Method and apparatus for screening samples containing isopropylated triphenyl phosphate

Abstract

A screening method of a sample containing isopropylated triphenyl phosphate, comprising the steps of: steps (3, 4) of obtaining, as a measured value, a content or a value reflecting the content of each of a plurality of compound groups of a compound group in which the total number of isopropyl groups as substituents of the three phenyl groups of triphenyl phosphate in the sample is 1, a compound group in which the total number is 2, and a compound group in which the total number is 3; and steps (5, 6) of determining that isopropylated triphenyl phosphate is contained in the sample based on the result of comparing the measured value with a threshold value determined in advance for each of the compound groups.

Description

Technical Field

[0001] This invention relates to a method and apparatus for screening samples containing isopropyltriphenyl phosphate. Background Technology

[0002] Phenol, isopropylated phosphate (PIP(3:1), CAS: 68937-41-7) is widely used as an additive to impart flame retardancy and plasticity to resin products such as polyvinyl chloride (PVC). In addition, PIP(3:1) also possesses abrasion resistance and compression resistance, and is therefore widely used as an additive in hydraulic fluids, adhesives, etc. In non-patent literature issued by the U.S. Environmental Protection Agency (EPA), PIP(3:1) is defined as a group of compounds having a molecular structure with triphenyl phosphate as the basic structure and each of the three phenyl groups having one or more isopropyl groups as substituents.

[0003] The EPA, based on the Toxic Substances Control Act (TSCA), classifies PIP (3:1) as a persistent, bioaccumulative, and toxic (PBT) substance (Non-Patent Literature 2). This restricts the export of products containing PIP (3:1) to the United States. To comply with this restriction, it is necessary to confirm beforehand that the products intended for export to the United States do not contain PIP (3:1).

[0004] Non-Patent Documents 3 and 4 describe methods for determining the amount of PIP (3:1) contained in a sample by analyzing the sample solution obtained from dissolving the sample using LC / MS and GC / MS. Furthermore, Non-Patent Document 5 describes a method for determining PIP (3:1) contained in a sample by using Py / TD-GC / MS, which combines a method of thermal desorption (TD) of components such as PIP (3:1) contained in the sample using a pyrolyzer (Py) that directly heats the sample with gas chromatography-mass spectrometry.

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-Patent Document 1: Office of Chemical Safety and Pollution Prevention, U.S. EPA, “Preliminary Information on Manufacturing, Processing, Distribution, Use, and Disposal: Phenol, isopropylated, phosphate(3:1)”, Support document for Docket EPA-HQ-OPPT-2016-073 (2017)

[0008] Non-Patent Document 2: News Releases from Headquarters, “EPA Finalizes Action Protecting Americans from PBT Chemicals”, United States Environmental Protection Agency, December 22, 2020, [Retrieved on August 20, 2021], Internet <URL:https: / / www.epa.gov / newsreleases / epa-finalizes-action-protecting-americans-pbt-chemicals>

[0009] Non-Patent Document 3: Martin Schlummera et al., “Analysis of flame retardant additives in polymer fractions of waste of electric and electronic equipment (WEEE) by means of HPLC-UV / MS and GPC-HPLC-UV”, Journal of Chromatography A, Volume 1064, Issue 1, 28 January 2005, Pages 39-51

[0010] Non-patent document 4: Thomas Roth et al., "Gas chromatographic determination ofphosphate-based flame retardants in styrene-based polymers from wasteelectrical and electronic equipment", Volume 1262, 2November 2012, Pages 188-195

[0011] Non-patent document 5: Hisaki Ishii, Kyohiko Kudo, Kenichi Obayashi, "Application news Thermal decomposition (thermal desorption)-GC / MS analysis of PIP (3:1) in いた resin", [online], June 2021, Shimadzu Corporation, [Retrieved on August 13, 2021], Internet<URL:https: / / www.an.shimadzu.co.jp / aplnotes / gcms / an_01-00191-jp.pdf> Summary of the Invention

[0012] The problem the invention aims to solve

[0013] PIP(3:1) comprises a large number of compounds with varying numbers or positions of isopropyl substitutions of the phenyl group. However, if mass spectrometry is used as described in Non-Patent Documents 3-5, the entire group of compounds with the same number of isopropyl substitutions can be determined in a single step by detecting an ion with a common mass-to-charge ratio. However, the composition ratios of compounds with different substitution numbers vary depending on manufacturing conditions, making it sometimes difficult to detect groups with low substitution ratios. Alternatively, even with the same composition ratio, the detection sensitivity of compounds with different substitution numbers differs, making it sometimes difficult to detect even groups with similar substitution ratios. Therefore, determining the presence of PIP(3:1) in a sample based on the detection of all compounds conforming to PIP(3:1) is very difficult.

