CN117413180A

CN117413180A - Method for determining phthalic acid esters and brominated flame retardant compounds and gas chromatographic column used for method

Info

Publication number: CN117413180A
Application number: CN202180098937.5A
Authority: CN
Inventors: 工藤恭彦
Original assignee: Shimadzu Corp
Current assignee: Shimadzu Corp
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2024-01-16
Also published as: JPWO2022269763A1; WO2022269763A1; JP7552901B2

Abstract

A method for determining phthalate esters and brominated flame retardant compounds, comprising: a step 41 of heating a sample containing a target compound belonging to at least one of phthalic acid esters, polybrominated diphenyl groups, and polybrominated diphenyl ether groups, and gasifying the target compound contained in the sample; and a step 42 of heating the analytical column 14 to a temperature lower than the highest temperature at which the target compound is gasified, the analytical column 14 comprising: a separation column 142 provided inside with a stationary phase 1421 for separating a target compound; and a protection column 141 integrally provided with the separation column at an inlet side of the separation column without using a connection member; step 2 of introducing the vaporized target compound into the analytical column 14; and a step 44 of detecting the target compound flowing out from the separation column 142.

Description

Method for determining phthalic acid esters and brominated flame retardant compounds and gas chromatographic column used for method

Technical Field

The present invention relates to a method for measuring phthalic acid esters and brominated flame retardant compounds, and a gas chromatographic column used for carrying out the method.

Background

Phthalates (di (2-ethylhexyl) phthalate (DEHP), butylbenzyl phthalate (BBP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP)), polybrominated biphenyls (polybrominated biphenyls, PBBs, formula C) as brominated flame retardant compounds ₁₂ H _(10-n) Br _n (1.ltoreq.n.ltoreq.10)) and polybrominated diphenyl ether group (polybrominated diphenyl ethers, PBDEs, molecular formula C) ₁₂ H _(10-m) Br _m O (1.ltoreq.m.ltoreq.10)) is designated as a compound to be controlled in the RoHS instruction, and the total content of phthalic acid esters, PBBs and PBDEs allowed in each part such as a resin contained in an electrical and electronic equipment product in Europe export is specified.

In the determination of phthalic acid esters, PBBs and PBDEs contained in the resin sample, a thermal cracking-gas chromatography/mass spectrometry (Py-GC/MS) method, a pyrolyzer/thermal desorption-gas chromatography/mass spectrometry (Py/TD-GC/MS) method was used. In the Py-GC/MS method, a container containing a resin sample is introduced into a pyrolyzer and heated to pyrolyze the resin, and phthalic acid esters, PBBs, and PBDEs (hereinafter, these are collectively referred to as "management compounds") contained in the pyrolyzed product and the resin sample are introduced into a gas chromatograph. In Py-GC/MS, for example, the resin sample is heated to about 600 ℃. In the Py/TD-GC/MS method, a container containing a resin sample is introduced into a pyrolyzer and heated to a temperature equal to or lower than the temperature at which pyrolysis of the resin occurs, whereby a control compound contained in the resin is released from the resin and introduced into gas chromatography. In Py/TD-GC/MS, for example, the resin sample is heated to about 340 ℃.

In the Py-GC/MS method, not only the management compound, the pyrolysate of the resin and the compound (the inclusion compound) other than the management compound contained in the resin sample are also introduced into the gas chromatograph. In the Py/TD-GC/MS method, a pyrolysate and a impurity compound generated by pyrolysis of a part of a resin sample are also introduced into a gas chromatograph. Since the temperature of the separation column at the time of measuring these control compounds is lower than the temperature at the time of heating the resin sample in the pyrolyzer (for example, about 300 ℃ or lower), a part of the decomposed products and the impurity compounds of the resin sample adhere to and remain in the separation column, and the content of the separation column is easily contaminated. If the separation column is contaminated, the peak of the chromatogram will be smeared or the reproducibility and quantitative accuracy of the measurement will be impaired when the control compound is measured. Therefore, in the case where the separation column is deteriorated, it is necessary to cut off the deteriorated inlet portion or replace the separation column with a new one. In the use of various resin components in electric and electronic equipment products, it is sometimes required to measure the amount of a controlling compound contained in these resin components at a high frequency. However, if the above operation is performed every time the separation column is deteriorated, the measurement efficiency becomes poor. Accordingly, it has been proposed to install a guard column at the inlet of a separation column of gas chromatography to suppress the internal contamination of the separation column (for example, non-patent documents 1 and 2). This can prolong the life of the separation column, reduce the frequency of the above operation, and improve the measurement efficiency.

Prior art literature

Non-patent literature

Non-patent document 1: front-Lab company, "PBDE column-specific UA protection column kit Ph for analysis of phthalic acid esters", [ on-line ], [2021, 6 th and 16 th retrieval ], internet < URL: https:// www.frontier-lab.com/packages/file/products/UA_guard_column_J_V1.0.pdf >

Non-patent document 2: bjorklund et al, "Influence of the injection technique and the column system on gas chromatographic determination of polybrominated diphenyl ethers", journal of Chromatography A,1041, (2004), pp.201-210

Non-patent document 3: frontier-Lab company, "importance of inactivity of various sample cups in Thermal Desorption (TD) -GC/MS analysis of phthalic acid esters", [ on line ], [ search of 6 th month 7 of 2021 ], internet < URL: https:// www.frontier-Lab. Com/processes/file/technical-note/PY A1-092.Pdf >

