JP4527603B2 - Method for detecting volatile organic compounds - Google Patents

Description

  The present invention relates to a method for detecting a volatile organic compound present on the surface of a substrate.

  The Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) is a surface analyzer that is currently developing a wide range of applications because it can detect not only elements and inorganic substances but also organic compounds. TOF-SIMS enables high-sensitivity detection of organic compounds present on the surface, but detection is low-sensitivity when the ionization efficiency of the target substance itself is low or depending on the state of the surrounding background substance. There is a case. Furthermore, TOF-SIMS is a method for measuring under high vacuum, and organic compounds with a low boiling point gradually evaporate during the measurement, making detection difficult. Therefore, in order to make effective use of TOF-SIMS, it is necessary to solve these problems and expand the range of use.

Known methods for increasing the sensitivity of TOF-SIMS to date include, for example, a method of adding an organic matrix (Non-Patent Document 1), a method of depositing a metal such as Au (Non-Patent Document 2), ESCA, and the like. And the like (non-patent document 3, patent document 1) and the like. However, these methods mainly increase the sensitivity of detection of high molecular compounds, and a method for detecting a volatile organic compound of a low molecular compound having a low boiling point with high accuracy is not known.
KJ Wu and RW Odom, Anal. Chem., 68, 5, 873-882 (1996) A. Delcorte, N. Medard and P. Bertrand, Anal. Chem., 74, 19, 4955-4968 (2002) N. Man, A. Karen, K. Takahashi, Y. Nakayama and A. Ishitani, SIMS XI, 517-520 (1998) Japanese Patent Laid-Open No. 10-132802

  It is an object of the present invention to provide a highly accurate detection method using TOF-SIMS of a volatile organic compound present on the surface of a substrate.

The gist of the present invention is as follows.
A method for detecting a volatile organic compound present on the surface of a substrate,
(1) reacting the compound with a volatile modifying reagent to make the compound non-volatile, and (2) measuring the surface of the substrate with a time-of-flight secondary ion mass spectrometer (TOF-SIMS), Detecting the compound;
Having a detection method,
About.

  According to the present invention, it is possible to detect a volatile organic compound present on the substrate surface, which has been difficult to detect in the past, with high accuracy by reflecting the initial existence state.

  The detection method of the present invention is one major point in that the volatile organic compound present on the substrate surface is modified with a volatile modifying reagent before the measurement of the substrate surface by TOF-SIMS, and the compound is made non-volatile. Has characteristics. Therefore, it is possible to detect volatile organic compounds that have been difficult to detect by TOF-SIMS measurement with high accuracy. The non-volatility of the organic compound is presumed to be due to the combination of the organic compound and the modifying reagent, resulting in a high molecular weight of the organic compound.

  The substrate is not particularly limited as long as it is made of a solid material that can be subjected to measurement by TOF-SIMS. Examples thereof include polymer plates such as PP (polypropylene) plates, fibers, paper, detergent particles, toner particles, metal plates, semiconductors, and the like, and may be plant roots, skin, teeth, hair, nails and the like. .

  The volatile organic compound to be detected is an organic compound that is volatile in the vacuum, which is the measurement condition of TOF-SIMS, and is not necessarily volatile at room temperature (20 ± 15 ° C) and normal pressure (101.3 kPa). There is no need. Such an organic compound is present on the surface of the substrate. However, the presence of the organic compound on the surface of the substrate means, for example, physical bonding such as adhesion to the substrate surface, covalent bonding with the substrate surface, and the like. Regardless of chemical bonding, embedding in the substrate surface, etc., it means that a part or all of the surface is exposed on the substrate surface.

Note that the volatility of the organic compound to be detected specifically refers to a property that can be vaporized under high vacuum (1.33 × 10 ^{−6 to} 1.33 × 10 ⁻⁷ Pa). For example, stearyl alcohol has only a vapor pressure of about 1.12 × 10 ⁻³ Pa at normal temperature and normal pressure, but in the present invention, it can be said to be a volatile organic compound and be a detection target.

