Gas preparation device for odor evaluation

Abstract

The present invention comprises: a gas chromatograph 1 having a separation column 10 for separating a plurality of components contained in a gas to be analyzed; a timing detection unit 2 for detecting a timing at which each of the plurality of components exits the separation column; a gas recovery unit 5 for recovering, to a sample bag, a component gas containing all or a portion of the plurality of components exiting the separation column; a gas introduction unit 56 for introducing a dilution gas into the sample bag under a prescribed gas introduction condition; a flow rate information acquisition unit 14 for acquiring flow rate information of the component gas; a time range setting unit 63, 65, 66 for setting, upon referring to the timing, a time range in which the gas recovery unit recovers the component gas; a total volume setting unit 63, 65, 66 for setting the total volume of the component gas recovered in the sample bag and the dilution gas introduced into the sample bag; and a condition determination unit 62 for determining the gas introduction condition on the basis of the flow rate information, the time range, and the total volume.

Description

Odor evaluation gas preparation device

[0001] The present invention relates to an odor evaluation gas preparation device used to evaluate the odors (odors, fragrances) of various substances.

[0002] Fragrances added to foods, beverages, cosmetics, detergents, etc. are often created to imitate the scents (natural fragrances) emitted by natural products such as flowers, herbs, and fruits. Many natural fragrances are complex odors that are a mixture of various components, resulting in a wide variety of odors depending on the type of component and the proportion of each component. However, not all of the components that make up a natural fragrance contribute to the formation of that odor; some components contribute very little or not at all. In the field of fragrance development, there is a desire to identify the components contained in natural fragrances that contribute to odor formation and those that do not contribute to odor formation.

[0003] One method for identifying whether a component contained in a natural fragrance contributes to odor formation is the omission test. In the omission test, an omission gas is prepared by removing a component from a gas to be analyzed, and the odors of the omission gas and the gas to be analyzed are compared to evaluate whether the removed component contributes to odor formation based on the similarity of their odors.

[0004] For example, the odor evaluation device described in Patent Document 1 can be used to efficiently perform the above-mentioned omission test. The odor evaluation device described in Patent Document 1 includes a gas chromatograph having a separation column for separating the target gas, a gas collection unit that passes the target gas through the separation column multiple times and collects into separate sample bags a gas containing all components (a total component gas) and a gas excluding predetermined components (a omission gas) from the components that exit the separation column, respectively, an odor sniffing port for smelling the gas collected in each sample bag and performing a sensory evaluation, and an odor sensor that detects the odor of the gas collected in each sample bag. Then, an index value representing the similarity between the total component gas and the omission gas is calculated based on the results of the sensory evaluation or the detection results of the odor sensor.

[0005] In the odor evaluation device described above, in order to prevent highly adsorbable components contained in the target gas from adhering to the flow path from the separation column to the gas recovery unit, a dilution gas is introduced into the flow path at a constant flow rate (pressure) while the separation column and the gas recovery unit are in communication with each other. As a result, while the gas containing the components emerging from the separation column passes through the flow path, the dilution gas passes through the flow path and is recovered into the sample bag. With this configuration, the gas containing the components emerging from the separation column and an amount of dilution gas corresponding to the amount of the gas are recovered in the sample bag. The gas recovered in the sample bag is used as the odor evaluation gas for sensory evaluation or odor detection using an odor sensor.

[0006] Japanese Patent Publication No. 2022-73441

[0007] Sensory evaluation using an odor sniffing port is performed by releasing components contained in gas collected in a sample bag from the odor sniffing port and having multiple evaluators sequentially sniff the gas. Therefore, for sensory evaluation, a certain amount of gas must be contained in the sample bag. However, in the above-mentioned conventional odor evaluation device, the amount of gas collected in the sample bag is determined by the amount of gas containing components coming out of the separation column (or the period during which the gas passes through the flow path), which can make sensory evaluation difficult in some cases.

[0008] The problem to be solved by the present invention is to easily prepare any amount of gas for odor evaluation.

[0009] The odor evaluation gas preparation device according to the present invention, which has been made to solve the above problems, comprises: a gas chromatograph having a separation column that separates a plurality of components contained in an odor-containing gas to be analyzed in the time direction; a timing detection unit that detects the timing at which each of the plurality of components emerges from the separation column; a gas recovery unit that passes the gas to be analyzed through the separation column and recovers into a sample bag component gases containing all or some of the plurality of components that emerge from the separation column; a gas introduction unit that introduces a dilution gas into the sample bag under predetermined gas introduction conditions; a flow rate information acquisition unit that acquires flow rate information that is information about the flow rate of the component gases emerging from the separation column; a time range setting unit that sets a time range within which the gas recovery unit will recover the component gases, with reference to the timing of each of the plurality of components detected by the timing detection unit; and a total volume setting unit that sets the total volume of the component gases recovered in the sample bag and the dilution gas introduced into the sample bag by the gas introduction unit. and a condition determination unit that determines the gas introduction conditions by the gas introduction unit based on the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit.

