JP7070758B2 - Smell device - Google Patents

Description

The present invention relates to an odor device such as an odor gas chromatography (GC) or an odor gas chromatography mass spectrometer (GCMS) that analyzes an odor.

The odor device is a hydrogen flame ionization detector (FID) after the sample gas is introduced into the separation column by the carrier gas supplied from the carrier gas bomb through the sample introduction part such as the sample vaporization chamber, and the components are separated by the separation column. ) And a mass analyzer (MS), which is a key aroma component for foods, etc. It is used in a wide range of applications such as identification of gas and analysis of offensive odors from materials and environment.

When analyzing odors with an odor sniffer, substances that are not normally felt by the human sense of smell are also detected, so it is necessary to determine whether or not the actually separated component gas is odorous by the human sense of smell. be.
For this reason, the component gas branched in the previous stage that is guided to the detector is introduced by a transfer line (heating conduit) to the smelling port where humans smell, and the human actually smells from the retention time and the signal of the detector. It is identified as a gas (substance) that is perceived by the human sense of smell.

Normally, odor analysis by an odor device is performed by an analyst who operates the odor device and an evaluator who performs sensory evaluation by sniffing the odor at the odor port.
Sensory evaluation needs to be considered so that the evaluation can be concentrated in an environment without disturbing odors. Therefore, the height and arrangement of the odor port are considered so that sensory evaluation can be performed in a comfortable posture, and the transfer line length from the branch element inside the column oven to the odor port outside the column oven is a certain length. (At least around 1 m) is required.
In addition, since the temperature of the column oven is about 40 ° C to 200 ° C in the separation analysis of the sniffing device, the heating conduit of the transfer line is set to about 200 ° C by the heating heater, and the components separated by the separation column. The gas is prevented from being adsorbed or condensed in the heating conduit of the transfer line (see, for example, Non-Patent Document 1).

Koji Kita and Reiko Yamashita (2013) "Smell Analysis Comprehensive System Part 1 Smell Gas Chromatograph Mass Spectrometer" ("Technical Sheet" published on September 10, 2013, No. 13007, Osaka Research Institute of Industrial Science and Technology)

In separation analysis by sniffing gas chromatography (GC) or sniffing gas chromatography mass spectrometer (GCMS), the temperature of the column oven (separation column) rises at a rate of 10 ° C./min, for example, in the range of 40 ° C. to 200 ° C. On the other hand, the transfer line (heating conduit) between the branch element in the column oven and the sniffing port outside the column oven is fixed at a constant temperature of about 200 ° C by a heating heater, but the column oven If the temperature and the transfer line temperature are different, some inconveniences may occur as follows.

(1) In the relatively low temperature range of the temperature rise program, the component gas eluted from the separation column may be thermally decomposed and altered by the transfer line at a high temperature.
(2) In the case of low temperature and high temperature of the column oven, the relative gas flow rate resistance of the component gas of the transfer line changes, the branch flow rate ratio in the branch element fluctuates, and the flow rate to the detector changes, and in the detector. Sensitivity conversion becomes impossible.
(3) Since the branch flow rate ratio in the branch element changes depending on the column oven temperature, the linear velocity of the component gas also changes, and the arrival time of the component gas to the detector and the sniffing port is different. Even if it is adjusted at a certain temperature in advance, it is inevitable that it will shift at another temperature.
An object of the present invention is to provide an odor device that solves the inconvenience caused by the discrepancy between the temperature of the column oven and the temperature of the transfer line.

In order to solve the above problems, the odor device of the present invention according to claim 1 has a detector and an odor port arranged outside the column oven for the component gas separated by the separation column arranged in the column oven. It is an odor device having a branch element that branches to, and the branch element and the odor port are connected by a transfer line consisting of a heating conduit covered with a heating heater. The transfer line is equipped with a heating conduit temperature control means. At the same time, a temperature sensor is arranged in the column oven so that the temperature of the column oven and the temperature of the transfer line are synchronized via the heating conduit temperature control means based on the temperature detection signal from the temperature sensor. When synchronizing the column oven temperature and the transfer line temperature, the transfer line temperature can be synchronized by giving an offset to the column oven temperature in order to fine-tune the branch flow ratio and time lag in a wide temperature range. ..

The sniffing device of the present invention according to claim 2 is the sniffing device according to claim 1, wherein a temperature sensor is arranged near the transfer line, and a temperature detection signal from the temperature sensor in the column oven and transfer are performed. Based on the temperature detection signal from the temperature sensor arranged near the line, the power supply to the heating heater of the heating conduit of the transfer line is controlled via the heating conduit temperature control means.

According to the odorizing device of the present invention, there is no possibility that the component gas separated by the separation column is altered by thermal decomposition at the transfer line, and the odor component can be accurately sniffed even in the case of temperature rise analysis.
In addition, the component gas flow rate resistance flowing through the relative transfer line changes depending on the low temperature and high temperature of the column oven, and the branch flow rate ratio in the branch element does not change and the flow rate to the detector does not change. , It is possible to perform sensitivity conversion with a detector with high accuracy.
Furthermore, since there is no discrepancy between the arrival time of the component gas to the detector and the sniffing port, the retention time and the detector signal are used as the gas (substance) that humans actually smell and feel with the human sense of smell. It can be identified consistently.
That is, the temperature of the transfer line (heating conduit) is optimally controlled without bothering the operation of the analysis engineer even if the analysis conditions (for example, the temperature rise program) are changed, so that it is possible to perform odor analysis with high accuracy. can.