Non-patent document 4: yukihiko Kudo, et al, "Development of a screening me thod for phthalate esters in polymers using a quantitative database in comb ination with pyrolyzer/thermal desorption gas chromatography mass spectro metry", journal of Chromatography A, volume 1602,27September 2019,Pages 441-449

Non-patent document 5: international Electrotechnical Commission, "Determination of certain substances in electrotechnical products-Part 3-3:screening-Polybrominated biphenyls, polybrominated diphenyl ethers and phthalates in polymers by gas chromatography-mass spectrometry using a pyrolyzer/thermal desorption accessory (Py/TD-GC-MS)" pre release version,11, june 2021

Disclosure of Invention

Problems to be solved by the invention

Non-patent document 1 describes that a protective column is attached to a separation column using an insertion tube in the following procedure. First, a protective column is inserted from one end of the insertion tube, and a separation column is inserted from the other end. Then, ferrules (ferrules) are respectively disposed at both ends of the insertion tube. Finally, nuts are respectively installed at the outer sides of the ferrules at both ends and the ferrules are pressed, thereby fixing the protection column and the separation column inside the insertion tube. As described above, in order to connect the protection column described in non-patent document 1 to the separation column, it is necessary to perform 3 steps of operation steps, which is time-consuming and labor-consuming. If the connection state between the guard column and the separation column is not complete, leakage of the carrier gas and the control compound occurs, and errors occur in the measurement result. A person who measures the content of the control compound for the purpose of inspecting the resin product is not necessarily a person skilled in performing such an operation, and therefore, a technique capable of more easily suppressing degradation of the separation column has been demanded. Further, non-patent document 1 uses a metal insertion tube. As described in non-patent document 3, the above-mentioned control compound contains a compound having high reactivity that reacts with a metal, and if there is a gap in the connection portion between the guard column and the separation column inserted into the insertion tube, the content of the control compound cannot be accurately measured when the control compound having high reactivity adsorbs to the metal constituting the insertion tube and is decomposed further.

The case where the pyrolysis device is used to gasify the control compound will be described here as an example, but the same problems as described above are also found when the pyrolysis device is used in addition to the pyrolysis device to gasify the phthalate and brominated flame retardant compounds for chromatographic analysis.

The present invention aims to provide a method for accurately measuring phthalic acid esters and brominated flame retardant compounds which are easily adsorbed and decomposed, while suppressing deterioration of a separation column without requiring complicated operations, and a column for gas chromatography used in the implementation of the method.

Solution for solving the problem

In the method for measuring a phthalate and a brominated flame retardant compound according to the present invention for solving the above-mentioned problems,

heating a sample containing a target compound belonging to at least one of phthalic acid esters, polybrominated diphenyl groups, and polybrominated diphenyl ether groups to gasify the target compound contained in the sample,

the analysis column is temperature-regulated to a temperature lower than the highest temperature at which the target compound is gasified, and comprises: a separation column provided with a stationary phase for separating the target compound inside; and a protection column integrally provided with the separation column at an inlet side of the separation column without using a connection member,

Introducing the vaporized target compound into the analytical column,

detecting the target compound flowing out from the separation column.

Another aspect of the present invention, which has been made to solve the above-described problems, is a gas chromatography column for use in carrying out a method for measuring a phthalate type and a brominated flame retardant compound, comprising:

a separation column provided with a stationary phase for separating a subject compound belonging to at least one of phthalic acid esters, polybrominated diphenyl groups, and polybrominated diphenyl ether groups; and

and a guard column integrally provided with the separation column at an inlet side of the separation column without using a connection member.

ADVANTAGEOUS EFFECTS OF INVENTION

In the present invention, an analytical column is used, which has: a column provided with a stationary phase for separating a subject compound belonging to at least one of phthalate esters, polybrominated biphenyls, and polybrominated diphenyl ethers; and a protection column provided integrally with the separation column at an inlet side of the separation column. In the present invention, the separation column and the protection column are integrally formed without using a connecting member, and therefore, there is no need for an operation of connecting them, and there is no case where carrier gas leaks from a connecting portion between the both, and the target compound or the target compound is adsorbed to the connecting member and decomposed. Therefore, deterioration of the separation column can be suppressed without requiring a complicated operation, and phthalate esters or brominated flame retardant compounds which are easily attached to and decomposed by the separation column can be accurately measured.

Drawings

FIG. 1 is a schematic diagram of the key parts of a pyrolyzer-gas chromatograph/mass spectrometer, including one embodiment of a gas chromatograph column according to the present invention, used in one embodiment of a method for measuring phthalic acid esters and brominated flame retardant compounds according to the present invention.

Fig. 2 is a diagram showing the structure of the column in this embodiment.

Fig. 3 is a graph showing the relationship between the length of the guard column and the flow rate of the carrier gas when the flow rate of the carrier gas is constant.

FIG. 4 shows the measurement conditions of the phthalate and brominated flame retardant compounds in this example.

Fig. 5 is an example of a relative sensitivity coefficient table in the present embodiment.

FIG. 6 is a flow chart showing the steps in one embodiment of a method for determining phthalate esters and brominated flame retardant compounds of the invention.

FIG. 7 is a flow chart showing the steps in another example of the method for measuring phthalic acid esters and brominated flame retardant compounds of the invention.

FIG. 8 shows the results of measurement for confirming the effect obtained by the method and column for measuring phthalic acid esters and brominated flame retardant compounds of this example.