  Volatile organic compounds usually have a molecular weight of approximately several tens to 400, and are not particularly limited. However, the volatile organic compounds are highly reactive with the modifying reagent and can be detected with higher accuracy. To hydroxyl group, carboxyl group, amino group, ether, ester, amide, halogen (fluorine, chlorine, bromine, iodine), nitro group, cyano group, alkyne (alkynyl group), alkene (alkenyl group), phosphate group, carbonyl It is preferably a compound having at least one functional group or structure selected from the group consisting of a group, a thiol group and a disulfide. Examples of such organic compounds include compounds having aliphatic hydroxyl groups such as stearyl alcohol, lauric acid, oleic acid, and benzyloxyethanol, aromatics such as nonylphenol and p-oxybenzoic acid ester, and phenolic hydroxyl groups. Compounds and the like. These compounds are generally those that function as surfactants, fragrances, biofunctional substances, amino acids, sugars, nucleic acids, and the like. Therefore, the detection method of the present invention is very useful for detecting those surfactants and the like on the substrate surface.

  The modifying reagent is volatile enough to evaporate under the conditions for reaction with the organic compound to be detected, and can be covalently bonded to the organic compound present on the substrate surface. Those capable of making the compound non-volatile are usually used without particular limitation. As the modifying reagent, generally, one having a molecular weight of approximately several tens to 300 is preferably used. From the viewpoint of enabling detection with higher sensitivity with TOF-SIMS, the modifying reagent is preferably a compound having a highly polar functional group, more preferably a functional group that becomes anion upon measurement with TOF-SIMS ( For example, a compound having a carboxyl group), more preferably a compound having a functional group that can be cationized (for example, an amino group, an imino group, a pyridyl group, or a pyrrolyl group). It is known that these compounds are easily ionized with proton desorption and can be detected with high sensitivity by a mass spectrometer. Therefore, considering the high reactivity with the functional group of the organic compound that is preferable as the detection target, the modifying reagent includes isocyanate group, cyanide group, acid azide group, ethylene oxide, hydroxyl group, methoxy group, amino group, and thiol group. Alkene (alkenyl group), halogen functional group, trimethylsilyl group, diazo group, carboxyl group, sulfonyl chloride group, isothiocyanate group, N-hydroxysuccinimide, carbonyl group, tosyl group, mesyl group, maleimide, disulfide, hydrazine, hydrazide And a compound having at least one group or structure selected from the group consisting of aziridine. Here, the halogen-based functional group is defined as one in which halogen is contained in a site that is eliminated from the modifying reagent when reacting with a volatile organic compound. Examples thereof include a fluoro group, a chloro group, a bromo group, an iodo group, a carbonyl chloride group, a bromoacetyl group, and an iodoacetamide group. The carboxyl group contains carboxylic anhydrides, and the carbonyl group contains aldehydes and glyoxals.

  When the organic compound has a hydroxyl group, 4- (dimethylamino) -phenylisocyanate and 2-dimethylaminoethylisocyanate are used as the modifying reagents, and when the organic compound has a carboxyl group, the modifying reagent is 4 -(Dimethylamino) -phenyl isocyanate and 1- (2-bromoethyl) pyrrole are preferably used.

  In step (1), an organic compound and a modifying reagent are reacted to make the compound non-volatile.

  The reaction between the organic compound and the modifying reagent is performed in the gas phase. For example, a base material and a modifying reagent are placed in a non-contact state in a sealed container, and left to stand for a certain time to react with each other. The reaction temperature may be equal to or higher than the temperature at which the modifying reagent volatilizes, but is preferably 10 to 60 ° C, and more preferably 20 to 40 ° C, which is close to normal temperature in consideration of the influence on the substrate. The reaction time is not particularly limited, and is usually about 1 to 30 hours although it depends on the reactivity of the organic compound and the modifying reagent. The amount ratio between the organic compound and the modifying reagent is not particularly limited, and depends on the amount of functional groups present in the organic compound and the reactivity with the modifying reagent. One mole or more may be used. In addition, when a base material contains a water | moisture content, it is preferable to fully remove the said water | moisture content before using a base material for reaction with a modification reagent.