[0010] According to the present invention, a gas for odor evaluation of any volume can be easily prepared.

[0011] 1 is a schematic diagram of an odor evaluation gas preparation device according to an embodiment of the present invention; 2 is a diagram showing an example of a gas preparation condition setting screen displayed on a display unit; 3 is a flowchart showing a procedure for a gas preparation condition setting unit to determine conditions for introducing a dilution gas; 4 is a diagram showing an example of the relationship between the pressure and flow rate of the dilution gas introduced by a gas introduction unit;

[0012] An odor evaluation device according to an embodiment of the present invention will now be described with reference to the drawings.

[0013] 1 is a schematic diagram of the odor evaluation device according to the present embodiment. The odor evaluation device according to the present embodiment is broadly composed of a gas chromatograph unit (GC unit) 1, a mass spectrometer unit (MS unit) 2, an odor measurement unit 3, interface units 41 and 42, and a gas recovery unit 5.

[0014] The GC section 1 includes a column 10 for separating components contained in the gas to be analyzed, a column oven 11 that houses the column 10, a sample injection section 12 provided at the inlet of the column 10, a flow path switching section 13 provided at the outlet of the column 10, and a GC control section 14 that controls each of these sections.

[0015] The MS section 2 includes a vacuum vessel 20, an ion source 21 that ionizes component molecules in the gas introduced from the GC section 1 and containing the components coming out of the column 10, an ion optical system 22 that transports the generated ions, a quadrupole mass filter 23 as a mass separation section that separates ions according to their mass numbers, an ion detector 24 that detects the mass-separated ions, and an MS control section 25 that controls each of these sections.

[0016] The interface section 41 is provided between the GC section 1 and the MS section 2, and includes a heater 411 for maintaining the pipe line at a high temperature to prevent components in the gas from being trapped (adsorbed) within the flow path.

[0017] The gas collection unit 5 is provided between the GC unit 1 and the odor measurement unit 3, and includes an attachment port (port) 51 for attaching a plurality of sample bags 511 (12 sample bags 511 are shown in Figure 1), an outlet / inlet 52 for introducing gas into and escaping from the sample bag 511 attached to the attachment port 51, an autosampler 54 equipped with a first flow path switching unit 53 for switching the flow path between the outlet / inlet 52 and the attachment port 51, a second flow path switching unit 55 for switching the flow path between the outlet / inlet 52 and the odor measurement unit 3 and the GC unit 1, a gas introduction unit 56 for introducing a dilution gas into the flow path 7 between the flow path switching unit 13 and the second flow path switching unit 55 just before the second flow path switching unit 55, and a gas collection control unit 57 for controlling the first flow path switching unit 53, the second flow path switching unit 55, and the gas introduction unit 56.

[0018] The interface unit 42 is provided in the flow path 7 between the GC unit 1 and the gas recovery unit 5, and includes a heater 421 for heating the flow path 7, for example, to about 250° C. The outlet / inlet 52, the first flow path switching unit 53, and the second flow path switching unit 55 are also heated, for example, to about 250° C. by heaters (not shown). As a result, the high-temperature gas containing the components coming out of the column 10 is introduced into the gas recovery unit 5 at the same temperature, and is recovered in the sample bag 511 together with the dilution gas.

[0019] An odor sensing port (not shown) is connected to the attachment port 51 of each sample bag 511. This allows for sensory evaluation using a human sense of smell. For example, when comparing the odor of the gas collected in the sample bag 511 (a gas for odor evaluation, described below) with that of the gas to be analyzed, a triangle comparison method, which is one of the sensory evaluation methods, may be used.

[0020] The odor measuring unit 3 is composed of an inlet 31 for drawing in the gas (gas for odor evaluation, described below) collected in the sample bag 511, a dilution unit 32 for diluting the drawn-in odor evaluation gas, a concentration unit 33 for concentrating the drawn-in gas, a sensor cell 34 equipped with a plurality of odor sensors 341 (only one is shown in FIG. 1 ) with different response characteristics for measuring the odor evaluation gas containing various odor components, a pump 35 for drawing the odor evaluation gas into the sensor cell 34, an A / D conversion unit 36 ​​for converting the detection signal from the odor sensor 341 into a digital signal, a signal processing unit 37 for analyzing and processing the digitized detection signal, and an odor measurement control unit 39 for controlling the overall operation of the odor measuring unit 3. The dilution unit 32 is composed of, for example, a syringe and its drive unit, and may dilute the odor evaluation gas with the syringe and also function as a pump to push the gas into the sensor cell 34.