Detailed Description

An example of a method for measuring phthalate esters and brominated flame retardant compounds and a gas chromatography column according to the present invention will be described below with reference to the accompanying drawings. In this example, by using a pyrolyzer-gas chromatograph mass spectrometer (Py-GC-MS), a flame retardant compound was prepared against phthalic acid esters and polybrominated biphenyls (polybrominated biphenyls, PBBs, molecular formula: C ₁₂ H _(10-n) Br _n (1.ltoreq.n.ltoreq.10)) and polybrominated diphenyl ether groups (polybrominated diphenyl ethers, PBDEs, molecular formula: c (C) ₁₂ H _(10-m) Br _m O (1.ltoreq.m.ltoreq.10)) is quantified, and the sample to be analyzed is screened. Hereinafter, these compounds are collectively referred to as regulatory compounds. The sample to be analyzed in this embodiment is a resin product or the like to be subjected to the RoHS instruction.

Composition of Py-GC-MS

Fig. 1 shows the key part constitution of a pyrolyzer-gas chromatograph/mass spectrometer (Py-GC-MS) 1 used in the measurement method of the control compound of the present embodiment.

The Py-GC-MS1 is basically constituted by a gas chromatograph 10, a mass spectrometer 20, and a control/processing unit 30. The gas chromatograph 10 includes: a sample vaporization chamber 11, a pyrolyzer 12 provided in the sample vaporization chamber 11, a carrier gas flow path 13 connected to the sample vaporization chamber, and a column 14 connected to an outlet of the sample vaporization chamber 11. The column 14 is housed inside a column oven 15. The pyrolyzer 12 and the column 14 in the column oven 15 are heated to a predetermined temperature by heating means not shown.

Fig. 2 shows the structure of the column 14 (corresponding to the analytical column in the present invention) used in the present embodiment. The column 14 is composed of a protection column 141 and a separation column 142. The protection column 141 is provided integrally with the separation column 142 on the sample injection port side of the separation column 142 without a joint. The guard column 141 and the separation column 142 are both capillary tubes made of fused silica having an inner diameter of 0.25mm, and a stationary phase (liquid phase) for desorbing the sample component by interaction with the control compound is provided only on the inner wall surface of the separation column 142. In the separation column 142 of this example, 100% dimethylpolysiloxane was used as the stationary phase at a membrane thickness of 0.1. Mu.m. As stationary phase for determining the management compound, stationary phases other than dimethylpolysiloxane may be used. In view of the fact that the control compound in this embodiment is a compound having a large polarity, it is preferable to use a nonpolar substance as the stationary phase at a film thickness of 1.0 μm or less. Among these, since it is necessary to desorb each controlling compound from the stationary phase by causing a certain degree of interaction between them, the film thickness is preferably set to 0.05 μm or more.

Conventionally used guard columns include guard columns having a stationary phase provided therein. By providing the stationary phase inside the guard column, the impurities are easily trapped and hardly reach the separation column, and therefore, the separation column is hardly contaminated. However, on the other hand, since the inclusion is trapped together with the target compound by the stationary phase of the guard column, the peak tends to be smeared when the target compound is measured. In this embodiment, a guard column 141 without stationary phase is used in order to prevent tailing of the peak of the management compound.

The length of the protection column 141 of the present embodiment is 2m, and the length of the separation column 142 is 15m. The guard column 141 serves to prevent the separation column 142 from being contaminated with substances other than the management compound (pyrolyzed matter of the resin, inclusion compound, etc.) released when the resin sample is heated by the pyrolyzer 12. Since the heating temperature of the column oven 15 for heating the column 14 is lower than the heating temperature in the pyrolyzer 12, the substances released from the pyrolyzer 12 are slowly cooled and attached to the inner wall surface of the protection column 141. If the guard column 141 is shorter than 50cm, these substances easily enter the separation column 142. On the other hand, if the guard column 141 is longer than 4m, the flow rate of the carrier gas must be greatly increased to set the same linear velocity as in the case where the guard column is not used, and the consumption of the carrier gas is greatly increased. Therefore, the length of the guard post 141 is preferably 50cm or more and 4m or less.

Fig. 3 shows the relationship between the carrier gas flow rate and the guard column length required for using a separation column having a length of 15m and an inner diameter of 0.25mm and setting the linear velocity to 52.1cm/sec, as in the present example. If the length of the guard column 141 is 4m or less, the increase in the carrier gas flow rate can be suppressed to 30% or less of the flow rate when the guard column 141 is not used. If the guard column 141 of 2m is used as in the present embodiment, the carrier gas flow rate is increased by only 10%, and the same linear velocity as in the case where the guard column 141 is not used can be set. The carrier gas flow value itself also depends on the inner diameter of the column, the length of the separation column, and in most cases the carrier gas flow and guard column length exhibit the same relationship as in fig. 3. Therefore, the length of the guard column is preferably 50cm or more and 4m or less.

The mass spectrometer 20 includes an electron ionization source 22, an ion lens 23, a quadrupole mass filter 24, and an ion detector 25 in a vacuum chamber 21. The sample components separated with time in the column 14 are sequentially introduced into the electron ionization source 22, and are ionized by irradiation with hot electrons released from a hot filament (not shown).

