted light L2 that has passed through the filter 14B and entered the absorbance detection container 11 and passed through the absorbance detection device 11 is incident on the photoelectric conversion means 15.

As shown in FIG. 2, the absorbance detection container 11 is constituted by a cylindrical transparent glass container. As shown by an absorbance curve Q1 in FIG. 3 from the white light source light L1, the absorbance detection container 11 has a predetermined wavelength (730 in this embodiment). A reference solution 11A containing a blue pigment component that absorbs [nm] wavelength) is prepared in a state where a predetermined reference solution amount is injected.

When the absorbance detection container 11 having such a configuration is set in the detection container setting groove 12, the dispensing port 11B provided at the upper end is held in a state of being exposed to the outside of the housing 10, thereby the dispensing port. In contrast to 11B, a detection liquid 3A sucked as a dispensing liquid by the assay target dispensing instrument 3 can be injected into the absorbance detection container 11.

  The detection liquid 3A includes a red dye component having an absorption wavelength (520 [nm] in this embodiment) different from the dye component (blue) of the reference liquid 11A.

  Thus, when the detection liquid 3A is injected from the assay-target dispensing device 3, the absorbance detection container 11 mixes it with the reference liquid 11A, so that the absorbance based on the dye component of the reference liquid 11A is obtained as shown in FIG. In addition to the curve Q1, the absorbance characteristic such that the absorbance curve Q2 (wavelength 520 [nm]) of the detection solution 3A is generated at a wavelength position away from the wavelength position of the absorbance curve Q1 (wavelength 730 [nm]) of the reference solution 11A. Will be presented.

  The filter means 14 includes a blank light filter 14A and a detection light filter 14B. When only the reference liquid 11A is contained in the absorbance detection container 11, the filter means 14 performs blank light by a rotating mechanism 21A that is switched by the filter switch 21. By inserting the filter 14A on the transmission axis of the light source light L1, only the light component of the absorbance curve Q1 of the reference solution shown in FIG. 3 is taken out and made incident on the absorbance detection container 11.

On the other hand, in the state in which the detection liquid 3A is injected from the verification target dispensing device 3 into the absorbance detection container 11 and mixed with the reference liquid 11A, the filter means 14 detects the detection light by the rotation mechanism 21A of the filter switch 21. By inserting the filter 14B on the transmission axis of the light source light L1, only the light component including the absorbance curve Q2 of the detection liquid 3A in FIG. 4 is extracted and made incident on the absorbance detection container 11.

Thus, the transmitted light L2 transmitted from the absorbance detection container 11 is incident on the photoelectric conversion means 15 when the blank light filter 14A is interposed, including the light component of the absorbance curve Q1 of the reference liquid 11A in FIG. it allows the photoelectric conversion unit 15 outputs the detection outputs S1 representing the absorbance a _B, and supplies it to the central processing unit (CPU) 25 of the microcomputer configuration.

When the transmitted light L 2 passing through the photometric detection chamber 11 in a state where the reference solution 11A is detected liquid 3A mixed hand is incident on the photoelectric conversion unit 15, the photoelectric conversion unit 15 of the detection solution 4 by outputting a detection output S1 corresponding to the absorbance _{a S} of the absorbance curve Q2, to supply it to the CPU 25.

  CPU25 is the following formula

The injection amount V _S of the detection liquid 3A is calculated based on the above, and the calculation result is displayed as a test value on the display means 27 via the system bus 26.

Equation (1) indicates that the injection volume V _S of the detection liquid 3A is a value obtained by multiplying the liquid volume V _B of the reference liquid 11A by the ratio of the absorbance A _S of the detection liquid 3A to the absorbance A _B of the reference liquid 11A. It represents what can be determined.

The ratio of the absorbance A _S of the detection solution 3A to the absorbance A _B of the reference solution 11A, since it represents the dilution of the detection liquid 3A for the reference solution 11A, the injection amount V _S of the detection fluid 3A is previously absorbance This represents that the ratio is determined as the ratio of the injection amount of the detection liquid 3A to the liquid amount of the reference liquid 11A that has been placed in the detection container 11.