[0021] The odor sensor 341 is generally a metal oxide semiconductor sensor whose resistance value changes depending on the odor components, but it may also be a sensor with other detection mechanisms, such as a conductive polymer sensor or a sensor in which a gas adsorption film is formed on the surface of a quartz oscillator or a surface acoustic wave (SAW) device.

[0022] The signal processing unit 37 and the odor measurement control unit 39 are mainly configured around a personal computer 6. In addition to the above, the personal computer 6 also includes, as its functions, a data processing unit 61 for analyzing and processing the signal acquired by the ion detector 24 of the MS unit 2, a central control unit 62 for overall control of the control units 14, 25, 39, and 57, a gas preparation condition setting unit 63 for setting conditions for preparing a gas for odor evaluation, and a memory unit 64, and is connected to an input unit 65 such as a keyboard or mouse and a display unit 66. In this embodiment, when gas is collected in the sample bag 511, the GC unit 1, MS unit 2, and gas collection unit 5 operate in an integrated manner, and when the odor of the gas collected in the sample bag 511 is measured by the odor measurement unit 3, the gas collection unit 5 functions as an autosampler, and the gas collection unit 5 and the odor measurement unit 3 operate in an integrated manner. In this embodiment, the GC unit 1, MS unit 2, odor measurement unit 3, and gas collection unit 5 are each described as being controlled by a separate control unit, but it is also possible to have a common control unit control the GC unit 1 and MS unit 2, and a common control unit control the odor measurement unit 3 and gas collection unit 5.

[0023] The odor measuring unit 3 measures gas components as follows. That is, when a target gas (target gas) is introduced into the sensor cell 34, the components in the target gas come into contact with the multiple odor sensors 341, and different detection signals are output in parallel from each of the odor sensors 341. These detection signals are sampled by the A / D converter 36, digitized, and input to the signal processing unit 37. The signal processing unit 37 acquires one piece of detection data for each target gas from each odor sensor 341. Therefore, for example, if the sensor cell 34 includes ten odor sensors 341, ten pieces of detection data will be obtained by measuring a certain target gas. Because the ten odor sensors 341 each have different response characteristics, a ten-dimensional odor space can be considered, with the outputs of these ten odor sensors 341 acting as axes in different directions. The origin of this odor space is the state where the outputs of all odor sensors 341 are zero.

[0024] In the odor space, the 10 detection data can be positioned as a single measurement point. Considering an odor vector starting from the origin of the odor space and ending at the measurement point, the length of the odor vector corresponds to the "odor intensity" of the target gas (i.e., the concentration of odor components in the target gas), and the direction of the odor vector corresponds to the "odor quality." That is, if an odor vector obtained by measuring a target gas is oriented in a similar direction to an odor vector obtained by measuring another target gas, the two can be considered to be similar odors. Conversely, if the vectors' orientations are significantly different, the two can be considered to be distant odors. Therefore, the angle θ between the two vectors is used as an index for determining the similarity of the orientations of the two vectors, and the similarity of the "odor quality" can be determined based on this angle θ. For example, when two odor vectors overlap (are oriented exactly the same) (i.e., when θ = 0), the similarity rate is set to 100%, and when the angle θ is equal to or greater than a predetermined value α, the similarity rate is set to 0%. When the angle θ is in the range of 0 to α, the similarity rate is determined according to the angle θ.

[0025] Furthermore, if the output level of the odor sensor 341 is approximately linear with respect to the target gas concentration (concentration of odor components), the direction of the odor vector will be constant regardless of the concentration if the odor is the same. Therefore, the angle θ between the two odor vectors will also be constant regardless of the concentration, making it possible to accurately distinguish differences in odor quality between multiple target gases.

[0026] On the other hand, if the output of the odor sensor 341 is nonlinear with respect to the concentration of odor components, the direction of the odor vector changes depending on the concentration, even for the same type of odor, making it difficult to accurately distinguish differences in odor quality among multiple target gases. In such cases, during target gas measurement, feedback control of the dilution unit 32 and the concentration unit 33 based on the output values ​​of each odor sensor 341 can be performed to adjust the target gas concentration introduced into the sensor cell 34 to always be appropriate. Specifically, the detection signal obtained from the odor sensor 341 is positioned as a measurement point in the above-mentioned odor space, and an odor vector is created with the origin as its start point and the measurement point as its end point, and the length of the vector is calculated. The dilution ratio in the dilution unit 32 or the concentration ratio in the concentration unit 33 is then controlled so that the length becomes a predetermined value.

