JP2001013119A - Measurement of odor material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement result excellently correlated to an evaluation result of a sensory test by using glass wool as a collecting material for an odor material applied to a measurement technique using gas chromatography and mass spectrometry (GC/MS technique). SOLUTION: A glass tube is filled with glass wool inactivated with silanol for serving as a collecting material, and an environment including an odor material is introduced into the glass tube, so that the odor material is collected and adsorbed. Then, the odor material adsorbed in the collecting material is measured by a GC/MS technique. This method can be applied not only to low carbon-number aldehydes and/or fatty acids considered as principal constituents of an oily odor but also to various kinds of odor substances hardly evaluated by a conventional method because of their low diffusion properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an odorous substance, and is particularly suitable for measuring and detecting aldehydes and fatty acids having a relatively small number of carbon atoms, and has excellent correlation with a sensory test. Related to the measurement method.

[0002]

2. Description of the Related Art It is well known that interest in odor substances in daily life is increasing day by day as living standards improve. Among them, the exhaust odor from the kitchen (oil odor)
Odors such as food and food waste odors have a low threshold value for human odor, and even a very small amount of odors are recognized as malodor. In recent years, since highly airtight houses, office buildings, factories, and the like are adjacent to each other, measures against the above-mentioned odor have been increasingly regarded as important.

[0003] Sensory tests are widely used as a means for directly grasping such odorous substances. However, in this test method, a subjective factor of a measurer is added in determining odor, so that it is difficult to make an objective determination, and the result may not be able to be treated quantitatively. For this reason, a measurement technique (hereinafter referred to as GC / M) utilizing gas chromatography and a mass spectrometer capable of quantitative analysis of odorous substances.
S method) and the sensory test described above are preferably used in combination.

In the GC / MS method, an atmosphere to be measured containing an odorous substance is brought into contact with a collecting material by a pump or the like to be adsorbed, and then the adsorbed odorous material is heated by heating the collecting material. Mainly heat diffusion. Thereafter, the diffused odorous substances are separated and developed by gas chromatography for analysis. Such a technique for measuring odorous substances plays an important role not only in the analysis of odorous substances but also in the development of filters for the purpose of deodorization.

[0005]

In the process of developing a deodorizing filter, the inventor of the present application installed a collecting material on the upstream and downstream sides of the air flow path of the filter to perform GC.
In addition to performing measurement by the / MS method, the deodorizing effect of the above-mentioned odorous substances was evaluated in combination with a sensory test. In the results of the sensory test, the odor felt before passing through the filter was not recognized after passing through the filter, and the result that the deodorizing performance was good was obtained. However, in the GC / MS method, no odor substance was identified even in the trapping material installed on the upstream side of the filter, and the result was such that the odor substance was apparently absent, resulting in inconsistency with the sensory test. Was.

As a result of studying the cause, among the conventionally known trapping materials, those having low specificity to odorous substances, for example, aldehydes and / or fatty acids having about 3 to 12 carbon atoms are used. Although it was adsorbed, it was concluded that the diffusivity at the time of heating was low and it was difficult to analyze as a diffusion gas.

In view of the above problems, the inventors of the present application have conducted intensive studies on a method of measuring an odorous substance that is consistent with the evaluation results of the sensory test, that is, a collecting material used in the GC / MS method. The present invention has been completed. Accordingly, an object of the present invention is to provide a novel technique for measuring an odorous substance having excellent correlation with the evaluation result of the sensory test.

[0008]

In order to achieve the object, according to the method for measuring an odorant according to the present invention, after the odorant is adsorbed and collected by the collector, the odorant is adsorbed by the collector. When the odor substance is diffused and measured by the GC / MS method, the gist is that the above-mentioned trapping material is glass wool.

[0009]

Hereinafter, preferred embodiments of the present invention will be described. As described above, the measuring method of the present invention resides in that a glass wool is used as a trapping material for odor substances to be provided to the GC / MS method. As the glass wool, those having a small amount of substances that become impurities at the time of thermal diffusion can be arbitrarily selected, but commercially available glass wool used for the purpose of placing a column filler for gas chromatography in a column is preferable. . Among them, those obtained by silanizing the glass surface are particularly preferable.

Further, the method of the present invention is suitable for application to odorous substances having a low threshold value in a sensory test and low diffusivity by adopting the above-mentioned constitution. Examples of such odorous substances include those having 3 to 12 carbon atoms, particularly aldehydes and fatty acids having such low carbon numbers. As an example, first, as an aldehyde having a low carbon number, pentanal (pe) is used.
ntanal: carbon number 5), hexanal (hexan)
al: carbon number 6), heptanal (heptanal:
Carbon number 7), octanal (octanal: carbon number 8), nonanal (nonanal: carbon number 9), 2-
Nonenal (2-nonenal: carbon number 9) and the like, and valeric acid (va) as a fatty acid having a low carbon number.
lericacid: carbon number 5), caproic acid (cap
roic acid: carbon number 6), enanthic acid (hep
anic acid: carbon number 7), caprylic acid (oc
tanic acid: carbon number 8), nonanoic acid (no
and nanoic acid: carbon number 9).