  The reaction between the organic compound and the modifying reagent is performed under mild conditions that do not affect the presence of the organic compound on the substrate surface, and the reaction is performed in the presence of a catalyst from the viewpoint of promoting the reaction. Is preferred. As the catalyst, those having volatility to such an extent that they can be vaporized under the conditions for carrying out the reaction between the modifying reagent and the organic compound to be detected are usually used without particular limitation. What is necessary is just to select a catalyst from a well-known thing suitably according to the combination of the functional group of the organic compound of detection object, and the modification reagent to be used. For example, when the organic compound has a hydroxyl group and 4- (dimethylamino) -phenyl isocyanate or 2-dimethylaminoethyl isocyanate is used as the modifying reagent, the catalyst has a high basicity and is suitable for an electron pair of amino group. An amino compound having low steric repulsion is preferably used. For example, preferably pyridine, methyl-1,4-diazabicyclo [2.2.2] octane (Me-Dabco), triethylenediamine (TEDA) or 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU). However, TEDA or DBU is more preferable, and DBU is more preferably used. When the organic compound has a carboxyl group and 4- (dimethylamino) -phenyl isocyanate is used as the modifying reagent, 4-dimethylaminopyridine (DMAP) is used as the catalyst, and 1- (2-bromoethyl) is used as the modifying reagent. When pyrrole is used, DBU is used as the catalyst. In the reaction between the organic compound and the modifying reagent, the catalyst may be left in a closed container in a non-contact manner with them. The amount of the catalyst used depends on the type and form of the catalyst, but is generally about 0.25 to several tens of moles, preferably about 1 to several tens of moles with respect to 3 moles of the modifying reagent. For example, in the case of TEDA, Me-Daco or DBU, it is about 0.75 to 3.5 moles, preferably about 1 to 3.5 moles with respect to 3 moles of the modifying reagent. About 40 mol, and in the case of DMAP, it is about 0.5 to 1.0 mol.

  In setting reaction conditions, for example, KL Agarwal and HG Khorana, JACS, 17, 3578 (1972), Anne C. Schuemacher, RW Hoffmann, Synthesis, 2, 243-246 (2001), C. Gundu Rao, Reference may also be made to Organic Preparations and Procedures Int., 12 (3-4), 225-228 (1980).

  As a result of the above reaction, the organic compound and the modifying reagent are combined to make the compound non-volatile, that is, the organic compound loses volatility or decreases in volatility. When conducting a rigorous analysis, all organic compounds to be detected should be non-volatile, but not necessarily when examining the presence or rough distribution of organic compounds on the substrate surface. It is not necessary for all organic compounds to be nonvolatile. Whether or not the organic compound is nonvolatile can be confirmed by various methods. For example, the substrate surface is measured by TOF-SIMS before and after the reaction between the organic compound and the modifying reagent, and the molecular weight corresponding to the newly detected peak in the mass spectrum after the reaction that is not in the mass spectrum before the reaction, This can be easily done by comparing the expected molecular weight of the conjugate of the compound and the modifying reagent and confirming that they are substantially identical. Also, the surface of the base material subjected to the reaction was observed when the organic compound on the surface of the base material not subjected to the reaction disappeared by observing the surface when the base material was subjected to the reaction with the modifying reagent and when not subjected to the reaction. It can be easily performed by observing the surface with an optical microscope or the like to confirm that the organic compound is still present.

  In step (2), the surface of the substrate on which the organic compound that has been made non-volatile in step (1) is present is measured by TOF-SIMS, and the compound is detected.

  The measurement by TOF-SIMS may be performed according to a known method using a commercially available apparatus. According to the present invention, not only can the volatile organic compound present on the substrate surface be detected, but also the distribution on the substrate surface can be detected with high accuracy. In addition, it cannot be overemphasized that the detection method of this invention is used also with respect to the base material with which presence of an organic compound is anticipated.

  According to the detection method of the present invention, since it is possible to detect volatile organic compounds on the surface of a substrate that has been difficult to detect in the past, for example, the surface exuded state of an antistatic agent kneaded in a PP plate Analysis, detection of a plant vital agent adhering to the root of the plant, detection of an alcohol component or a highly volatile perfume contained in the inkjet ink, and the like.

  In the following Examples, organic compounds were detected using the following apparatus as TOF-SIMS under the following conditions.