[0027] <Basic Operation of the Odor Evaluation Device> Next, the basic operation of the odor evaluation device of this embodiment will be described. When an instruction to execute various operations using the odor evaluation device is given through the input unit 65, under the control of the central control unit 62, the GC control unit 14, MS control unit 25, odor measurement control unit 39, and gas collection control unit 57 control the GC unit 1, MS unit 2, odor measurement unit 3, and gas collection unit 5, respectively.

[0028] When a target gas for analysis extracted from an odorous gas, liquid, or solid sample is introduced into the column 10 in a gaseous or liquid state through the sample injection unit 12, the gas is introduced into the column 10 through the sample introduction unit 121. When the target gas for analysis is introduced into the column 10 in a liquid state, the target gas is vaporized in the sample introduction unit 121 and then pushed by the carrier gas and introduced into the column 10 through the sample introduction unit 121. The components contained in the target gas for analysis are separated while passing through the column 10 and emerge from the column 10 with a time lag. The components emerging from the column 10 pass through the flow path switching unit 13 and are then introduced into the MS unit 2 through the interface unit 41, or into the gas recovery unit 5 through the interface unit 42. The GC control unit 14 acquires information such as the pressure at the carrier gas inlet (sample injection unit 12), the pressure at the carrier gas flow path switching unit 13, the column dimensions (length, inner diameter), and the temperature of the column oven 11, and calculates and stores the flow rate of the carrier gas containing the components (hereinafter referred to as component gas) coming out of the column 10 based on the information. That is, in this embodiment, the GC control unit 14 corresponds to the flow rate information acquisition unit of the present invention.

[0029] When examining the timing at which each component contained in the gas to be analyzed emerges from the column 10, all of the components emerging from the column 10 are introduced into the MS section 2. Therefore, in this case, from the start of introduction of the gas to be analyzed into the column 10 until all of the components emerge from the column 10, the flow path switching section 13 is kept in a state in which the GC section 1 and the MS section 2 are in communication with each other. As a result, the components emerging from the column 10 are introduced into the MS section 2 sequentially.

[0030] The components introduced into the MS section 2 are ionized in the ion source 21 under the control of the MS control section 25, and only ions having specific mass numbers selected by the quadrupole mass filter 23 reach the ion detector 24. The quadrupole mass filter 23 then repeatedly performs mass scanning over a predetermined mass range, and the ion detector 24 obtains a detection signal that forms the basis of a mass spectrum for each scan.

[0031] The detection signal obtained by the ion detector 24 is processed by the data processing unit 61 to repeatedly generate mass spectra with the mass number on the horizontal axis and the signal intensity on the vertical axis. A total ion chromatogram (TIC) is also generated by setting the time on the horizontal axis and the signal intensity on the vertical axis without focusing on the mass number. Furthermore, a mass chromatogram is generated by setting the time on the horizontal axis and the signal intensity on the vertical axis while focusing on a specific mass number. While the generation of a TIC is sufficient to detect the timing at which each component emerges from the column 10, a mass spectrum or mass chromatogram may also be generated as needed. The TIC data generated by the data processing unit 61 is stored in the data processing unit 61. The data processing unit 61 also extracts peaks from the generated TIC and stores information about the peaks (e.g., peak intensity, peak area, peak width (time range)). In this embodiment, the MS unit 2 corresponds to the timing detection unit of the present invention. Note that "timing" here refers to the time range during which a certain component is detected by the MS unit 2.

[0032] When preparing a gas for evaluating the odors of components contained in the target gas (hereinafter referred to as odor evaluation gas), all or a portion of the components exiting the column 10 are introduced into the gas collection unit 5. That is, under the control of the GC control unit 14 and the gas collection control unit 57, the drive motor of the flow path switching unit 13, the first flow path switching unit 53, and the second flow path switching unit 55 are controlled to switch between a state in which the GC unit 1 and the MS unit 2 are connected and a state in which the GC unit 1 and the gas collection unit 5 are connected. Furthermore, when the GC unit 1 and the gas collection unit 5 are connected, a dilution gas is flowed from the gas inlet 56 into the flow path 7 between the flow path switching unit 13 and the second flow path switching unit 55. As a result, the component gases exiting the column 10 are collected together with the dilution gas into the sample bag 511, and the odor evaluation gas is prepared. As the dilution gas, an odorless or nearly odorless gas that does not affect the odors of the components introduced into the gas collection unit 5, such as nitrogen or helium, is used.

[0033] In this example, the user sets some of the conditions for preparing the gas for odor evaluation. The gas preparation condition setting unit 63 displays a gas preparation condition setting screen on the display unit 66 for the user to set the conditions, and accepts input from the user via the input unit 65. Figure 2 shows an example of the gas preparation condition setting screen 661. It is assumed that the timing at which each component contained in the target gas emerges from the column 10 has been investigated before the user sets the conditions.