[0014] To simplify the determination, it is considered to measure only a subset of all compound groups with different numbers of substituents. However, as mentioned above, the composition ratio (concentration) of each compound group in the product varies depending on the manufacturing conditions, and the detection sensitivity of each compound group also varies. Therefore, when screening samples such as products containing PIP (3:1), it is difficult to determine which compound group is appropriate to be measured. For example, when the content of the compound group to be measured is low or the detection sensitivity is low, there is a possibility that the presence of PIP (3:1) in the sample may be missed. In addition, when only one compound group is measured, if there are dopants with the same mass-to-charge ratio as that compound group, there is a possibility that the content of the dopant may be mistakenly interpreted as the content of that compound group, and the sample may be mistakenly identified as containing PIP (3:1) even though it does not actually contain PIP (3:1).

[0015] The problem to be solved by the present invention is to provide a screening technique that can easily and accurately determine whether isopropyltriphenyl phosphate is present in a sample of the analyte.

[0016] Solution for solving the problem

[0017] The screening method for samples containing isopropyltriphenyl phosphate, which was developed to solve the above problems, includes the following steps:

[0018] For each compound group in the sample, including groups of compounds where the sum of x, y, and z (represented by chemical formula 1 below) is 1, groups of compounds where the sum of x, y, and z is 2, and groups of compounds where the sum of x, y, and z is 3, the content of that compound group or a value reflecting that content is obtained as a determination value, where x, y, and z are the number of isopropyl groups as substituents in each phenyl group.

[0019] [Chemical Formula 1]

[0020] as well as

[0021] The sample is determined to contain isopropyltriphenyl phosphate based on the result obtained by comparing the measured value with a pre-determined threshold for the group of compounds corresponding to the measured value.

[0022] Furthermore, the screening apparatus for samples containing isopropyltriphenyl phosphate, which was completed in order to solve the above-mentioned problems, includes:

[0023] The measurement value acquisition unit acquires the content of each compound group in a sample from multiple compound groups among groups of compounds where the sum of x, y, and z (represented by the following chemical formula 1) is 1, 2, and 3, and obtains a value reflecting that content as a measurement value. Here, x, y, and z represent the number of isopropyl groups (substituents) present in each phenyl group.

[0024] [Chemical Formula 1]

[0025] as well as

[0026] The determination unit determines that the sample contains isopropyltriphenyl phosphate based on the result obtained by comparing the measured values ​​of the plurality of compound groups with a threshold predetermined for each compound group.

[0027] The effects of the invention

[0028] The isopropyltriphenyl phosphate (PIP(3:1)) used as the screening target compound in this invention belongs to the group of compounds in Formula 1 above, where x, y, and z are all 1 or more. The compounds represented by Formula 1 above include the group of compounds where x, y, and z each have values ​​from 0 to 5. In the manufacture of a product containing PIP(3:1), not only is PIP(3:1) generated, but also compounds with any phenyl group that does not have an isopropyl group (R in the above formula) are generated as byproducts. Furthermore, in most cases, the product containing PIP(3:1) contains more of the compound with fewer isopropyl substitutions. This invention was made based on these insights obtained by the inventors.

[0029] In this invention, the content or a value reflecting the content of multiple compound groups, including groups of compounds having the same basic structure as PIP(3:1) as triphenyl phosphate and a total number of isopropyl groups (substituents of the three phenyl groups) of 1, 2, and 3, is obtained as the measured value. In samples such as products containing PIP(3:1), there are more compounds with fewer isopropyl substitutions, which are the target compounds in this invention; therefore, accurate measured values ​​can be obtained. Thus, by comparing the measured values ​​of each target compound with a predetermined threshold, it can be accurately determined whether the sample to be analyzed contains PIP(3:1). Furthermore, the threshold can be a different value for each compound group or a common value. Additionally, it is rare for multiple target compounds to have the same mass-to-charge ratio in a single sample; therefore, by measuring multiple compound groups as in this invention, false determinations can be prevented. Moreover, screening is easier compared to measuring all compound groups with different numbers of substituents. Attached Figure Description

[0030] Figure 1 This is a structural diagram of the main parts of a Py / TD-GC / MS apparatus, which is an embodiment of a screening device for samples containing isopropyltriphenyl phosphate as described in this invention.

[0031] Figure 2 This is an example of the measurement conditions used in this embodiment.

[0032] Figure 3 These are the monitoring m / z and threshold values ​​for the compound group in this embodiment.

[0033] Figure 4 This is the calibration curve used in this embodiment.

[0034] Figure 5 This is a flowchart of an embodiment of a screening method for samples containing isopropyltriphenyl phosphate as described in this invention.