(1) Equipment: “TOF-SIMS IV” manufactured by ION-TOF
(2) Measurement conditions:
i) High mass resolution mode
Primary ion ¹⁹⁷ Au ₁ ⁺ : 25kV (Pulsed current: 1.5pA), Cycle Time 100μs
Detection: Positive, Negative
Measurement range: 300 × 300μm ² , 128 × 128 pixel, 50s integration

ii) High spatial resolution mode Primary ion ¹⁹⁷ Au ₁ ⁺ : 25kV (Pulsed current: 0.5pA), Cycle Time 100μs
Detection: Positive, Negative
Measurement range: 100 × 100μm ² , 256 × 256 pixel, 100 scans (equivalent to 655s integration)

  In addition, charge correction using a Flood gun was performed at the time of measuring the insulator sample.

  Hereinafter, when it is referred to as vapor pressure, it indicates a value at normal temperature and normal pressure.

Example 1
Stearyl alcohol was used as a volatile organic compound having a hydroxyl group. Stearyl alcohol in 3 (w / v)% chloroform was cast on a copper plate, spin-coated, and dried (stearyl alcohol 3.33 μmol). This copper plate, modifier reagent 4- (dimethylamino) -phenyl isocyanate (vapor pressure 2.57 × 10 ⁰ Pa) 36 mg (0.222 mmol) and pyridine (vapor pressure 3.04 × 10 ³ Pa) 720 μl (9.11 mmol) ) Was allowed to stand in a sealed container, and a gas phase reaction was carried out at 50 ° C. for 4 hours. After completion of the reaction, the copper plate surface was measured by TOF-SIMS (high mass resolution mode).

  The structure of the stearyl alcohol modification reaction product is as follows.

FIG. 1 shows TOF-SIMS measurement results before and after the reaction between stearyl alcohol and the modifying reagent. When a peak near the mass number 432 of the mass spectrum corresponding to the molecular weight of the modification product of stearyl alcohol was noted, a peak was confirmed at 433. Since this is a peak that is not confirmed in the copper plate before the reaction, it was considered to be a molecular ion peak ([M + H] ⁺ structure) of the modification reaction product newly generated by the reaction with the modification reagent. Therefore, it can be seen that volatile stearyl alcohol, which has been conventionally difficult to measure with TOF-SIMS, can be detected by the above operation.

Example 2
In the same manner as in Example 1, stearyl alcohol was applied on a copper plate. The copper plate, 72 mg (0.444 mmol) of the modifying reagent 4- (dimethylamino) -phenyl isocyanate, and 75 mg (0.658 mmol) of TEDA (vapor pressure 1.64 × 10 ² Pa) were allowed to stand in a sealed container. Then, a gas phase reaction was performed at 25 ° C. overnight. After completion of the reaction, the copper plate surface was measured by TOF-SIMS (high mass resolution mode).

  FIG. 2 shows the TOF-SIMS measurement results after the reaction between stearyl alcohol and the modifying reagent. A peak was confirmed at 433 as in Example 1. Therefore, it can be seen that when TEDA is used as the catalyst, the reaction with the modifying reagent can be carried out at room temperature (25 ° C.), and stearyl alcohol can be sufficiently detected. Since the reaction with the modifying reagent is performed at room temperature, it is considered that there is substantially no influence on the presence of stearyl alcohol on the copper plate surface, and stearyl alcohol can be detected with higher accuracy than when pyridine is used. Conceivable.

  In this example, the presence of stearyl alcohol on the surface of the copper plate was measured at 25 ° C. with a CCD camera attached to TOF-SIMS over time depending on whether or not the reaction between stearyl alcohol and the modifying reagent was performed. Then, it was observed separately. The image is shown in FIG. In the case where the reaction with the modifying reagent was not carried out, it volatilized in about 45 minutes and the stearyl alcohol disappeared from the copper plate. On the other hand, in the case where the reaction was carried out, it was clearly observed even after 1 hour. It was captured that it existed. Therefore, it can be seen from this result that stearyl alcohol is non-volatile by the reaction between stearyl alcohol and the modifying reagent.