[0011]

Embodiments of the present invention will be described below. In this embodiment, a case will be described in which a trapping material is arranged upstream and downstream of a predetermined deodorizing filter, and the trapping material is evaluated while also performing the performance of the filter.

First, crushed coconut shell charcoal having a bulk specific gravity of 0.48 g / ml, a specific surface area of 1200 m ² / g and a particle size of 250 to 500 μm is sandwiched and fixed between two nonwoven fabrics and pleated to obtain a width. 430mm × 600mm high ×
A deodorizing filter having a depth of 30 mm was produced. Next, a dust filter having substantially no deodorizing ability is disposed upstream of the deodorizing filter, and a cooling device and a blower fan are sequentially arranged downstream of the deodorizing filter. A glass tube filled with a trapping material, and a pump connected to the glass tube and collecting and adsorbing odorous substances on the trapping material were installed on both the upstream side and the downstream side of the deodorizing filter. .

In the above-described arrangement relationship between the air conditioner and the trapping material, a test was conducted by filling the trapping material into glass tubes installed upstream and downstream of the deodorizing filter and operating the air conditioner. Note that this test was performed in an environment adjacent to a food processing factory and in which the above-mentioned oily odor and the like were likely to be generated. In this test, a commercially available glass wool inactivated by silanol (manufactured by Perkin Elmer (US), catalog number 5412-0790), which was inactivated by silanol, was used as the trapping material according to the example, and the trapping material of the comparative example was used. As the material, "Tenax GR" (supplico, USA)
Trade name: powder containing 2,6-diphenyl-p-phenylene oxide and graphite carbon as main components). This "Tenax GR" is a US NIOS
H (: National Institute for
Occupational Safety and
Health), which is recommended as having relatively low specificity for odorants.

The above-mentioned respective trapping materials are simultaneously applied by filling them in separate glass tubes arranged in parallel, and the operation of the air conditioner is performed at a surface wind speed of (1.6 m / sec), and in parallel with this, the odor is reduced. An odorous substance was collected and adsorbed by introducing an atmosphere containing the substance into the glass tube. In this case, the introduction of the odorant into the collecting material is 0.9 (liter / liter) in the embodiment.
Min) at a rate of 30 (liters) over a period of 30 minutes, and in the comparative example, at a rate of 0.5 (liters / minute), the total trapped quantity was 15 (liters).

[0015] After the completion of the adsorption and collection on the respective collecting materials, the odorous substances adsorbed on the respective collecting materials are measured by GC / MS under the following instruments and under the main conditions. Was. -Instrument GC / MS measuring instrument: QP-5050A (manufactured by Shimadzu Corporation) Column: DB-5MS (J & W Scientif, USA)
ic; column dimensions are 30 cm long x 0.32 inside diameter
mm, coating thickness 1 μm) Thermal desorption device: ATD-400 (PERKINE, USA)
Measurement conditions Oven temperature: 40 ° C. (2 minutes) to 300 ° C. (heating rate 1)
(0 ° C / min) Injection temperature: 200 ° C Detector temperature: 250 ° C Ionization method: E1 (electron impact) method Primary heating desorption conditions: 5 minutes, 250 ° C Secondary adsorption temperature (COLD TRAP): -30 ° C Secondary heating Desorption conditions: 20 minutes, 280 ° C

With respect to the measurement chart obtained by the GC / MS method and the attribution of each odorous substance, the result on the upstream side of the deodorizing filter of the collecting material according to the embodiment is shown in FIG. FIG. 2 shows the results of FIG. 2, the results of the trapping material according to the comparative example on the upstream side of the deodorizing filter, and the results of the comparative example on the downstream side of the deodorizing filter in FIG. 4, respectively. In these figures, the vertical axis indicates the amount of the odorous substance as a relative intensity (anonymous number) output from the mass spectrometer, and the horizontal axis indicates the retention time (minute).

First, when the trapping material of the embodiment is arranged on the upstream side of the deodorizing filter, as shown in FIG. 1, valeric acid represented by A and B represented by fatty acids having a low carbon number. Caproic acid, enanthic acid indicated by C, caprylic acid indicated by D, and nonanoic acid indicated by E were observed. Further, as low-carbon number aldehydes detected from the trapping material, pentanal denoted by F, hexanal denoted by G, heptanal denoted by H, octanal denoted by I, nonanal denoted by J, and 2-nonenal denoted by K were Admitted.

On the other hand, the results of measurement of the trapping material according to the example after passing through the deodorizing filter by the GC / MS method are as shown in FIG. 2-Nonenal shown shows the most significant reduction, heptanal indicated by H, caproic acid indicated by B,
Reductions of enanthic acid indicated by C, nonanal indicated by J, caprylic acid indicated by D, nonanoic acid indicated by E, and the like were also observed. From this result, in the measurement result by the trapping material according to the example,
It was evaluated that the above series of low carbon number aldehydes and / or fatty acids were deodorized and removed by the deodorizing filter.