[0035] Figure 6 This is a diagram illustrating the determination result in this embodiment.

[0036] Figure 7 It is a mass chromatogram obtained by measuring the number of substituents in a group of compounds contained in a resin sample used as a standard sample.

[0037] Figure 8 It is a mass chromatogram obtained by measuring the number of substituents in a group of compounds contained in a resin sample used as an industrial product.

[0038] Figure 9This is a diagram illustrating the determination method in variation example 1.

[0039] Figure 10 This is a diagram illustrating the determination method in variation example 2.

[0040] Figure 11 This is a diagram illustrating the determination method in variation example 3. Detailed Implementation

[0041] The following describes, with reference to the accompanying drawings, embodiments of the screening method and apparatus for samples containing isopropylated triphenyl phosphate (Phenol, isopropylated phosphate: PIP(3:1), CAS: 68937-41-7) as described in this invention.

[0042] In this embodiment, a pyrolyzer / thermal desorption unit-gas chromatography-mass spectrometry (Py / TD-GC / MS) 1 is used to screen analyte samples that may contain PIP (3:1). Examples of analyte samples in this embodiment include resin products, hydraulic fluids, and adhesives. In Non-Patent Document 1, PIP (3:1) is defined as a group of compounds represented by the following chemical formula 1 (where x, y, and z are the number of isopropyl groups present as substituents in each phenyl group), where x, y, and z are all 1 or more.

[0043] [Chemical Formula 1]

[0044]

[0045] The Py / TD-GC / MS1 is generally distinguished by a gas chromatography (GC) section 10, a mass spectrometry (MS) section 20, and a control / processing section 30. The gas chromatography section 10 includes a sample vaporization chamber 11, a pyrolyzer (Py) 12, a carrier gas flow path 13 connected to the sample vaporization chamber 11, and a column 14 connected to the outlet of the sample vaporization chamber 11. The pyrolyzer 12 can also be used as a thermal desorption (TD) device by varying its heating temperature. The column 14 is housed inside a column oven 15. The column 14 in both the pyrolyzer 12 and the column oven 15 is heated to a predetermined temperature by a heating mechanism (not shown).

[0046] The mass spectrometry analysis unit 20 includes an electron ionization source 22, an ion lens 23, a quadrupole mass filter 24, and an ion detector 25 within a vacuum chamber 21. Sample components separated over time inside the column 14 are sequentially introduced into the electron ionization source 22 and ionized by irradiation with thermionic electrons released from the filament (not shown).

[0047] The control / processing unit 30 has a storage unit 31. The storage unit 31 stores a method document describing the measurement conditions for the sample. The measurement conditions described in the method document include the temperature of the pyrolyzer 12, the temperature of the column 14, the type and flow rate of the carrier gas, the range of the mass-to-charge ratio of the analyte in the scanning measurement, the retention time of each compound included in multiple compound groups (compound groups 1 to 3), and information on the mass-to-charge ratio (monitoring m / z) of the ion (target ion) for each compound group. Figure 2 and Figure 3 This is an example of the measurement conditions described in the method document used in the Py / TD-GC / MS1 of this embodiment (the retention times of each compound are omitted). Additionally, the storage unit 31 also stores information on the thresholds (L1 to L3) used for comparing with the measured values ​​(described later), and information on the calibration curves prepared based on the measurement results of the standard samples (described later). Figure 4 In this embodiment, the values ​​of thresholds L1 to L3 can also be set as the detection lower limit or a value close to it to determine whether PIP (3:1) is present.

[0048] The control / processing unit 30 comprises a standard sample measurement unit 32, a calibration curve generation unit 33, an actual sample measurement unit 34, a measurement value acquisition unit 35, a judgment unit 36, and an information output unit 37 as functional blocks. The control / processing unit 30 is essentially a general-purpose personal computer, and these functional blocks are implemented by a pre-installed screening program executed by a processor. Furthermore, the control / processing unit 30 is connected to an input unit 4 for user input operations and a display unit 5 for displaying various information.

[0049] Next, refer to Figure 5 The flowchart below illustrates the filtering process using Py / TD-GC / MS1 in this embodiment.

[0050] In this embodiment, a standard sample is measured before screening the actual sample (step 1). The standard sample used in this embodiment is a resin sample containing known amounts of multiple groups of compounds represented by the above chemical formula 1 (x, y, and z are the number of isopropyl groups that are substituents in the phenyl group. These include groups of compounds whose sum of x, y, and z is 1 to 3). Furthermore, the standard sample measurement only needs to be performed once; the measurement of the standard sample can be omitted by storing the calibration curve prepared based on the results in the storage unit 31 beforehand. Although a resin sample is used as the standard sample in this embodiment, the type of standard sample can be appropriately selected according to the type of sample to be measured (usually, a sample of the same type as the sample to be measured is selected).