The control/processing section 30 has a storage section 31. The storage unit 31 stores a method file used for measuring the control compound. The method file is a file in which measurement conditions of the control compound are described. The measurement conditions include: information such as the temperature of the pyrolyzer 12, the temperature of the separation column 142 (the temperature of the column oven 15), the kind and flow rate of the carrier gas, and two kinds of ions (quantitative ions and confirmatory ions) each characterizing phthalate esters, PBBs, and PBDEs as the control compounds. Fig. 4 shows an example of measurement conditions. In FIG. 4, 3 ions (1 quantitative ion and 2 confirmatory ions) are shown for phthalic acid esters, and 2 ions (1 quantitative ion and 1 confirmatory ion) are shown for PBBs and PBDEs. The quantitative ion is used to quantify the compound according to the peak area (or height) of the quantitative ion. The confirming ion is used to determine (identify) it as the compound based on the ratio of the height of the peak area of the quantitative ion to the peak area of the confirming ion being within a predetermined range. Depending on the measurement sample, the mass-to-charge ratio of either one of these quantitative ions and the confirmed ions may be close to that of the ions generated from the inclusions contained in the sample, and the ions of this mass-to-charge ratio may not be used. Therefore, the storage unit 31 also stores information on the mass-to-charge ratio of 1 or more preliminary ions for each compound.

The relative response coefficient database 311 is stored in the storage unit 31. The relative response coefficient database 311 refers to: the regulatory compound other than the reference compound, i.e., the reference compound, is made to correspond to a database of 1 or more predetermined reference compounds contained in the regulatory compound. In the relative response sensitivity coefficient database 311, the ratio (relative response coefficient RRF) of the detection sensitivity of the reference compound to the detection sensitivity of the reference compound is made into a database. An example of the relative response coefficient table associated with the PBBs and the PBDEs is shown in fig. 5. The relative response coefficient database is similarly stored for phthalic acid esters (for example, non-patent document 4). The relative response coefficient database 311 is used when "2-1" is used for screening of a regulatory compound using the relative response coefficient database "(described later), and when" 2-2 "is used for screening of a regulatory compound using a standard curve of each of the regulatory compounds" (described later), it is not necessary to store the relative response coefficient database 311 in the storage unit 31 in advance.

Relative response coefficient RRF of reference compound a to reference compound x _a/x Represented by the following formula (1).

RRF _a/x ＝RF _a /RF _x …(1)

Here, rfa and RFx are response coefficients of the reference compound a and the reference compound x, respectively.

Response coefficient RF of reference Compound a _a Represented by the following formula (2). The following numerical expression is the same not only for the reference compound a but also for the reference compound x.

RF _a ＝A _a /m _a …(2)

Here, A _a And m _a Peak area and weight (mg) of reference compound a in the mass spectrum, respectively. In addition, the weight m of the reference compound a _a Represented by the following formula (3).

m _a ＝M×C _a …(3)

Here, M and C _a The weight (kg) of the standard sample and the concentration (mg/kg) of the reference compound a contained in the standard sample are respectively.

The control/processing unit 30 includes, as functional blocks, a reference compound determination unit 32, a standard sample measurement unit 33, an analysis target sample measurement unit 34, a reference compound quantification unit 35, a reference compound quantification unit 36, and a screening unit 37. The control/processing unit 30 is a general personal computer, and executes a pre-installed analysis sample measurement program by a processor to realize the above-described functional blocks. The control/processing unit 30 is connected to an input unit 4 for a user to perform an input operation and a display unit 5 for displaying various information. Of the above functional blocks, the standard compound determination unit 32 and the reference compound quantification unit 36 (functional blocks shown by broken lines in fig. 1) are functional blocks for "2-1" screening of the regulatory compounds using the relative response coefficient database (described later), and in the case of "2-2" screening of the regulatory compounds using standard curves of the respective regulatory compounds (described later), the control/processing unit 30 may be provided with the standard sample measurement unit 33, the analysis target sample measurement unit 34, the standard compound quantification unit (quantification unit) 35, and the screening unit 37 (functional blocks shown by solid lines in fig. 1).

2. Screening step of the control Compounds

Next, a step of screening the analysis target sample will be described. In the Py-GC-MS1 of this example, both screening of the regulatory compound using the relative response coefficient database and screening of the regulatory compound using the standard curve of each of the regulatory compounds can be performed.

2-1 screening of management compounds Using a relative response coefficient database

The steps of screening for regulatory compounds using the relative response coefficient database are described with reference to the flow chart shown in fig. 6.

When the user instructs screening of the control compound, the reference compound determining unit 32 reads the relative response coefficient database 311 from the storage unit 31, and displays a relative response coefficient table (fig. 5) described therein on the display unit 5. The user confirms the reaction, and changes the correspondence between the reference compound and the reference compound as needed. For example, in the case where it is difficult to obtain a standard sample containing a selected reference compound in the relative response coefficient table, the compound may be deleted from the reference compound or another compound may be set as the reference compound. When the user ends the confirmation of the reference compound, the reference compound is determined (step 1).

Next, resin samples each containing a known amount of the reference compound were prepared as standard samples, and the container containing the standard samples was placed in a pyrolyzer to instruct the start of measurement.

When the start of measurement is instructed, the standard sample measurement unit 33 measures the standard sample in accordance with the measurement conditions (the method related to the measurement of the reference compound) described in the method file corresponding to the relative response coefficient database 311 stored in the storage unit 31 (step 2). In this example, according to the measurement conditions shown in FIG. 3, first, the temperature of the pyrolyzer 12 was raised from 200℃at a rate of 20℃per minute. After reaching 300 ℃, the temperature was raised at a rate of 5 ℃/min, and the temperature was maintained at 340 ℃ for 1 minute. Thereby, the control compound contained in the standard sample is gasified (step 21). The vaporized control compound is introduced into analytical column 14 as a function of the carrier gas stream. When the heating of the standard sample by the pyrolyzer 12 is completed, the display unit 5 displays that the heating of the standard sample measuring unit 33 is completed (or a notification is made by sound or the like), and instructs the user to take out the container.