  In the case of this embodiment, as shown in FIG. 5, the test object dispensing instrument 3 is provided with a piston portion 31 </ b> C in which a piston is operated by a piston drive portion 31 </ b> B in a device main body portion 31 </ b> A having a tapered cylindrical shape. When the finger operation part 31E is pushed downward with another finger while the finger rest part 31D is sandwiched between fingers, the transmission shaft part 31F transmits the pushing force to the piston drive part 31B, thereby moving the piston part 31C downward. Operate the piston.

  At this time, the piston portion 31C is configured to discharge the air in the suction portion 31G downward through the tip portion 31H fitted at the tip thereof through the conical annular suction portion 31G connected to the lower end portion.

  In this state, when the user loosens the pressing force on the suction operation portion 31E, the suction portion 31G sucks the air in the tip portion 31H into the piston portion 31C by moving the piston portion 31C upward by the spring action of the piston drive portion 31B. Thus, the liquid to be dispensed from the tip of the tip portion 31H is sucked into the tip portion 31H.

  Thus, the verification object dispensing instrument 3 sucks the liquid to be dispensed from the sample container and discharges it as the detection liquid 3A to the absorbance detection container 11 of the dispensing instrument verification apparatus 1 (FIG. 1), thereby the verification target dispensing instrument. 3 is supplied to the verification apparatus main body 2 with a predetermined amount of the detection liquid 3A scheduled in advance, whereby the verification of the amount of the liquid distribution is performed.

  In the above configuration, the CPU 25 enters the verification / calibration processing procedure RT1 shown in FIG. 6 when an execution command for verification / calibration processing is given from the input means 35, and in step SP1, the reference solution 11A is placed in the detection container setting groove 12. It waits for the absorbance detection container 11 in which is placed to be set.

  When the CPU 25 confirms that the absorbance detection container 11 has been set, the CPU 25 moves to the next step SP2 to give a switching control signal S11 from the control means 36 to the filter switching device 21, whereby the blank optical filter 14A of the filtering means 14 is obtained. Is set as the transmission light path of the light source light L1, and the light source control unit S provides the light emission control signal S12 to the light source means 13 in the next step SP3, thereby emitting the white light source light L1.

At this time, the blank light filter 14A extracts the light component of the absorbance curve Q1 (FIG. 3) with respect to the reference liquid 11A contained in the absorbance detection container 11 from the light source light L1, and transmits through the reference liquid 11A in the absorbance detection container 11. by causing the light L2, the photoelectric conversion unit 15 sends a detection output S1, the absorbance _{a B} of the reference liquid 11A, CPU 25 takes in this internal memory in step SP4.

  Subsequently, the CPU 25 moves to step SP5 and sets the detection light filter 14B in the transmission light path of the light source light L1 by giving the switching control signal S11 from the control means 36 to the filter switch 21 and then in step SP6 the absorbance detection container. 11 waits for the detection liquid 3A to be injected from the test subject dispensing device 3.

When the detection liquid 3A is eventually injected into the absorbance detection container 11 and the color of the liquid mixture in the absorbance detection container 11 changes, the CPU 25 obtains the component of the absorbance curve Q2 of the detection liquid 3A in the transmitted light L2. by, by generating a detection output S2 of the photoelectric conversion unit 15 corresponding, CPU 25 is moved to the next step SP7 taking the absorbance a _S of the detection fluid in an internal storage memory.

Thus the absorbance _{A B} at a wavelength of 730 [nm] for the reference solution 11A, by absorbance _{A S} was obtained at a wavelength of 520 [nm], CPU 25, by calculating the equation (1) at step SP8 The injection amount of the detection liquid 3A is calculated, and the injection amount of the detection liquid is displayed on the display means 27 in step SP9 to notify the user.

  Thereafter, by turning off the light source means 13 in step SP10, the CPU 25 ends the verification process for the verification target dispensing instrument 3 in which the detection liquid 3A is injected into the absorbance detection container 11.