[0051] When the user places the standard sample into the pyrolyzer 12 and instructs the standard sample to be measured, the standard sample measurement unit 32 reads the method document stored in the storage unit 31 (see reference). Figure 2 and Figure 3 The determination is performed based on the method documentation. Specifically, firstly, the pyrolyzer 12 is gradually heated to detach various compounds containing PIP (3:1) from the standard sample, which are then introduced into column 14 along with a carrier gas flow. The compounds introduced into column 14 are separated over time within the column based on the magnitude of their interaction with the liquid phase and then elute. The compounds elute from column 14 are sequentially introduced into electron ionization source 22.

[0052] Ions generated by the electron ionization source 22 are converged by the ion lens 23 to the vicinity of the central axis (ion optical axis C) in the direction of flight, and then incident on the quadrupole mass filter 24. They are separated according to the mass-to-charge ratio and detected by the ion detector 25. The output signal from the ion detector 25 is sequentially sent to the storage unit 31 and stored therein.

[0053] In the determination of the standard sample, scanning measurements and selected ion monitoring (SIM) measurements are repeatedly performed in the mass spectrometry analysis unit 20. Specifically, the following measurements are set as a group and performed repeatedly: a scanning measurement that scans the mass-to-charge ratio of ions passing through the quadrupole mass filter 24 within a specified range (in this embodiment, the m / z range is 50 to 1000); and a SIM measurement that fixes the mass-to-charge ratio of ions passing through the quadrupole mass filter 24 to the mass-to-charge ratio of the target ion of each compound group for a specified time. For the compound group with 1 substituent (compound group 1), the compound group with 2 substituents (compound group 2), and the compound group with 3 substituents (compound group 3) in this embodiment, SIM measurements are performed on the target ion (the ion with monitored m / z). Therefore, in this embodiment, a single scanning measurement and three SIM measurements are grouped together.

[0054] When the standard sample measurement is completed, the calibration curve generation unit 33 reads the output signal of the ion detector 25 stored in the storage unit 31. Then, a total ion current chromatogram is generated using the output signal obtained during the scan measurement. Additionally, mass chromatograms of each of the compound groups 1 to 3 are generated using the output signals obtained during the three SIM measurements. Compound groups 1 to 3 contain multiple compounds with different isopropyl substitution positions; therefore, multiple mass peaks typically appear in each mass chromatogram. In this embodiment, calibration curves for each of the compound groups 1 to 3 are generated based on the sum of the peak areas (or peak heights) of these multiple mass peaks appearing on the mass chromatogram of a compound group and the amount of compounds 1 to 3 contained in the standard sample. Figure 4(Step 2). Here, a calibration curve is created by connecting the origin to a measurement point. However, the calibration curve can also be created using the results obtained from measuring multiple standard samples with different contents of compounds 1 to 3. Additionally, the peak areas or peak heights of the multiple compounds (compounds with different substituent positions) included in each of compounds 1 to 3 are summed. However, one or more of these compounds (e.g., compounds with high measurement sensitivity) can also be selected to create the calibration curve. The calibration curves for compounds 1 to 3 created here are stored in storage unit 31.

[0055] In this embodiment, the retention time information of each compound included in compound groups 1 to 3 is pre-recorded in the method file stored in storage unit 31 (the retention time is known), but a retention index can also be used when the retention time is unknown. When using the retention index, a n-alkane sample is measured separately from the standard sample. The n-alkane sample refers to a standard sample containing multiple compounds with different hydrocarbon chain lengths, used to obtain a retention index based on the retention time of each compound. The retention index Ix of compound x is represented by the following formula (1).

[0056] Ix=100(Cn+i-Cn){(tx-tn) / (tn+i-tn)}+100Cn(1)

[0057] Here, Cn and Cn+i are the carbon numbers of the n-alkanes that are between the retention times of the compound and before or after the retention times of the compound, respectively; tx is the retention time of compound x; and tn and tn+i are the retention times of the n-alkanes that are between the retention times of the compound and before or after the retention times of the compound.

[0058] Afterwards, the user inputs the information of the sample to be analyzed (sample name, sample quantity). When the initial sample is placed in the pyrolyzer 12 and the measurement is started, the actual sample measurement unit 34, like the standard sample measurement unit 32, reads the method file (see reference) stored in the storage unit 31. Figure 2 and Figure 3 The determination is performed based on the information described in the method document (step 3). The output signal from the ion detector 25 is also sequentially sent to and stored in the storage unit 31 in the same manner as when determining the standard sample.