During the heating of the pyrolyzer 12, the sample injection portion of the sample vaporization chamber 11 of the gas chromatograph is maintained at 300 ℃, and the analytical column 14 is maintained at 80 ℃ (step 22). Accordingly, each substance containing the resin decomposed product obtained by gasifying the standard sample in the pyrolyzer 12 is gradually cooled and introduced into the analysis column 14 (step 23). The resin decomposed product introduced into the analysis column 14 is attached to the inner wall inside the protection column 141 provided on the inlet side of the analysis column 14. The management compound attaches to the inner wall of the guard column 141 or primarily to and attaches to the inlet of the separation column 142.

When the user takes out the container from the pyrolyzer 12, the standard sample measurement unit 33 starts heating the column oven 15. In this example, the temperature was raised from 80℃at a rate of 20℃per minute, and maintained at 320℃for 4 minutes. The control compounds attached to the inlet of the separation column 142 sequentially enter the inside of the separation column 142 from the substances that reach the vaporization temperature of the respective compounds, and are desorbed from the stationary phase 1421 of the separation column 142 by the action with the stationary phase 1421, and enter the separation column 142 to flow out. The compounds flowing out of the separation column 142 are sequentially introduced into the electron ionization source 22.

Ions generated in the electron ionization source 22 are converged near the center axis (ion optical axis C) in the flight direction by the ion lens 23, then enter the quadrupole mass filter 24, are separated according to the mass-to-charge ratio, and are detected by the ion detector 25 (step 24). The output signals from the ion detector 25 are sequentially supplied to the storage unit 31 and stored.

In measurement of a standard sample, scanning measurement and Selective Ion Monitoring (SIM) measurement are repeatedly performed by the mass spectrometry section 20. Specifically, the following measurements were set to 1 set, and the measurements were repeated: scanning measurement, in which the mass-to-charge ratio of ions passing through the quadrupole mass filter 24 is scanned over a predetermined range (for example, a range of 50 to 1000 m/z); and a SIM measurement for each m/z set in advance, wherein the mass-to-charge ratio of the ions passing through the quadrupole mass filter 24 is fixed for a predetermined time at the mass-to-charge ratio of the quantitative ions or the confirmed ions of each compound. The scanning measurement is not essential, and only the SIM measurement may be repeated.

In addition, n-alkane samples were measured in addition to the standard samples. The n-alkane sample is a standard sample containing a plurality of compounds having different hydrocarbon chain lengths from each other, and is used to obtain a retention index based on the retention time of each compound. As described in non-patent document 4, the retention index Ix of the compound x is represented by the following formula (4).

I _x ＝100(C _n+i -C _n ){(t _x -t _n )/(t _n+i -t _n )}+100C _n …(4)

Here, C _n 、C _n+i The number of carbon atoms of n-alkanes having a retention time between the compounds and a retention time between the compounds; t is t _x Retention time for compound x; t is t _n 、t _n+i To sandwich the retention of the compoundThe retention time of n-alkanes is located before and after the retention time. In the case where the retention index of each of the control compounds is obtained in advance, the measurement of the n-alkane sample is omitted, and the n-alkane sample is measured only when the sample to be analyzed is measured, and the retention time of each of the control compounds can be estimated from the retention time of each of the compounds contained in the n-alkane sample and the value of the retention index of the control compound obtained in advance.

After the measurement of the standard sample is completed, the standard sample measurement unit 33 creates a standard curve corresponding to each of the reference compounds (step 3). Here, only 1 standard sample was measured, and 1 standard curve was prepared. When the amount of the reference compound and the measurement intensity are in a nonlinear relationship, a plurality of standard samples having different amounts of the reference compound can be measured, and a standard curve can be prepared from 2 or more measurement points.

After creating the standard curve of the reference compound, the user sets up the sample to be analyzed, and instructs the start of measurement, and the sample measurement unit 34 measures the sample to be analyzed using the measurement conditions described in the method file corresponding to the relative response coefficient database 311 (step 4). Specifically, according to the measurement conditions shown in fig. 3, first, the temperature of the pyrolyzer 12 is raised from 200 ℃ at a rate of 20 ℃/min. After reaching 300 ℃, the temperature was raised at a rate of 5 ℃/min, and the temperature was maintained at 340 ℃ for 1 minute. Thereby, the control compound contained in the standard sample is gasified (step 41). The vaporized control compound is introduced into analytical column 14 as a function of the carrier gas stream. When the heating of the standard sample by the pyrolyzer 12 is completed, the display unit 5 displays that the heating of the standard sample measuring unit 33 is completed (or a notification is made by sound or the like), and instructs the user to take out the container.

During the heating of the pyrolyzer 12, the sample injection portion of the sample vaporization chamber 11 of the gas chromatograph is maintained at 300 ℃, and the analytical column 14 is maintained at 80 ℃ (step 42). Accordingly, each substance including the resin decomposed product obtained by gasifying the analysis target sample in the pyrolyzer 12 is gradually cooled and introduced into the analysis column 14 (step 43). The resin decomposed product introduced into the analysis column 14 adheres to the inner wall of the guard column 141 provided on the inlet side of the analysis column 14. The management compound attaches to the inner wall of the guard column 141 or primarily to and attaches to the inlet of the separation column 142.

When the user takes out the container from the pyrolyzer 12, the standard sample measurement unit 33 starts heating the column oven 15. In this example, the temperature was raised from 80℃at a rate of 20℃per minute, and maintained at 320℃for 4 minutes. The control compound attached to the inlet of the guard column 141 or the separation column 142 sequentially enters the inside of the separation column 142 from the material that reaches the vaporization temperature of each compound, and then flows out while being desorbed from the stationary phase 1421 of the separation column 142 by the action with the stationary phase 1421 of the separation column 142. The compounds flowing out of the separation column 142 are sequentially subjected to mass spectrometry in the mass spectrometry section 20, and detected in the ion detector 25 (step 44).