It is a figure which shows the basic structure of the smelling apparatus of this invention. It is a figure which shows the detailed structure of the transfer line in the sniffing apparatus of this invention.

Hereinafter, the odor device of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a basic configuration of the sniffing device of the present invention. In this odor gas chromatography (GC) 1, the carrier gas supplied from the carrier gas cylinder (not shown) flows to the separation column 3 arranged in the column oven 10 via the sample introduction unit 2 such as the sample vaporization chamber. .. The carrier gas exits the separation column 3, passes through the main flow path 4, and is introduced into a detector 5, such as a mass spectrometer.
An odor port 8 is provided at the end of the capillary sub-flow path 7 branched from the main flow path 4 by the four-way branch element 6 provided at the outlet of the separation column 3. Further, a flow path leading to the make-up gas supply unit 9 is connected to the four-way branch element 6. The make-up gas keeps the internal pressure of the four-way branch element 6 constant, and when the detector 5 is a mass spectrometer, it prevents the atmosphere from being sucked from the sniffing port 8.

The odor port 8 is a funnel-shaped device for detecting an odor component by the evaluator's own sense of smell. The person in charge of evaluation is branched by the four-way branch element 6, guided to the sniffing port 8 together with the humidified air (not shown), and smells the component gas discharged from the sniffing port 8, but the humidified air smells. Prevents the mucous membrane in the nasal cavity of the evaluator from drying out during sniffing.

The four-way branch element 6 and the sniffing port 8 are connected by a transfer line 11 composed of a heating conduit covered with a heating heater 13.
As shown in FIG. 2, the transfer line 11 (heating conduit) is composed of a capillary subchannel 7 and a protective thin tube 12 around the transfer line 11, and a heating heater 13 is wound around the protective thin tube 12. The periphery of the heater 13 is covered with a heat insulating material (not shown).
A temperature sensor 14 is attached to a part of the protective thin tube 12 in the vicinity of the capillary auxiliary flow path 7. The temperature sensor 4 is a temperature measuring body such as a thermocouple, and measures the temperature of the capillary subchannel 7.
Further, in the column oven 10, a temperature sensor 15 for measuring the temperature in the column oven 10 is arranged at an appropriate position.

The two temperature sensors 14 and 15 are connected to the heating conduit temperature control means 16 of the heating conduit constituting the transfer line 11, and power is supplied to the heating heater 13 based on the temperature detection signals from both temperature sensors 14 and 15. To control. That is, the heating conduit temperature control means 16 controls the temperature in the column oven 10 so as to synchronize the temperature of the capillary sub-flow path 7.

With such a configuration, the sample gas is injected from the sample introduction unit 2 and the analysis is started. Normally, a program in which the temperature in the column oven 10 is set in advance, for example, 40 ° C. to 200 ° C. (10 ° C./min). The temperature rises according to.
Based on the temperature detection signals of the temperature sensor 15 in the column oven 10 and the temperature sensor 14 arranged close to the capillary sub-flow path 7 in response to the rise in temperature in the column oven 10, the heating conduit temperature control means 16 is used. The power supply to the heating heater 13 is adjusted so that the temperature of the heating conduit (transfer line) is synchronized with the temperature inside the column oven 10. In this case, the temperature rise rate of the heating conduit is required so that the temperature of the heating conduit can be raised according to the temperature in the column oven 10 by the heating conduit temperature control means 16. Practically, it is desirable to be able to handle 1 ° C to 40 ° C / min.

The temperature of the transfer line 11 may be offset with respect to the temperature in the column oven 10. By doing so, it is possible to finely adjust the branch flow rate ratio and the time lag in the four-way branch element 6 which fluctuates according to the temperature in the column oven 10 in a wide temperature range.
Reference numeral 17 is an outer wall of the column oven.

1 ・ ・ ・ Smell device 2 ・ ・ ・ Sample introduction part 3 ・ ・ ・ Separation column 4 ・ ・ ・ Main flow path 5 ・ ・ ・ Detector 6 ・ ・ ・ Four-way branch element 7 ・ ・ ・ Capillary sub-flow path 8 ・ ・・ Smell port 9 ・ ・ ・ Makeup gas supply part 10 ・ ・ ・ Column oven 11 ・ ・ ・ Transfer line (heating conduit)
12 ・ ・ ・ Protective thin tube 13 ・ ・ ・ Heating heaters 14, 15 ・ ・ ・ Temperature sensor 16 ・ ・ ・ Heating conduit temperature control means

Claims (2)

It has a branch element that branches the component gas separated by the separation column placed in the column oven to the detector and the odor port placed outside the column oven, and the branch element and the odor port are covered with a heater. In an odor device connected by a transfer line consisting of a heated conduit, the transfer line is provided with a heating conduit temperature control means, and a temperature sensor is arranged in the column oven to be used as a temperature detection signal from the temperature sensor. Based on the above, an odor device characterized in that the temperature of the column oven and the temperature of the transfer line are synchronized via the heating conduit temperature control means. In the sniffing device according to claim 1, a temperature sensor is arranged near the transfer line, and a temperature detection signal from the temperature sensor in the column oven and a temperature detection signal from the temperature sensor arranged near the transfer line. Based on the above, the sniffing device is characterized in that the power supply to the heating heater of the heating conduit of the transfer line is controlled via the heating conduit temperature control means.

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