[0059] When the measurement of the actual sample is completed, the measurement value acquisition unit 35 reads the output signal of the ion detector 25 stored in the storage unit 31, and similarly as when measuring the standard sample, prepares a total ion current chromatogram and mass chromatograms corresponding to compound groups 1 to 3 respectively. Then, the area (or peak height) of the mass peak of each compound belonging to that compound group on the mass chromatogram of each of compound groups 1 to 3 is calculated, and their sum is calculated. Then, based on the calibration curve stored in the storage unit 31, the content of each compound group 1 to 3 is determined (step 4).

[0060] When the contents of compounds 1 to 3 are obtained, the determination unit 36 ​​calculates the concentration of each compound group 1 to 3 based on the weight of the sample to be analyzed (the weight of the sample placed in the pyrolyzer 12) and its contents. Next, the threshold values ​​L1 to L3 corresponding to each compound group 1 to 3 are read and compared (step 5). (Refer to...) Figure 6 Then, determine whether the concentrations of multiple compound groups in compound groups 1 to 3 exceed the threshold (step 6).

[0061] If the number of compound groups exceeding the threshold concentration is 0 or 1 ("No" in step 6), the determination unit 36 ​​determines that the sample is highly likely to not contain PIP (3:1). On the other hand, if the concentrations of multiple compound groups exceed the threshold ("Yes" in step 6), refer to... Figure 6 The determination unit 36 ​​determines that the sample is highly likely to contain PIP (3:1). When the determination is highly likely to contain PIP (3:1), the information output unit 37 causes the display unit 5 to display the situation that the sample is highly likely to contain PIP (3:1) (step 7). In addition, the number of compound groups measured and the number of compound groups whose concentration exceeds the threshold are simultaneously displayed (for example, displayed as (number of compound groups with concentration ≥ threshold) / number of compound groups of the measured object (2 / 3, 3 / 3, etc.)). This makes it easier to know the probability of containing PIP (3:1). Alternatively, if the concentration of all compound groups exceeds the threshold, the color indicating the presence of PIP (3:1) (e.g., red) can be used, and if the concentration of some compound groups exceeds the threshold, the color indicating the possible presence of PIP (3:1) (e.g., yellow) can be used to encourage the user to perform more detailed analysis.

[0062] When the above-described processing performed by the determination unit 36 ​​and the information output unit 37 is completed, the actual sample measurement unit 34 checks whether there are any unmeasured samples. If there are unmeasured samples ("Yes" in step 8), it returns to step 3 and repeats the same process. If there are no unmeasured samples ("No" in step 8), the series of processes ends.

[0063] As described above, in this embodiment, in order to determine whether the sample containing PIP(3:1) is present, compounds having the same basic structure as PIP(3:1) and having an isopropyl substitution number of 1 to 3 are measured. This is based on the following observation obtained by the inventors from measuring various samples containing PIP(3:1): in samples containing PIP(3:1), not only PIP(3:1) is present, but also compounds with any phenyl group without an isopropyl R are present as byproducts, and in most cases, their content is greater than that of PIP(3:1).

[0064] exist Figure 7 The image shows the total ion current chromatogram (TIC) and mass chromatograms of compounds with different numbers of substituents (0-6) obtained by adding a standard solution prepared from PIP (3:1) sold as a standard reagent and a PVC solution to a sample cup for Py / TD-GC / MS analysis, respectively, to a PIP (3:1) concentration of 1% in the resin (equivalent to 0.5 mg of resin weight). Additionally, in... Figure 8 The figure shows the TIC and mass chromatograms of compounds with different numbers of substituents (0-6) obtained by adding solutions prepared from PIP (3:1) sold as industrial products and PVC solutions to sample cups for Py / TD-GC / MS analysis, respectively, to a PIP (3:1) concentration of 1% (equivalent to 0.5 mg of resin weight). The notation iPr:x in the figure indicates a compound group with x isopropyl substitutions. Additionally, the m / z value indicates the mass-to-charge ratio of the target ion in that compound group (monitoring m / z), and the value in parentheses indicates the chromatogram magnification. These are examples of measurements, but it is evident that samples with 0-3 substitutions were detected in each sample.

[0065] Furthermore, mass spectrometry analysis of compounds with different numbers of substituents revealed a tendency for higher detection sensitivity with fewer substituents. Therefore, as in this embodiment, the concentrations of compounds 1 to 3, which are more abundant in samples containing PIP (3:1) and have high detection sensitivity, were used as the criterion for selection. This allowed for the screening of samples containing PIP (3:1) without any missed detections.