In the case where the retention time of each target compound is predicted based on the retention index, the n-alkane sample may be measured separately from the measurement of the sample to be analyzed. In the measurement of the sample to be analyzed, the scanning measurement is not essential, and only the SIM measurement may be performed. However, when a large peak is observed in addition to the compound to be measured after the total ion current chromatogram is prepared by performing the scanning measurement in advance, the compound corresponding to the peak can be identified by analyzing the mass spectrum obtained during the retention time of the peak.

When the measurement of the sample to be analyzed is completed, the standard compound quantifying section 35 determines the peak of the mass spectrum of the quantified ion and the confirmed ion from the retention index of each standard compound or the predicted retention time calculated based on the retention index and the measurement data of the n-alkane. Then, the peak area of the quantitative ion and the peak area of the confirmed ion are determined to be within a predetermined range, and the quantitative value is obtained by comparing the peak area of the quantitative ion with the standard curve of the reference compound (step 5).

When a quantitative value of the reference compound can be obtained, the reference compound quantitative section 36 determines a quantitative ion of each reference compound and a peak of a mass spectrum of the confirmed ion based on a retention time of each reference compound or a predicted retention time calculated based on a retention index of each reference compound and measurement data of n-alkane. The peak area of the quantitative ion and the peak area of the confirmed ion are within a predetermined range. Further, a quantitative value of each reference compound is obtained from the amount of the reference compound contained in the standard sample, the peak area of the quantitative ion of the reference compound detected by measuring the standard sample, the peak area of the quantitative ion of the reference compound, and the relative response coefficient (step 6).

When quantitative values are obtained for the reference compound and the reference compound, the screening unit 37 compares these quantitative values with a predetermined threshold value, and screens out the sample to be analyzed. In this example, it was determined whether the quantitative value of DEHP, BBP, DBP, DIBP contained in the sample to be analyzed was within.+ -.50% of the reference value and whether the total amount of PBBs and PBDEs were within.+ -.70% of the reference value, based on the reference value (DEHP amount, BBP amount, DBP amount, DIBP amount, total amount of PBBs and total amount of PBDEs were each 1000mg/kg or less) in the RoHS instruction (step 7).

Specifically, the following determination criteria described in non-patent document 5, for example, can be used. When the quantitative values of DEHP, BBP, DBP and DIBP contained in the sample to be analyzed are 500mg/kg or less, and when the total value of the quantitative values of PBBs and PBDEs is 300mg/kg or less, it is determined that the sample to be analyzed satisfies the criterion of the RoHS instruction. Further, when the quantitative values of DEHP, BBP, DBP and DIBP were 1500mg/kg or more and when either one of the total of the quantitative values of PBBs and PBDEs was 1700mg/kg or more, it was determined that the analysis target sample did not satisfy the criterion of the RoHS instruction. Further, when the quantitative values of DEHP, BBP, DBP and DIBP are 300mg/kg to 1500mg/kg (excluding the case where either one is 1500mg/kg or more), and when either one of the total quantitative values of PBBs and PBDEs is 300mg/kg to 1700mg/kg (excluding the case where either one is 1700mg/kg or more), the determination is made to retain, and the analysis target sample is analyzed in detail by another method, so that the quantitative value is calculated more closely.

2-2 screening of regulatory compounds using a standard curve for each of the regulatory compounds

The steps of screening for regulatory compounds using the standard curves for each of the regulatory compounds are described with reference to the flow chart shown in fig. 7. The same procedure as for screening of the control compound using the relative response coefficient database is omitted as appropriate.

When the user sets a container containing a standard sample, which is a resin sample containing all the known amounts of the control compounds, in the pyrolyzer and instructs the start of measurement, the standard sample measurement unit 33 measures the standard sample in accordance with the measurement conditions described in the method file stored in the storage unit 31 (step 11). The steps described in the measurement of the standard sample (steps 21 to 24) are the same as those in the case of using the relative response coefficient database (except for the point of measuring all the regulatory compounds), and therefore, detailed description thereof is omitted.

After the measurement of the standard sample is completed, the standard sample measurement unit 33 creates a standard curve for each of the control compounds (step 12). Here, only 1 standard sample was measured to prepare 1 standard curve. When the amount of the control compound and the measured intensity are in a nonlinear relationship, a plurality of standard samples having different contents can be measured for the control compound, and a standard curve can be prepared from 2 or more measurement points.

After creating the standard curve of each controlling compound, the user sets up the sample to be analyzed and instructs the start of measurement, and the sample measurement unit 34 measures the sample to be analyzed using the measurement conditions described in the method file stored in the storage unit 31, similarly to the case of measuring the standard sample (step 13). The steps described in the measurement of the sample to be analyzed (steps 41 to 44) are also similar to those in the case of using the relative response coefficient database, and therefore, detailed description thereof is omitted.

When the measurement of the sample to be analyzed is completed, the reference compound quantifying section 35 determines the quantified ions of each of the control compounds and confirms the peaks of the mass spectrum of the ions based on the retention time of each of the control compounds obtained when the standard sample is measured. The quantitative value is obtained by comparing the peak area of the quantitative ion with the standard curve of each control compound, and confirming that the peak area of the quantitative ion and the peak area of the confirmed ion are within a predetermined range (step 14).