  Thereafter, the user needs to calibrate the verification target dispensing instrument 3 by adjusting the piston amount of the piston drive unit 31B of the verification target dispensing instrument 3 (FIG. 5) based on the display on the display means 27 in step SP11. Thus, the CPU 25 ends the verification / calibration processing procedure RT1 in the next step SP12.

  According to the above configuration, the detection liquid 3A dispensed by being sucked into the tip portion 31H and injected into the absorbance detection container 11 in the test-target dispensing instrument 3 (FIG. 5) is applied during the dispensing operation. In addition, since the dye component does not evaporate, the amount of the dispensed liquid of the detection liquid 3A can be tested without being affected by the evaporation phenomenon.

  Incidentally, during the dispensing operation by the dispensing instrument verification apparatus 1 in FIG. 1, the pigment component contained in the reference liquid 11A and the detection liquid 3A is in principle evaporated due to the ambient humidity. Because it is possible to perform the verification by an optical weighing method, the verification operation is performed in a sufficiently low humidity environment, for example, about 30 to 45% in an actual working environment in which dispensing work is performed. However, it is possible to obtain a stable test result without introducing a test error into the test result.

  Such an effect is clearly supported by a comparative example with the results of the gravimetric assay described below.

(2) Comparative Example with Gravimetric Method FIG. 7 and FIG. 8 are comparative examples of experimental results between the calibration result of the gravimetric method and the verification result according to the configuration of the above-described embodiment regarding the evaporation of the dispensing liquid. Is shown.

  The experimental conditions are that the humidity in the test environment is 60 [%], 45 [%] and 30 [%], a manual pipettor is used as the test subject dispensing instrument 3 shown in FIG. In each of the optical weighing methods, 10 points were measured three times each.

  In order to emphasize the comparative theory of accuracy and precision, pipetter linearity was specifically excluded from the discussion.

  As pipetters, 1000 [μl], 100 [μl] and 10 [μl] were used, which are calibrated at a humidity of 60 [%], as currently used when calibrating the pipettor.

  In order to confirm the magnitude of the evaporation value, experimental data was taken without correcting the substantial evaporation amount.

  The experimenter was performed by one person in consideration of individual deviation.

  7 and 8, the magnitude of the variation of the 10-point experimental results in each experiment is represented by the size of one bubble, and the center point represents the accuracy of the bubble as an average value.

  The first data DT1 in FIG. 7 and FIG. 8 represents experimental data when a dispensing solution of 1000 [μl] is collected using a 1000 [μl] pipettor.

  The second experimental data DT2 shows experimental data when a 500 [μl] dispensing solution is collected using a 1000 [μl] pipettor.

  Similarly, the third and fourth experimental data DT3 and DT4 show experimental examples in which 100 [μl] and 10 [μl] dispensing solutions were collected using a 100 [μl] pipettor. The sixth experimental data DT5 and DT6 show experimental examples in which 10 [μl] and 1 [μl] dispensing solutions were collected using a 10 [μl] pipettor.

  In the experimental examples of FIG. 7 and FIG. 8, the first thing to be confirmed is that the gravimetric value is the above-mentioned optical measurement at all humidity over a dispensed amount from 1000 [μl] to 1 [μl]. The accuracy is lower than the method.

  This is because the evaporation of the pigment component does not occur in the case of the optical weighing method as in the above-described embodiment, whereas the evaporation on the balance lowers the calibration value in all the experimental results in the case of the gravimetric method. It represents that.

  Incidentally, since the dye used in the optical measurement method does not evaporate, it can be understood that the amount of the dispensed liquid at the time of dispensing is expressed as it is.

  As for the accuracy, as shown in the bubble graph, which shows the size of the variation in diameter, the accuracy in the gravimetric assay results is low, especially for dispensed liquids with a small volume. I can read.

  As shown in FIG. 9, the accuracy of the calibration by the gravimetric method is low, as shown in FIG. 9, in the gravimetric assay, an operation of dispensing the dispensing solution on the balance using the dispensing device 3 to be assayed such as a pipetter. This is thought to be due to the evaporation phenomenon of the dispensed liquid occurring in the meantime.