[0034] 2, the gas preparation condition setting screen 661 has arranged thereon a TIC 662 created by the data processing unit 61 and a table 663 displaying the introduction destination of the components emerging from the column 10. The table 663 also has arranged thereon a gas collection time range display area 6631, a gas introduction destination display area 6632, and an input field 6633 for setting the position of the sample bag 511 into which the odor evaluation gas is introduced.

[0035] On the gas preparation condition setting screen 661, the user first sets the gas collection time range for collecting the components (component gases) coming out of the column 10 into the sample bag 511. The gas collection time range is set, for example, by the user operating the mouse to specify an arbitrary time range on the TIC 662 with the cursor. Alternatively, the data processing unit 61 may automatically divide the entire time range of the TIC 662 into multiple parts, and the user may set each divided time range by operating the mouse or the like on the TIC 662 to select it.

[0036] When a gas collection time range is set in TIC 662, its start and end dates are displayed in a gas collection time range display area 6631 of table 663, and the letters "FAS" indicating that the component gases coming out of column 10 will be introduced into the gas collection unit 5 are displayed in a gas introduction destination display area 6632. At this time, the start and end dates of the remaining time ranges outside the set gas collection time range within the entire time range of TIC 662 are also displayed in the gas collection time range display area 6631, and the letters "MS" indicating that the components coming out of column 10 will be introduced (omitted) into the MS unit 2 are displayed in the gas introduction destination display area 6632 corresponding to the remaining time ranges. When multiple time ranges for collecting the components coming out of column 10 are set in TIC 652, each time a new time range is set, the start and end dates of the time range are displayed in the gas collection time range display area 6631, and the start and end dates of the remaining time ranges are rewritten.

[0037] Next, the user sets the position of the sample bag 511 from which the component gases are collected. The position of the sample bag 511 is set, for example, by using a keyboard to input the number assigned to the attachment port 51 to which the sample bag 511 is connected into the input field 6633 of the table 663.

[0038] Once the position of the sample bag 511 has been set, the gas preparation condition setting unit 63 displays a table 664 on the gas preparation condition setting screen 661, which has an input field 6641 for setting the volume of the gas (component gas and dilution gas) to be introduced into the sample bag. The user sets the total volume (volume of odor evaluation gas) of the component gas and dilution gas to be introduced into the sample bag by, for example, using a keyboard to input a desired volume into the input field 6641. The volume of the odor evaluation gas is preferably set to approximately 0.5 L to 10 L so that one or more people can perform performance evaluation of the odor evaluation gas.

[0039] The contents set as described above (the gas collection time range for collecting the component gases coming out of the column 10, the position of the sample bag 511 where the component gases are collected, and the volume of the odor evaluation gas introduced into the sample bag 511) are stored in the gas preparation condition setting unit 63. In this embodiment, the display unit 66 (gas preparation condition setting screen 661), the input unit 65, and the gas preparation condition setting unit 63 function as the time range setting unit and the total volume setting unit of the present invention.

[0040] The gas preparation condition setting unit 63 further determines the conditions under which the gas introduction unit 56 introduces the dilution gas into the sample bag 511 from the contents set on the gas preparation condition setting screen 661. Figure 3 is a flowchart showing the procedure by which the gas preparation condition setting unit 63 determines the conditions under which the dilution gas is introduced.

[0041] First, the gas preparation condition setting unit 63 reads and acquires from the GC control unit 14 the flow rate of the component gases introduced from the column 10 into the gas recovery unit 5 within the set gas recovery time range (step S101). The gas preparation condition setting unit 63 also calculates the time during which the GC unit 1 and the gas recovery unit 5 are in communication with each other from the set gas recovery time range (step S102). Note that step S101 may be performed after step S102.

[0042] Next, the gas preparation condition setting unit 63 calculates the volume of the component gas collected in the sample bag 511 from the flow rate of the component gas acquired in step S101 and the time calculated in step S102 (step S103). Then, the volume of the dilution gas to be introduced into the sample bag 511 is calculated by subtracting the volume of the component gas from the set volume of the odor evaluation gas (step S104). The flow rate of the dilution gas to be introduced into the sample bag 511 is calculated by dividing the volume by the time calculated in step S102 (step S105).