When quantitative values are obtained for the respective control compounds, the screening unit 37 compares these quantitative values with a predetermined threshold value, and screens out the analysis target sample. Here, as well, based on the reference value (the amount of DEHP, the amount of BBP, the amount of DBP, the amount of DIBP, the total amount of PBBs, and the total amount of PBDEs are all 1000mg/kg or less) in the RoHS instruction, it is determined whether the quantitative value of DEHP, BBP, DBP, DIBP included in the analysis target sample is within ±50% of the reference value, and whether the total amount of PBBs and PBDEs is within ±70% of the reference value (step 15).

As such, in the present embodiment, the column 14 is used, which has: a separation column 142 for separating a stationary phase of a management compound, and a guard column 141 integrally provided with the separation column 142 at an inlet side of the separation column 142 are provided. The separation column 142 is integrally formed with the protection column 141 without using a connecting member, and therefore, an operation of connecting the two by using a member such as a nut or a ferrule is not required as in the case of using a conventional general protection column. In addition, the carrier gas and the control compound do not leak from the connection portion between the two, and there is no case where the control compound is adsorbed and decomposed by contacting the connection member. Therefore, the degradation of the separation column 142 can be suppressed without requiring a complicated operation, and the control compound that easily adheres to and decomposes the separation column 142 can be accurately measured.

The measurement method of the above-described embodiment and the experimental result of confirming the effect of preventing contamination of the separation column 142 by using the column 14 are explained. In this experiment, a resin standard sample for measuring phthalic acid esters (P/N: 225-31003-91, manufactured by Shimadzu corporation) containing 100mg/kg of DBP was repeatedly measured, and the shape (symmetry) of the peak of the mass spectrum obtained at each measurement was confirmed. The shape of a peak is represented by an index called a symmetry coefficient, and the larger the tail of the peak, the larger the value of the symmetry coefficient. In general, if the symmetry coefficient exceeds 2.5, it is determined that the column is contaminated, and replacement of the column is performed.

Fig. 8 shows the results of measurement (measurement conditions are the same as those of the above-described examples, fig. 4) using the column 14 of the above-described examples. Fig. 8 is a graph obtained by plotting the change of the symmetry coefficient with respect to the number of measurements. In the column without the guard column, the symmetry coefficient is usually more than 2.5 due to 300 to 400 measurements, whereas the symmetry coefficient is less than 2.5 even if 700 or more measurements are performed on the column 14 of the above example. In other words, in contrast to the conventional case where the column 14 of this example is used, the column replacement operation is not required for at least 700 times of measurement, and the durability of the column 14 is improved by a factor of 2 or more.

The above-described embodiments are examples, and can be modified as appropriate according to the gist of the present invention. In the above examples, the analysis target sample was screened by using Py-GC-MS1 and thermally desorbing the control compound by Py/TD-GC/MS method, but the analysis target sample may also be screened by pyrolyzing the control compound by Py-GC/MS method. The apparatus configuration in performing the Py-GC/MS method was the same as that of the above example, and the sample heating temperature by the pyrolyzer was different. Alternatively, the control compound may be gasified from the sample by using a thermal desorption device which does not use a thermal pyrolyzer. In any of these configurations, since the highest temperature at the time of heating the resin sample is higher than the heating temperature of the separation column in order to gasify the target compound contained in the resin sample, substances other than the control compound (decomposed product of the resin, and inclusion compound) are introduced into the analysis column 14 as in the case of the above-described embodiment, and thus contamination of the separation column 142 can be prevented by providing the protection column 141 as in the above-described embodiment. Further, since the protection column 141 and the separation column 142 are integrally formed without using a connecting tool such as a nut or a ferrule, it is possible to accurately measure a compound that is easily adsorbed and decomposed, such as a phthalate ester or a flame retardant brominated compound.

In the above-described example, the mass spectrometry was performed on each compound flowing out from the column 14, but each compound may be detected by a method other than the mass spectrometry. As such a detector, for example, a hydrogen Flame Ionization Detector (FID), a thermal ionization detector (FTD), a Flame Photometric Detector (FPD), an Electron Capture Detector (ECD), a chemiluminescent sulfur detector (SCD), a Thermal Conductivity Detector (TCD), a barrier discharge ionization detector (BID), or the like can also be used.

Mode for carrying out the invention

Those skilled in the art will appreciate that the various illustrative embodiments described above are specific examples of the manner described below.

(item 1)

In the method for measuring a phthalate and a brominated flame retardant compound according to one embodiment of the present invention,

heating a sample containing a target compound belonging to at least one of phthalic acid esters, polybrominated diphenyl groups and polybrominated diphenyl ether groups to gasify the target compound contained in the sample,

Introducing the vaporized target compound into the analytical column,

detecting the target compound flowing out from the separation column.

(item 8)

Another embodiment of the present invention is a gas chromatography column used for carrying out a method for measuring phthalic acid esters and brominated flame retardant compounds, comprising:

The method for measuring a phthalate and a brominated flame retardant compound according to item 1, wherein the gas chromatography column according to item 8 is used. In this gas chromatography column, the separation column and the protection column are integrally formed without using a connecting member, and therefore, there is no need for an operation of connecting them, and there is no case where the target compound leaks from the connecting portion between the both or the target compound is adsorbed to the connecting member and decomposed. Therefore, deterioration of the separation column can be suppressed without requiring a complicated operation, and the phthalate esters or brominated flame retardant compounds which are easily attached to and decomposed by the separation column can be accurately measured.

(item 2)

In the method for measuring a phthalic acid ester and a brominated flame retardant compound according to item 1,

the target compound is gasified in a pyrolyzer.