[0066] When manufacturing products containing PIP(3:1), not only PIP(3:1) is generated, but also compounds with any phenyl group that do not have an isopropyl group (R in the above chemical formula 1) are generated as byproducts. It is not easy to selectively remove these byproducts, selectively extract only PIP(3:1), or manufacture only PIP(3:1) without generating byproducts. Therefore, products containing PIP(3:1) are highly likely to contain these byproducts. Thus, it is appropriate to use a method that replaces the direct measurement of PIP(3:1) and determines the presence of PIP(3:1) based on the presence of compounds 0-3, which are byproducts of PIP(3:1).

[0067] In the above embodiments, the concentrations of compound groups 1 to 3 were compared with a threshold. However, it is also possible to measure only two of the compound groups 1 to 3. If only one compound group is measured, in the presence of dopants that generate ions with the monitoring m / z set for that compound group, even if the dopants are detected, it may be mistakenly considered that the compound group has been measured, leading to the possibility of false screening. Therefore, it is preferable to compare the concentrations of multiple compound groups with a threshold. In addition, in the above embodiments, the concentration of each compound group was determined and compared with a threshold. However, if the weight of the sample being measured is fixed, a content threshold can also be set.

[0068] The above embodiment is one example, and modifications can be made appropriately in accordance with the spirit of the present invention. Several variations are described below.

[0069] <Variation Example 1>

[0070] In the above embodiments, for multiple compound groups 1 to 3, the concentration of the analyte in the sample was compared with a threshold, but as Figure 7 and Figure 8 As shown, the sample containing PIP (3:1) also contains a significant amount of triphenyl phosphate (with 0 substituents) and compounds with four isopropyl groups, which can also be determined with high sensitivity. Therefore, the target group can be expanded to compounds 0–4 (with 0–4 substituents), and the concentrations of multiple compounds within this group can be compared with threshold values. Figure 9 The example shown compares the concentrations of compounds 0-4 with a threshold (an example where the concentrations of compounds 0-3 are above the threshold, and only the concentration of compound 4 is below the threshold). By expanding the range of compounds to be measured, determinations can be made based on the measurements of more compounds, thus increasing the accuracy of the determination.

[0071] <Variation Example 2>

[0072] In the above embodiments, thresholds were set for each of the compound groups 1 to 3, and samples were screened based on the results obtained by comparing the concentrations of compound groups 1 to 3 contained in the analyte sample with each threshold. However, in addition, it is also possible to set a threshold (total threshold) for the total concentration of the compound groups (e.g., compound groups 1 to 3) that are being measured, and to screen samples by comparing the total concentration of multiple compound groups obtained through measurement with the threshold. Figure 10 The example shown is an example of comparing the total concentration of compounds 1 to 3 with a total threshold (an example where the total concentration of compounds 1 to 3 does not exceed the total threshold).

[0073] Regarding PIP(3:1), the ratio of the content of each substituted compound group may change depending on manufacturing conditions, etc., thus, there may be cases where the concentration of a specific compound group is lower. Furthermore, due to the influence of other components contained in the sample, the ionization of a specific compound group may be suppressed (ion suppression), resulting in a decrease in the detection sensitivity. In Modified Example 2, even in these cases, the possibility of missing a sample containing PIP(3:1) can be reduced by comparing the sum of the measured values ​​of other compound groups with a threshold.

[0074] <Variation Example 3>

[0075] In the above embodiments, the content of each compound group was determined based on the peak area (or peak height) of the mass chromatogram, and the concentration of each compound group was determined based on the content and the weight of the sample. However, if the apparatus for measuring the standard sample is the same as or of the same type as the apparatus for measuring the analyte sample, and the measurement conditions are considered substantially the same, it is also possible to configure the method to compare the peak area or peak height with a threshold. Figure 11 The example shown compares the peak heights to threshold values ​​for each compound group (1-3) (examples where the peak heights for all compounds in groups 1-3 are above the threshold). This eliminates the need to compare the measured peak area and peak height with a calibration curve to determine the content, thus allowing for a simpler determination.

[0076] PIP(3:1) is a collection of a large number of compounds, therefore, there are situations where even standard samples cannot accurately determine the content and concentration of each compound. In Modification 3, even in such cases, it is possible to use the measurement results of standard samples, etc., as a benchmark and use their peak area and peak height as thresholds to screen and determine whether the target compound group is contained at a higher concentration than the standard sample.

[0077] In the above embodiments and variations, it was explained that the structure of a sample containing PIP (3:1) was screened by using Py / TD-GC / MS determination. However, similar to the above embodiments or variations, other determination methods can be used as long as the compound group can be determined. For example, the following method can be used: performing chromatography using only a chromatographic apparatus (gas chromatography, liquid chromatography, or other methods that detect each compound by spectrophotometry) to determine each compound separated in the column. However, it is possible to determine multiple compounds with the same number of substitutions using mass spectrometry at a common monitoring m / z as described above, therefore, mass spectrometry is preferred. In addition, when using Py / TD, there is no need for pretreatment such as dissolving the sample in a solvent, therefore, Py / TD is preferred. Alternatively, mass spectrometry methods that do not utilize chromatographic separation (TD-MS) can also be used.