Based on the results of the trapping material of the above embodiment, the test subject was allowed to smell the commercially available 2-nonenal with the largest quantitative change due to deodorization and to confirm the odor. It was confirmed that it was consistent with the odor.

Next, the results of evaluating the deodorizing effect of the above deodorizing filter by a sensory test will be described. The sensory test was evaluated by two general methods: a "three-point comparative odor bag method" and a "six-step odor intensity display method". In any of these methods, it is determined that the odor intensity before and after passing through the deodorizing filter is reduced, and in particular, the “three-point comparison odor bag method”
In the determination of the concentration by the above method, a result was obtained that the odorous substance was reduced to 1/10 or less by the deodorizing filter. Therefore, a high correlation between the odor measurement method by the GC / MS method using the trapping material according to the example and the sensory test was confirmed.

Comparative Example Next, GC / MS using the trapping material according to the comparative example
The measurement results of the method will be described. First, in the detection results of the odorous substances on the upstream side of the deodorizing filter shown in FIG. 3, alkanes having 6 carbon atoms (not belonging to a specific substance) represented by L, benzene represented by M, and alkanes having 7 carbon atoms represented by N ( (Not belonging to a specific substance), an alkane having 8 carbon atoms represented by P (not belonging to the specific substance), toluene represented by Q, hexamethylcyclotrisiloxane represented by R, octamethylcyclotetrasiloxane represented by S, etc. Was done. On the other hand, as shown in FIG. 4, an alkane having 6 carbon atoms (not belonging to a specific substance) represented by L, benzene represented by M, and N represented by a trapping material disposed downstream of the deodorizing filter. Alkanes having 7 carbon atoms (not belonging to a specific substance), alkanes having 8 carbon atoms (not belonging to a specific substance) represented by P, and toluene represented by Q were observed. In the measurement using the trapping materials of these comparative examples, for example, L
As a result, it was obtained that alkanes such as alkanes having 6 carbon atoms indicated by, benzene indicated by M, toluene indicated by Q increased between the upstream side and the downstream side of the deodorizing filter. However, as described in the above sensory test results, the deodorizing performance of the deodorizing filter was determined to be relatively excellent.
It can be understood that the results of each of the MS method and the sensory test are not consistent.

The embodiment using two trapping materials has been described above with reference to the performance evaluation of the deodorizing filter.
As can be understood from the above description, from the comparison between FIG. 1 and FIG. 3, a high correlation was obtained with the sensory test evaluation by using the collecting material according to the example of the present invention. still,
The invention of the present application is applicable not only to aldehydes and / or fatty acids having a low carbon number, which is a main component such as oily odor, but also to various odor substances which have been difficult to evaluate because of their low diffusivity. It is possible to apply.

[0023]

As is clear from the above description, according to the method for measuring an odorant according to the present invention, after the odorant is adsorbed and collected by the collector, the odorant is absorbed by the collector. When the odorant is diffused and measured by the GC / MS method, the trapping material is made of glass wool. With such a configuration, it is possible to measure an odorous substance having excellent correlation with a sensory test.

[Brief description of the drawings]

FIG. 1 is a characteristic curve diagram showing a measurement result of an odorous substance detected from a trapping material on an upstream side of a deodorizing filter in order to explain an embodiment of the present invention.

FIG. 2 is a characteristic curve diagram showing measurement results of odorous substances detected from a trapping material downstream of a deodorizing filter in order to explain an embodiment of the present invention.

FIG. 3 is a characteristic curve diagram showing a measurement result of an odorous substance detected from a trapping material on an upstream side of a deodorizing filter for explaining a comparative example.

FIG. 4 is a characteristic curve diagram showing a measurement result of an odorous substance detected from a trapping material on a downstream side of a deodorizing filter for explaining a comparative example.

[Explanation of symbols]

 A Peak of valeric acid B Peak of caproic acid C Peak of enanthic acid D Peak of caprylic acid E Peak of nonanoic acid F Peak of pentanal G Peak of hexanal H Peak of heptanal I Peak of octanal J Peak of nonanal K Peak of 2-nonanal Peak L Alkane (carbon number 6) peak M Benzene peak N Alkane (carbon number 7) peak P Alkane (carbon number 8) peak Q Toluene peak R Hexamethylcyclotrisiloxane peak S Octamethylcyclotetrasiloxane Peak of

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuko Seki 7-floor Kitatone, Sowa-cho, Sarushima-gun, Ibaraki Prefecture Within Japan Vilene Co., Ltd. This Vilene Co., Ltd.

Claims (3)

[Claims] After the odorous substance is adsorbed and collected by a collecting material, the odorous substance adsorbed on the collecting material is diffused to obtain a GC / GC.
A method for measuring an odorous substance, wherein the collecting material is glass wool, which is measured by the MS method. 2. The method according to claim 1, wherein the glass wool has been subjected to a silanization treatment. 3. The odorant according to claim 1, wherein the odorant is an aldehyde and / or a fatty acid having 3 to 12 carbon atoms.
Alternatively, the method for measuring an odorant according to claim 2.