In the method for measuring a phthalic acid ester and a brominated flame retardant compound according to item 2, the temperature at which the sample is heated in the pyrolyzer is appropriately set, so that a method of vaporizing the target compound by pyrolysis and a method of vaporizing the target compound by thermal desorption can be appropriately used.

(item 3)

The method for measuring a phthalic acid ester or a brominated flame retardant compound according to item 1 or 2,

among the analytical columns, only the separation column is provided with a stationary phase.

Among conventionally used guard columns, there is a guard column having a stationary phase (liquid phase) provided therein. By providing the stationary phase inside the guard column, the impurities are easily trapped and hardly reach the separation column, and therefore the separation column is not easily contaminated. On the other hand, the inclusion trapped in the stationary phase of the guard column flows out, and the peak tends to be smeared when the compound to be measured is measured. In the method for measuring a phthalate and a brominated flame retardant compound according to item 3, since an analytical column having a stationary phase only in a separation column is used, tailing of peaks in a chromatogram can be suppressed, and the content of a controlling compound can be accurately measured.

(item 4)

The method for measuring a phthalate and a brominated flame retardant compound according to any of items 1 to 3,

the length of the guard column is 50cm or more and 4m or less.

In the method for measuring a phthalate and a brominated flame retardant compound according to item 4, the use of a protective column having a length of 50cm or more can prevent impurities such as resin decomposed products from entering the separation column and contaminating the separation column. Further, by setting the guard column to 4m or less, the carrier gas flow rate can be increased by only about 3 as compared with the case where the guard column is not used, and the target compound can be measured at the same linear velocity.

(item 5)

The method for measuring a phthalate and a brominated flame retardant compound according to any of items 1 to 4,

the length of the separation column is 10m to 30 m.

In the method for measuring a phthalic acid ester and a brominated flame retardant compound according to item 5, the control compound contained in the sample can be sufficiently separated by using a separation column having a length of 10m or more. Further, since the length of the separation column is 30m or less, the measurement time is not extremely long.

(item 6)

The method for measuring a phthalate and a brominated flame retardant compound according to any of items 1 to 5,

The target compound flowing out of the separation column is detected by mass spectrometry.

The resin sample containing the phthalate type or brominated flame retardant compound contains various inclusions in addition to the target compound. In addition, when the target compound is gasified, the resin decomposed product also enters the column of the gas chromatograph. In the method for measuring a phthalate and a brominated flame retardant compound according to item 6, since each compound flowing out from the separation column is detected by mass spectrometry, even when an inclusion eluted together with the target compound is present, the inclusion can be found with high accuracy, and the content of the target compound can be accurately measured.

(item 7)

The method for measuring a phthalate and a brominated flame retardant compound according to any of items 1 to 6, wherein the sample is further selected based on whether or not the content of the target compound is within a predetermined range.

The method for measuring a phthalate and a brominated flame retardant compound according to any of items 1 to 6 can be suitably used for screening the sample according to whether or not the content of the target compound is within a predetermined range as described in item 7. In particular, by using an analytical column having the protective column and the separation column of the lengths described in the 4 th and 5 th items, a sample to be analyzed can be efficiently screened.

Description of the reference numerals

1 … thermal desorption-gas chromatography/mass spectrometry analysis device

10 … gas chromatography part

11 … sample gasification chamber

12 … pyrolyzer

13 … Carrier gas flow passage

14 … column (analytical column)

141 … protective column

142 … separation column

1421 … stationary phase

15 … column oven

20 … Mass Spectrometry section

21 … vacuum chamber

22 … electron ionization source

23 … ion lens

24 … quadrupole mass filter

25 … ion detector

30 … control/processing section

31 … storage part

311 … relative response coefficient database

32 … reference compound determination unit

33 … Standard sample measuring section

34 … analysis target sample measuring section

35 … reference Compound quantitative part

36 … reference Compound quantitative part

37 … screening part

4 … input part

5 … display part

Claims

1. A method for measuring a phthalate and a brominated flame retardant compound, wherein a sample containing a target compound belonging to at least one of phthalate, polybrominated diphenyl groups and polybrominated diphenyl ether groups is heated to gasify the target compound contained in the sample,

and (c) adjusting the temperature of an analytical column to a temperature lower than the highest temperature at which the target compound is gasified, the analytical column comprising: a separation column provided inside with a stationary phase for separating the object compound; and a protection column integrally provided with the separation column at an inlet side of the separation column without using a connection member,

Introducing the vaporized object compound into the analytical column,

detecting the target compound flowing out of the separation column.

2. The method for measuring a phthalate and brominated flame retardant compound according to claim 1 wherein said object compound is gasified in a pyrolyzer.

3. The method for measuring phthalic acid esters and brominated flame retardant compounds according to claim 1, wherein a stationary phase is provided only in the separation column among the analytical columns.

4. The method for measuring a phthalate and a brominated flame retardant compound according to claim 1, wherein the length of said guard column is 50cm or more and 4m or less.

5. The method for measuring a phthalate and a brominated flame retardant compound according to claim 1, wherein the separation column has a length of 10m or more and 30m or less.

6. The method for measuring a phthalate and a brominated flame retardant compound according to claim 1, wherein a target compound flowing out of said separation column is detected by mass spectrometry.

7. The method for measuring a phthalate and a brominated flame retardant compound according to claim 1, wherein said sample is further selected according to whether or not the content of said object compound is within a predetermined range.

8. A gas chromatography column is provided with:

a separation column provided with a stationary phase for separating a subject compound belonging to at least one of phthalic acid esters, polybrominated biphenyls, and polybrominated diphenyl ethers; and