Example 3
A polypropylene (PP) plate was used as a measurement object by TOF-SIMS. In the PP plate, N, N-bis (2-hydroxyethyl) octadecylamine (DEA) as an antistatic agent and stearyl alcohol for accelerating the bleed out of DEA are kneaded. Until now, DEA distribution could be confirmed by direct measurement of TOF-SIMS, but stearyl alcohol was not detected.

In Example 2, the copper plate was replaced with a PP plate, and similarly subjected to a reaction with a modifying reagent. After the reaction was completed, the surface of the PP plate was measured by TOF-SIMS (high spatial resolution mode).
FIG. 4 shows the TOF-SIMS measurement results after the reaction with the modifying reagent. A peak was confirmed at 433 as in Example 1. Therefore, it turns out that the stearyl alcohol of the PP board surface which was not able to measure conventionally by TOF-SIMS is detectable by the above operation. From this, the surface bleeding state of the antistatic agent in the PP plate can be understood.

Example 4
In Example 3, the catalyst was changed from TEDA to DBU (vapor pressure 7.14 × 10 ⁻¹ Pa), and similarly subjected to the reaction with the modifying reagent. After completion of the reaction, PP was obtained by TOF-SIMS (high spatial resolution mode). The surface of the plate was measured.

  FIG. 5 shows the TOF-SIMS measurement results after the reaction with the modifying reagent. A peak was confirmed at 433 as in Example 1. Further, the peak intensity was 15 times or more stronger than when TEDA was used. Therefore, it can be seen that stearyl alcohol can be detected with higher accuracy and higher sensitivity than when TEDA is used by using DBU as a catalyst.

  Moreover, when image measurement was performed by TOF-SIMS, the distribution state of stearyl alcohol that could not be detected by the conventional TOF-SIMS measurement could be detected on the PP plate surface. The results are also shown in FIG.

Example 5
The plant vital agent (stearyl alcohol) that appeared to be attached to the root surface was detected using the root of the plant as the measurement target by TOF-SIMS.
In Example 2, the copper plate was replaced with the root of the plant and similarly subjected to the reaction with the modifying reagent. After the reaction was completed, the surface of the root was measured by TOF-SIMS (high spatial resolution mode). The reaction temperature was 23 ° C. and the reaction time was 1 day.

  FIG. 6 shows the results of TOF-SIMS measurement after reaction with the modifying reagent. A peak was confirmed at 433 as in Example 1. Moreover, the result of the image measurement by TOF-SIMS is shown together in FIG. The distribution of stearyl alcohol could be detected on the root surface of the plant. Therefore, it can be seen that by the above operation, stearyl alcohol and its distribution state on the root surface of a plant, which could not be conventionally measured by TOF-SIMS, can be sufficiently detected.

Example 6
To compare the sensitivity of TOF-SIMS measurement before and after the modification reaction of a volatile organic compound having a hydroxyl group, a model sample in which 0.25 (w / w)% of stearyl alcohol was kneaded into a PP plate was TOF-SIMS. It was measured by.

  It used for reaction with a modification reagent like Example 4, and measured the PP board surface by TOF-SIMS (high spatial resolution mode) after completion | finish of reaction.

FIG. 7 shows the TOF-SIMS measurement results after the reaction between stearyl alcohol and the modifying reagent in the PP plate. A peak was confirmed at mass number 433 in the mass spectrum corresponding to the molecular weight of the modification product of stearyl alcohol. FIG. 8 shows the peak intensity comparison results after the reaction of stearyl alcohol and stearyl alcohol in the stearyl alcohol kneaded PP plate with the modifying reagent. Compared with the intensity of the peak of stearyl alcohol (mass number 269, [M−H] ⁻ structure) before the reaction, it was confirmed that the intensity increased by 3 digits or more.

Example 7
Stearic acid was used as a volatile organic compound having a carboxyl group. 20 μl of a 3 (w / v)% chloroform solution of stearic acid (vapor pressure 1.14 × 10 ⁻³ Pa) was cast on a copper plate, spin-coated and dried. This copper plate and modifying reagent 4- (dimethylamino) -phenylisocyanate (vapor pressure 2.57 × 10 ⁰ Pa) 30 mg (0.185 mmol) and 4-dimethylaminopyridine (vapor pressure 5.74 × 10 ¹ Pa) 5 mg ( 0.041 mmol), left in a closed container, and allowed to undergo a gas phase reaction at 37 ° C. for 24 hours. After the reaction, the copper plate surface was measured by TOF-SIMS (high mass resolution mode).