[0043] In this embodiment, the dilution gas flowing from the gas inlet 56 is introduced into the sample bag 511 through the flow path 7 together with the component gas flowing from the column 10. Therefore, the flow rate of the dilution gas flowing from the gas inlet 56 varies depending on the flow rate of the component gas flowing from the column 10 and the pressure at which the gas inlet 56 introduces the dilution gas. Therefore, the relationship between the pressure and flow rate of the dilution gas under certain component gas flow conditions is determined in advance, and a relational expression showing this relationship is pre-stored in the memory 64 of the computer 6. FIG. 4 is an example of a graph showing the relationship between the pressure and flow rate of the dilution gas. The gas preparation condition setting unit 63 reads the relational expression between the pressure and flow rate of the dilution gas from the memory 64 and calculates the pressure at which the gas inlet 56 introduces the dilution gas by substituting the flow rate of the dilution gas calculated in step S105 (step S106).

[0044] As a result of the above, the pressure at which the gas introduction unit 56 introduces the dilution gas is determined. The gas preparation condition setting unit 63 displays the determined pressure in a table 664. The gas preparation condition setting unit 63 also creates a method file that describes the settings made by the user on the gas preparation condition setting screen 661 and the pressure at which the dilution gas is introduced determined from those settings, and stores the method file in the storage unit 64. The central control unit 62 performs overall control of the GC control unit 14, the MS control unit 25, and the gas recovery control unit 57 based on the created method file.

[0045] 2 illustrates a state in which the components exiting the column 10 during time ranges T2 and T6 shown in TIC 662 are collected in the sample bag 511 connected to port 2, and the components exiting the column 10 during time range T4 are collected in the sample bag 511 connected to port 3. The components exiting the column 10 during the two time ranges are collected in the sample bag 511 connected to port 2. In this case, when the user first sets time range T2 on the gas preparation condition setting screen 661, the gas preparation condition setting unit 63 calculates the pressure when introducing the dilution gas in steps S101 to S106, assuming that the components (component gases) exiting the column during time range T2 are collected in the sample bag 511. When the user then sets time range T6, the gas preparation condition setting unit 63 again performs the processes of steps S101 to S106. At this time, the gas preparation condition setting unit 63 calculates the volume of the dilution gas to be introduced into the sample bag in step S104, taking into account the volume of the component gases collected in the sample bag 511 during time range T2. That is, the volume of the dilution gas to be introduced into the sample bag 511 is calculated by subtracting the volume of the component gas collected in the sample bag 511 in the time range T2 and the volume of the component gas collected in the sample bag 511 in the time range T6 from the set volume of the odor evaluation gas. In this way, the pressure when the dilution gas is introduced is updated. In this embodiment, the gas preparation condition setting unit 63 not only functions as part of the time range setting unit and total volume setting unit of the present invention, but also functions as the condition determination unit of the present invention.

[0046] Since the dilution gas has the effect of cleaning the flow path in the gas recovery unit 5, it is preferable that the gas inlet unit 56 be configured to allow the dilution gas to flow through the flow path 7 whether or not the component gas from the GC unit 1 is flowing through the flow path 7. However, the dilution gas may be configured to flow through the flow path 7 only when the component gas from the GC unit 1 is flowing through the flow path 7, or the dilution gas may not be allowed to flow even when the component gas coming out of the column 10 is introduced into the gas recovery unit 5.

[0047] If the dilution gas is not flowed when the component gas is introduced into the gas recovery unit 5, the gas introduction unit 56 may flow the dilution gas through the flow path 7 after the component gas is collected in the sample bag 511, and introduce the dilution gas into the sample bag 511. In this case, the introduction time for introducing the dilution gas into the sample bag 511 can be set independently of the time for collecting the component gas in the sample bag 511. Alternatively, the gas preparation condition setting unit 63 may determine this introduction time. For example, when the user sets the pressure at which the gas introduction unit 56 introduces the dilution gas on the gas preparation condition setting screen 661, the gas preparation condition setting unit 63 calculates the flow rate of the dilution gas from the relationship between the pressure and flow rate of the dilution gas. The gas preparation condition setting unit 63 also calculates the volume of the dilution gas to be introduced into the sample bag 511 in the same manner as in steps S101 to S104. The introduction time for introducing the dilution gas is then calculated by dividing the volume of the dilution gas by the flow rate of the dilution gas. Similarly, when the user sets the introduction time for the gas introduction unit 56 to introduce the dilution gas, the gas preparation condition setting unit 63 may determine the pressure at which the gas introduction unit 56 introduces the dilution gas from the volume of the dilution gas to be introduced into the sample bag and the relationship between the flow rate and pressure of the dilution gas.