  That is, as shown in FIG. 9 (A), the sample liquid 42 in the sample container 41 is sucked into the tip part 31H as the dispensing liquid 43 by the test object dispensing instrument 3, and the liquids shown in FIGS. During the operation of separating the sample container 45 of the balance 44 as shown in FIG. 3), the verification target dispensing device 3 sucks the dispensing liquid 43 into the tip portion 31H due to the negative pressure generated in the tip portion 31H. The dispensed liquid 43 is evaporated internally.

  When the “internal evaporation phenomenon” (referred to as EIP / Evaporation Inside Pipetter) occurs in this way, the liquid 43 expands to a volume of about 800 times due to vaporization of the dispensing liquid 43, so that the tip portion 31H As a result, the suction amount is reduced by the pressure due to the expansion.

  The internal evaporation phenomenon (EIP) caused by the suction of the dispensing liquid 43 in the tip 31H of the test object dispensing instrument 3 is, in other words, from the sample suction during the operation of FIGS. 9 (A) to (C). It occurs until it is discharged.

  In the gravimetric assay, the dispensing solution 43 separated by suction by the assay-target dispensing device 3 is discharged into the sample container 45 as shown in FIG. 9D, and the balance 44 is thereby discharged. The weight of the dispensing solution 43 is measured.

  However, when the dispensing liquid 43 is discharged from the tip portion 31H of the verification target dispensing device 3 to the sample container 45 on the balance 44, the dispensing liquid 43 can be evaporated from the sample container 45 to the outside air. The occurrence of an evaporation phenomenon called “evaporation phenomenon on a balance” (this is called EOB / Evaporation On Balance) is inevitable.

  The evaporation on the balance that occurs during the calibration operation occurs regardless of the amount of the dispensing solution 43 separated by the dispensing device 3 to be assayed, but the dispensing amount is very small. In some cases, it greatly affects the accuracy error in the test results.

  The influence of the evaporation phenomenon on the balance on the verification accuracy can be clearly read in the comparative example with the gravimetric method shown in FIGS.

  From the experimental results shown in FIGS. 7 and 8, the gravimetric test results are affected by the evaporation phenomenon (EOB) on the balance. The dosage is also low.

  On the other hand, when the optical metering type dispensing instrument verification device 1 according to the above-described embodiment is used, the amount of the dye component contained in the reference liquid 11A (FIG. 2) and the verification target dispensing instrument. The amount of the dye component contained in the detection liquid 3A sucked by 3 does not cause a phenomenon that the amount of the dye component decreases due to the evaporation phenomenon.

  Accordingly, the evaporation phenomenon (EOB) on the balance described above with reference to FIG. 9D directly reduces the accuracy of the test result as a decrease in the weight of the dispensing solution, whereas such a test. The cause of the decrease in accuracy does not occur in the assay of the dispensed liquid amount by comparing the absorbance based on the amount of the dye component.

  This can be clearly read from the experimental results of the comparative example with the gravimetric method of FIG.

  It can be clearly read from FIGS. 10 and 11 that the optical metering system is also affected by the internal evaporation phenomenon (EIP).

  FIG. 10 is an enlarged view of the test data DT1 and DT2 for 1000 [μl] of the test target dispensing device 3 in FIG. 7, and FIG. 11 is a diagram of FIG. By omitting the depiction of the experimental data in [%], the experimental data by the gravimetric method behind it can be seen.

  According to FIGS. 10 and 11, both the gravimetric method and the optical weighing method are accurate as the humidity becomes 60%, 45%, and 30% based on the internal evaporation phenomenon (EIP). It can be seen that the accuracy of the test result of the optical weighing method without the evaporation phenomenon on the balance is high based on the evaporation phenomenon (EOB) on the balance.

  Further, the test value based on the weight method of 60% humidity appears near the test value of the optical measurement method of 30% humidity.

  It is clear that this is approximated as a phenomenon, but if it is a test value when validation is required, the humidity difference between 60% and 30% is not theoretically consistent. Understandable.

  The 60% humidity gravimetric test without evaporation correction does not compensate for the accuracy that occurs at the actual dispensing site under 30% humidity, and determines the accuracy tolerance. The result is crazy.