  The structure of the modification product of stearic acid is as follows.

FIG. 9 shows the TOF-SIMS measurement results after the reaction between stearic acid and the modifying reagent. When a peak near the mass number 402 in the mass spectrum corresponding to the molecular weight of the modification product of stearic acid was noted, a peak was confirmed at 403. Since this is a peak that is not confirmed in the copper plate before the reaction, it was considered to be a molecular ion peak ([M + H] ⁺ structure) of the modification reaction product newly generated by the reaction with the modification reagent. Therefore, it can be seen that volatile stearic acid, which has been difficult to measure with TOF-SIMS, can be detected by the above operation.

Example 8
In order to compare the sensitivity of TOF-SIMS measurement before and after the modification reaction of a volatile organic compound having a carboxyl group, lauric acid (vapor pressure 8.81 × 10 ⁻² Pa) is added to the PP plate at 0.25 (w / w) The model sample kneaded in% was used as the measurement target by TOF-SIMS.
In Example 7, the copper plate was replaced with a PP plate and subjected to a reaction with a modifying reagent in the same manner. After the reaction was completed, the surface of the PP plate was measured by TOF-SIMS (high spatial resolution mode).
The structure of the modification product of lauric acid is as follows.

FIG. 10 shows the TOF-SIMS measurement results after the reaction of lauric acid and lauric acid in the lauric acid kneaded PP plate with the modifying reagent. A peak was confirmed at mass number 319 ([M + H] ⁺ structure) in the mass spectrum corresponding to the molecular weight of the modification reaction product of lauric acid. FIG. 11 shows a comparison result of peak intensity after reaction between lauric acid and lauric acid in the lauric acid kneaded PP plate and the modifying reagent. It was confirmed that the intensity increased by two orders of magnitude or more as compared with the intensity of the peak of lauric acid (mass number 199, structure of [M−H] ⁻ ) before the reaction.

Example 9
In order to observe the temperature change of the modification reaction for the carboxyl group, 0.25 (w / w)% of lauric acid or oleic acid (vapor pressure 4.93 × 10 ⁻⁴ Pa) was kneaded into the PP plate. The model sample was used as a measurement object by TOF-SIMS. In Example 7, the copper plate was replaced with a PP plate and subjected to a reaction with a modifying reagent in the same manner. After the reaction was completed, the surface of the PP plate was measured by TOF-SIMS (high spatial resolution mode).
The structure of the modification product of oleic acid is as follows.

As in Example 8, lauric acid had a peak at 319, and oleic acid also had a peak at mass number 401 ([M + H] ⁺ structure) corresponding to the molecular weight of the modification reaction (FIG. 12). . FIG. 13 shows a graph of the relationship between the temperature change and the TOF-SIMS measurement result. It was confirmed that oleic acid had a maximum reaction peak at 35 ° C. and lauric acid at 23 ° C., and that the best reaction yield was obtained within a range of 20 to 40 degrees close to room temperature.