[0048] Alternatively, the dilution gas may be introduced directly into the autosampler 54 from the gas inlet 56 without passing through the flow path 7. In this case, the GC control unit 14 (flow rate information acquisition unit) acquires information on the pressure at the carrier gas inlet (sample inlet 12) and flow path switching unit 13, the dimensions (length, inner diameter) of the column 10, the temperature of the column oven 11, and the like, as well as information on the pressure of the component gas at the second flow path switching unit 55, and calculates and stores the flow rate of the component gas introduced into the autosampler 54 based on this information. The dilution gas may be introduced into the autosampler 54 from the gas inlet 56 when the GC unit 1 and the gas recovery unit 5 are in communication with each other, or may be introduced after the component gas is recovered in the sample bag 511. When the dilution gas is introduced when the GC unit 1 and the gas recovery unit 5 are in communication with each other, the conditions for introducing the dilution gas can be determined in the same manner as in the flowchart shown in FIG. 3. When a dilution gas is introduced after the component gas is collected in the sample bag 511, the conditions for introducing the dilution gas can be determined in the same manner as in the procedure described in paragraph 0046.

[0049] As described above, by introducing the gas to be analyzed into the column 10, the gas for odor evaluation containing all or part of the components coming out of the column 10 is collected in a predetermined volume in a predetermined sample bag 511.

[0050] The odor evaluation gas collected in the sample bag 511 is subjected to measurement or sensory evaluation by the odor measurement unit 3. When the odor evaluation gas is subjected to measurement by the odor measurement unit 3, the flow paths of the first and second flow path switching units 53, 55 are switched under the control of the gas collection control unit 57, and the odor evaluation gas is sequentially drawn from the sample bag 511 into the sensor cell 34 by the pump 35 under the control of the odor measurement control unit 39. As a result, components contained in the odor evaluation gas come into contact with each of the multiple odor sensors 341, which then output a detection signal.

[0051] Furthermore, when the odor evaluation gas is used for sensory evaluation, multiple odor evaluators sniff the odors from multiple odor sniffing ports (not shown) connected to the attachment ports 51 of each sample bag 511. It is also possible to first collect the gas in the sample bag 511 and then perform the sensory evaluation. The volume of the odor evaluation gas can be appropriately set according to the capacity of the sample bag 511, making it possible to prepare an amount of odor evaluation gas appropriate for the sensory evaluation. Furthermore, it is possible to prevent gas from being introduced into the sample bag 511 in excess of its capacity.

[0052] (Modifications) The present invention is not limited to the above-described embodiment, and can be modified as appropriate.

[0053] For example, in the above embodiment, the operator uses a keyboard or the like to input the volume of the odor evaluation gas to be collected in the sample bag 511 into the gas preparation condition setting screen 661, but the volume of the odor evaluation gas may be pre-stored in the memory unit 64 in association with the type of sample bag 511, and the volume of the odor evaluation gas may be set by selecting the type of sample bag 511 that will collect the odor evaluation gas.

[0054] In the above embodiment, the gas to be analyzed is passed through the column 10 once, and components emerging from the column 10 within any non-overlapping time ranges are collected in different sample bags 511. However, for example, the gas to be analyzed may be passed through the column 10 multiple times, and components emerging from the column 10 within the same time range may be collected in different sample bags 511. In this case, by varying the volume of the gas for odor evaluation collected in each sample bag 511, multiple gases for odor evaluation with different concentrations of a certain component can be prepared.

[0055] Aspects It will be apparent to those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0056] (Item 1) An apparatus for preparing a gas for odor evaluation according to one aspect of the present invention comprises: a gas chromatograph having a separation column that separates a plurality of components contained in an odor-containing gas to be analyzed in a time direction; a timing detection unit that detects the timing at which each of the plurality of components emerges from the separation column; a gas recovery unit that passes the gas to be analyzed through the separation column and recovers into a sample bag a component gas containing all or part of the plurality of components that emerges from the separation column; a gas introduction unit that introduces a dilution gas into the sample bag under predetermined gas introduction conditions; a flow rate information acquisition unit that acquires flow rate information that is information about the flow rate of the component gases emerging from the separation column; a time range setting unit that sets a time range for the gas recovery unit to recover the component gases by referring to the timing of each of the plurality of components detected by the timing detection unit; and a total volume setting unit that sets the total volume of the component gases recovered in the sample bag and the dilution gas introduced into the sample bag by the gas introduction unit. and a condition determination unit that determines the gas introduction conditions by the gas introduction unit based on the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit.

[0057] According to the odor evaluation gas preparation device of paragraph 1, once the time range for collecting the component gas and the total volume of the component gas and dilution gas collected in the sample bag are set, the introduction conditions for introducing the dilution gas are automatically determined, making it possible to easily prepare any amount of odor evaluation gas.