[0078] [Way]

[0079] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following approaches.

[0080] (First item)

[0081] A screening method for samples containing isopropyltriphenyl phosphate according to one aspect of the present invention includes the following steps:

[0082] For each compound group in the sample, including groups of compounds where the sum of x, y, and z (represented by chemical formula 1 below) is 1, groups of compounds where the sum of x, y, and z is 2, and groups of compounds where the sum of x, y, and z is 3, the content of that compound group or a value reflecting that content is obtained as a determination value, where x, y, and z are the number of isopropyl groups as substituents in each phenyl group.

[0083] [Chemical Formula 1]

[0084] as well as

[0085] The sample is determined to contain isopropyltriphenyl phosphate based on the result obtained by comparing the measured value with a pre-determined threshold for the group of compounds corresponding to the measured value.

[0086] (Item 6)

[0087] Furthermore, another aspect of the present invention relates to a screening device for a sample containing isopropyltriphenyl phosphate, comprising:

[0088] The measurement value acquisition unit acquires the content of each compound group in a sample from multiple compound groups among groups of compounds where the sum of x, y, and z (represented by the following chemical formula 1) is 1, 2, and 3, and obtains a value reflecting that content as a measurement value. Here, x, y, and z represent the number of isopropyl groups (substituents) present in each phenyl group.

[0089] [Chemical Formula 1]

[0090] as well as

[0091] The determination unit determines that the sample contains isopropyltriphenyl phosphate based on the result obtained by comparing the measured values ​​of the plurality of compound groups with a threshold predetermined for each compound group.

[0092] The isopropyltriphenyl phosphate (PIP(3:1)) selected as the target compound in the screening method of the first item and the screening device of the sixth item is a compound group in which x, y, and z are all 1 or more in the above chemical formula 1. When manufacturing a product containing PIP(3:1), not only PIP(3:1) is generated, but also compounds with any phenyl group that does not have an isopropyl group (R in the above chemical formula 1) are generated as byproducts. Furthermore, in most cases, the product containing PIP(3:1) contains more compounds with fewer isopropyl group substitutions.

[0093] In the screening method of the first item and the screening apparatus of the sixth item, the content or a value reflecting the content of multiple compound groups, which have the same basic structure as PIP(3:1) as triphenyl phosphate and a total number of isopropyl groups as substituents of the three phenyl groups being 1, 2, and 3, is obtained as a measured value. In samples such as products containing PIP(3:1), a relatively large amount of the compound groups with fewer isopropyl substitutions, which are target compounds in the screening method of the first item and the screening apparatus of the sixth item, are included. Therefore, the presence of PIP(3:1) can be determined without any omissions. Furthermore, the presence of PIP(3:1) in the analyte sample can be accurately determined by comparing the measured value of each target compound with a predetermined threshold. Moreover, the threshold can be a different value for each compound group or a common value. Furthermore, it is rare for multiple target compounds to have dopants with the same mass-to-charge ratio present in a single sample. Therefore, it is possible to prevent false positives by measuring multiple groups of compounds, as described in the first screening method and the sixth screening device. Moreover, screening is simpler compared to measuring all groups of compounds with different numbers of substituents.

[0094] (Second item)

[0095] In the screening method for samples containing isopropyltriphenyl phosphate described in the first item,

[0096] In the step of obtaining the measured value, the content of triphenyl phosphate and / or the group of compounds whose sum of x, y, and z represented by the above chemical formula 1 is 4 or more in the sample, or the value reflecting the content, is also obtained as the measured value.

[0097] In the second screening method, triphenyl phosphate (compounds with 0 substituents) and compounds with 4 or more substituents are also included as the test objects. The test values ​​of more compound groups are compared with the threshold. Therefore, it is possible to screen samples containing isopropyltriphenyl phosphate with higher accuracy.

[0098] (Third item)

[0099] In the screening method for samples containing isopropyltriphenyl phosphate as described in the first or second item,

[0100] In the step of comparing with the threshold, the sum of the measured values ​​of the plurality of compound groups is also compared with a predetermined threshold.