FIG. 1 shows TOF-SIMS measurement results before and after the reaction between stearyl alcohol on the copper plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 1. The upper row shows the results before the reaction, and the lower row shows the results after the reaction. FIG. 2 shows TOF-SIMS measurement results after reacting stearyl alcohol on the copper plate surface with the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 2. FIG. 3 illustrates the change in the volatility of stearyl alcohol in Example 2 when the reaction between stearyl alcohol on the copper plate surface and the modifying reagent 4- (dimethylamino) -phenylisocyanate was not performed. It is a figure to do. FIG. 4 shows TOF-SIMS measurement results after reaction of stearyl alcohol on the PP plate surface with the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 3. FIG. 5 shows the results of TOF-SIMS measurement (left figure) after the reaction between stearyl alcohol on the PP plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 4 and image measurement by TOF-SIMS. It is a result (right figure). FIG. 6 shows TOF-SIMS measurement results (right figure) after reaction of stearyl alcohol on the plant root surface with the modifying reagent 4- (dimethylamino) -phenylisocyanate in Example 5 and image measurement by TOF-SIMS. This is the result (left figure). In the figure on the left, “Total” is a distribution image combining all ions measured by TOF-SIMS. “433 / Total” is the distribution image of “433” below and the distribution image of “Total” "433" indicates that the image is a distribution image of a stearyl alcohol modification reaction product. FIG. 7 shows the results of TOF-SIMS measurement before and after the reaction between stearyl alcohol on the PP plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 6 (right figure), and image measurement by TOF-SIMS. It is a result (left figure). The upper part of the right figure shows the result before the reaction, and the lower part shows the result after the reaction. In the left figure, “269” and “433” indicate a stearyl alcohol distribution image and a stearyl alcohol modification reaction product distribution image. FIG. 8 is a result of comparing the TOF-SIMS peak intensities before and after the reaction between stearyl alcohol on the PP plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in FIG. FIG. 9 shows TOF-SIMS measurement results before and after the reaction between stearic acid on the copper plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 7. The upper row shows the results before the reaction, and the lower row shows the results after the reaction. FIG. 10 shows the results of TOF-SIMS measurement before and after the reaction of lauric acid on the PP plate surface with the modifying reagent 4- (dimethylamino) -phenylisocyanate in Example 8 (right figure), and image measurement by TOF-SIMS. It is a result (left figure). The upper row shows the results before the reaction, and the lower row shows the results after the reaction. In the left figure, “199” and “319” indicate a distribution image of lauric acid and a distribution image of a lauric acid modification reaction product. FIG. 11 shows the results of comparing the TOF-SIMS peak intensities before and after the reaction between lauric acid on the PP plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in FIG. FIG. 12 shows the results of TOF-SIMS measurement after the reaction of oleic acid on the PP plate surface with the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 9 (right figure) and image measurement by TOF-SIMS. It is a result (left figure). In the left figure, “401” indicates a distribution image of the lauric acid modification reaction product. FIG. 13 is a graph showing the relationship between the temperature and peak intensity of the reaction between lauric acid or oleic acid on the PP plate surface and the modifying reagent 4- (dimethylamino) -phenyl isocyanate in Example 9. The upper row is the result of lauric acid, and the lower row is the result of oleic acid.

Claims (6)

A method for detecting a volatile organic compound present on the surface of a substrate,
(1) reacting the compound with a volatile modifying reagent in the presence of a volatile catalyst that vaporizes under the conditions under which these reactions are carried out , and making the compound non-volatile; and (2) flight time A step of measuring the surface of the substrate with a type secondary ion mass spectrometer (TOF-SIMS) and detecting the compound,
A detection method.   The organic compound is at least one selected from the group consisting of hydroxyl group, carboxyl group, amino group, ether, ester, amide group, halogen, nitro group, cyano group, alkyne, alkene, phosphate group, carbonyl group, thiol group, and disulfide. The detection method according to claim 1, which has a functional group or structure.   The modifying reagent is isocyanate group, cyanide group, acid azide group, ethylene oxide, hydroxyl group, methoxy group, amino group, imino group, pyridyl group, pyrrolyl group, thiol group, alkene, halogen functional group, trimethylsilyl group, diazo group, carboxyl A compound having at least one group or structure selected from the group consisting of a group, a sulfonyl chloride group, an isothiocyanate group, an N-hydroxysuccinimide, a carbonyl group, a tosyl group, a mesyl group, maleimide, disulfide, hydrazine, hydrazide, and aziridine The detection method according to claim 1 or 2, comprising at least one selected from the group consisting of:   The detection method according to claim 3, wherein the modifying reagent has at least one selected from an amino group, an imino group, a pyridyl group, and a pyrrolyl group. The catalyst is pyridine, triethylenediamine (TEDA), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), 2-methyl-1,4-diazabicyclo [2.2.2] octane (Me -dabco) or 4-detection method according to any one of claims 1 to 4 dimethyl amino pyridine (DMAP). Claim 1-5 detection method according to any one of detecting organic compound as its distribution in the substrate surface.