[0058] (2) The odor evaluation gas preparation device according to the first paragraph may further include a memory unit storing a relational expression between the flow rate and pressure of the dilution gas introduced by the gas introduction unit, wherein the gas introduction unit introduces the dilution gas into a flow path connecting the separation column and the sample bag while the separation column and the sample bag are in communication with each other, and the condition determination unit calculates the flow rate of the dilution gas introduced by the gas introduction unit from the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit, and determines the pressure at which the gas introduction unit introduces the dilution gas based on the calculated flow rate and the relational expression.

[0059] According to the odor evaluation gas preparation device of paragraph 2, the pressure as a condition for introducing the dilution gas is automatically determined, so any amount of odor evaluation gas can be easily prepared.

[0060] (Clause 3) In the odor evaluation gas preparation device according to paragraph 1, the gas introduction unit introduces the dilution gas into the sample bag after the gas recovery unit recovers the component gas into the sample bag, and the condition determination unit can determine the volume of the dilution gas introduced by the gas introduction unit from the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit.

[0061] According to the odor evaluation gas preparation device of paragraph 3, even when the amount of odor evaluation gas is adjusted after the component gases have been collected in the sample bag, the volume of the dilution gas, which is a condition for introducing the dilution gas, is automatically determined, so any amount of odor evaluation gas can be easily prepared.

[0062] (4) In the odor evaluation gas preparation device of any one of paragraphs 1 to 3, the gas recovery unit can pass the target gas to be analyzed through the separation column multiple times, thereby recovering multiple component gases containing the same component that come out of the separation column into different sample bags, and the volume setting unit can set different total volumes for the different sample bags.

[0063] According to the apparatus for preparing a gas for odor evaluation according to the fourth aspect, it is possible to prepare a plurality of gases for odor evaluation each having a different concentration of a certain component.

[0064] 1...GC section 10...Column 12...Sample injection section 13...Flow path switching section 14...GC control section 2...MS section 25...MS control section 3...Odor measurement section 31...Inlet 34...Sensor cell 341...Odor sensor 36...A / D conversion section 37...Signal processing section 39...Odor measurement control section 41, 42...Interface section 411, 421...Heater 5...Gas recovery section 51...Attachment port 511...Sample bag 52...Outlet / outlet port 53...First flow path switching section 54...Autosampler 55...Second flow path switching section 56...Gas introduction section 57...Gas recovery control section 6...Personal computer 61...Data processing section 62...Central control section 63...Gas preparation condition setting section 64...Storage section 65...Input section 66...Display section 661...Gas preparation condition setting screen 662...TIC 663, 664...Table

Claims

a gas chromatograph having a separation column for separating a plurality of components contained in an odorous gas to be analyzed in the time direction; a timing detection unit for detecting the timing at which each of the plurality of components emerges from the separation column; a gas recovery unit for passing the gas to be analyzed through the separation column and recovering into a sample bag a component gas containing all or a portion of the plurality of components emerging from the separation column; a gas introduction unit for introducing a dilution gas into the sample bag under predetermined gas introduction conditions; a flow rate information acquisition unit for acquiring flow rate information which is information regarding the flow rate of the component gas emerging from the separation column; a time range setting unit for setting a time range during which the gas recovery unit recovers the component gas by referring to the timing of each of the plurality of components detected by the timing detection unit; a total volume setting unit for setting the total volume of the component gas recovered in the sample bag and the dilution gas introduced into the sample bag by the gas introduction unit; and a condition determination unit for determining the gas introduction conditions by the gas introduction unit based on the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit. A gas preparation device for odor evaluation comprising:

2. A gas preparation device for odor evaluation as described in claim 1, further comprising a memory unit storing a relational equation between the flow rate and pressure of the dilution gas introduced by the gas introduction unit, wherein the gas introduction unit introduces the dilution gas into a flow path connecting the separation column and the sample bag while the separation column and the sample bag are in communication with each other, and the condition determination unit calculates the flow rate of the dilution gas introduced by the gas introduction unit from the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit, and determines the pressure at which the gas introduction unit introduces the dilution gas based on the calculated flow rate and the relational equation.

3. A gas preparation device for odor evaluation as described in claim 1, wherein the gas introduction unit introduces the dilution gas into the sample bag after the gas recovery unit has recovered the component gases in the sample bag, and the condition determination unit determines the volume of the dilution gas introduced by the gas introduction unit from the flow rate information acquired by the flow rate information acquisition unit, the time range set by the time range setting unit, and the total volume set by the total volume setting unit.

4. A gas preparation device for odor evaluation as described in any one of claims 1, wherein the gas recovery unit passes the gas to be analyzed through the separation column multiple times, thereby recovering multiple component gases containing the same component coming out of the separation column into different sample bags, and the volume setting unit sets different total volumes for each of the different sample bags.

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