[0101] In the third screening method, the screening of samples containing isopropyltriphenyl phosphate is based not only on the results obtained by comparing the measured values ​​of each compound group with a predetermined threshold, but also on the results obtained by comparing the sum of the measured values ​​of multiple compound groups with a predetermined threshold. When manufacturing products containing PIP (3:1), the proportions of each compound group can vary depending on the manufacturing conditions, and there is a possibility that the compound groups may be contained in a distribution different from the proportions envisioned when setting the threshold. Furthermore, even when the compound groups are contained in the envisioned proportions, there is a possibility that the ionization of certain compound groups may be suppressed by other components contained in the sample (ion suppression). In the third screening method, the determination of whether PIP (3:1) is contained is based not only on the results obtained by comparing each compound group with the threshold, but also on the results obtained by comparing the sum of the measured values ​​of multiple compound groups with the threshold. Therefore, the possibility of missing the detection of PIP (3:1) is reduced.

[0102] (Item 4)

[0103] In the screening method for samples containing isopropyltriphenyl phosphate described in any of the first to third items,

[0104] In the step of obtaining the measured value, data of the measured peak corresponding to each of the plurality of compound groups are obtained, and the height or area of ​​the measured peak, which reflects the content, is obtained as the measured value.

[0105] In the fourth screening method, there is no need to go through the process of determining the content of the compound group itself, thus making it easier to screen samples containing isopropyltriphenyl phosphate.

[0106] (Item 5)

[0107] In the screening method for samples containing isopropyltriphenyl phosphate described in any of the first to fourth items,

[0108] If the measured value of only a portion of the compound groups exceeds the predetermined threshold, information is output to urge confirmation of the sample.

[0109] In the fifth screening method, information is output to prompt confirmation of the sample when only a portion of the compound group's measured value exceeds the threshold. Therefore, the possibility of missing samples containing isopropyltriphenyl phosphate can be reduced with higher accuracy.

[0110] Explanation of reference numerals in the attached figures

[0111] 1: Pyrolysis unit / thermal desorption-gas chromatography-mass spectrometry system; 10: Gas chromatography section; 11: Sample vaporization chamber; 12: Pyrolysis unit; 13: Carrier gas flow path; 14: Column; 15: Column oven; 20: Mass spectrometry analysis section; 21: Vacuum chamber; 22: Electron ionization source; 23: Ion lens; 24: Quadrupole mass filter; 25: Ion detector; 30: Control / processing section; 31: Storage section; 32: Standard sample determination section; 33: Calibration curve preparation section; 34: Actual sample determination section; 35: Measurement value acquisition section; 36: Judgment section; 37: Information output section; 4: Input section; 5: Display section.

Claims

1. A method for screening samples containing isopropyltriphenyl phosphate, comprising the following steps: For each compound group in the sample, including groups of compounds where the sum of x, y, and z (represented by chemical formula 1 below) is 1, groups of compounds where the sum of x, y, and z is 2, and groups of compounds where the sum of x, y, and z is 3, the content of that compound group or a value reflecting that content is obtained as a determination value, where x, y, and z are the number of isopropyl groups as substituents in each phenyl group. [Chemical Formula 1] The measured value is compared with a predetermined threshold for the group of compounds corresponding to that measured value; and Based on the results of the comparison, it was determined that the sample contained isopropyltriphenyl phosphate.

2. The screening method for samples containing isopropyltriphenyl phosphate according to claim 1, wherein, In the step of obtaining the measured value, the content of triphenyl phosphate and / or the group of compounds whose sum of x, y, and z represented by the above chemical formula 1 is 4 or more in the sample, or the value reflecting the content, is also obtained as the measured value.

3. The screening method for samples containing isopropyltriphenyl phosphate according to claim 1, wherein, In the step of comparing with the threshold, the sum of the measured values ​​of the plurality of compound groups is compared with a predetermined threshold.

4. The screening method for samples containing isopropyltriphenyl phosphate according to claim 1, wherein, In the step of obtaining the measured value, data of the measured peak corresponding to each of the plurality of compound groups are obtained, and the height or area of ​​the measured peak, which reflects the content, is obtained as the measured value.

5. The screening method for samples containing isopropyltriphenyl phosphate according to claim 1, wherein, If the measured value of only a portion of the compound groups exceeds the predetermined threshold, information is output to urge confirmation of the sample.

6. A screening device for a sample containing isopropyltriphenyl phosphate, comprising: The measurement value acquisition unit acquires the content of each compound group in a sample from multiple compound groups among groups of compounds where the sum of x, y, and z (represented by the following chemical formula 1) is 1, groups of compounds where the sum of x, y, and z is 2, and groups of compounds where the sum of x, y, and z is 3, and obtains a value reflecting that content as a measurement value. x, y, and z represent the number of isopropyl groups that act as substituents in each phenyl group. [Chemical Formula 1] The measurement comparison unit compares the measured values ​​of the plurality of compound groups with a threshold predetermined for each of the compound groups; as well as The determination unit determines, based on the comparison result of the measured value comparison unit, that the sample contains isopropyltriphenyl phosphate.

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