  FIG. 12 and FIG. 13 are enlarged views of experimental results for 100 [μl] and 10 [μl] dispensing instruments, both of which have a difference due to humidity.

  In addition, the smaller the dispensed amount, the lower the precision of the gravimetric method that undergoes the evaporation phenomenon (the diameter of one bubble is larger), and the limitations of the gravimetric method are revealed.

  The present invention can be used for verification of a dispensing instrument such as a pipetter.

  DESCRIPTION OF SYMBOLS 1 ... Dispensing instrument test | inspection apparatus, 2 ... Test | inspection apparatus main body, 3 ... Test target dispensing instrument, 3A ... Detection liquid, 10 ... Housing, 11 ... Absorbance detection container, 11A ... Reference | standard liquid, 11B: Dispensing port, 12 ... Calibration container setting groove, 13 ... Light source means, 14 ... Filter means, 14A ... Blank light filter, 14B ... Detection light filter, 15 ... Photoelectric conversion means, 21 ... ... Filter switcher, 21A ... Rotating mechanism, 25 ... CPU, 27 ... Display means, 35 ... Input means, 36 ... Control means.

Claims (2)

In the verification method of the dispensing instrument that aspirates the sample liquid and separates the dispensing liquid of the predetermined dispensing volume,
Receiving the transmitted light is transmitted through the white light source light absorbance detection container in a state where the reference solution was placed only known liquid volume containing a first dye component having a first absorbance characteristics of absorption of light of a wavelength of standards Obtaining a first absorbance detection output from the photoelectric conversion means ,
A detection liquid containing a second dye component having a second absorbance characteristic that is sucked as the dispensing liquid by the dispensing device and absorbs light having a wavelength different from the reference wavelength is injected into the absorbance detection container. Te in the state mixture was Tsu created, injecting the detection solution with the detection light filter for transmitting transmits light components the transmitted light the absorbance detection cell of a wavelength different from that of the reference of the above white light source light The second absorbance detection output is obtained from the photoelectric conversion means by transmitting the mixed liquid,
A ratio between the first absorbance detection output and the second absorbance detection output is obtained by a test value calculation means, and the ratio between the known liquid amount of the reference solution and the first and second absorbance detection outputs. Based on the above, the liquid volume of the detection liquid is calculated as a test value for the dispensing volume, so that the absorbance of the mixed liquid is detected after the detection liquid is injected from the dispensing device into the absorbance detection container. by utilizing the fact that the first and second color component is not reduced by evaporation phenomena until, assay method of the dispensing instrument and obtains the test value of the dispensing amount of the dispensing device . In the verification device of the dispensing instrument that aspirates the sample liquid and separates the dispensing liquid of the predetermined dispensing volume,
Light source means for emitting white light source light;
In a state where the reference solution containing containing a first dye component having a first absorbance characteristics of absorption of light of a wavelength of standards, the wavelength of the aspirated and the reference as the dispensing liquid by the dispensing device and the absorbance detection container to make a second absorbance detection solution containing a second pigment component having a characteristic by entering Note mixture absorbs light of different wavelengths,
White light source light emitted from the light source means is transmitted through the absorbance detection container in a state where the reference liquid is contained in the absorbance detection container, and then the liquid mixture is formed in the absorbance detection container from the light source means. Filter means for transmitting the emitted white light source light to the absorbance detection container through a detection light filter that transmits a light component having a wavelength different from the reference wavelength;
In the state in which the light transmitted through the absorbance detection container is received, the first absorbance detection output is obtained in the state where the reference liquid is contained in the absorbance detection container, and the mixed solution is contained in the absorbance detection container. Photoelectric conversion means for obtaining a second absorbance detection output;
By calculating the liquid volume of the detection liquid as the assay value of the dispensed volume based on the known liquid volume of the reference liquid and the ratio of the first absorbance detection output and the second absorbance detection output , by utilizing the fact that the first and second color component is not reduced by evaporation phenomenon during the period from the injection of the detection liquid in the photometric detection container from the dispensing device to the detection of the absorbance of the mixed solution And a test value calculation means for obtaining a test value of the dispensed amount of the dispenser.

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