JPH11344479A - Method and apparatus for simultaneously measuring multiple components - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple component simultaneous measuring method capable of easily analyzing more trace components at the same time. SOLUTION: An on-line pretreatment process introducing a soln. to be measured containing objective components into a pretreatment column to remove impurity components eluted more rapidly than objective components (steps 100, 102) and simultaneously eluting respective components developed in the column by a back flash method (step 104), a chemical treatment process for chemically treating the soln. to be measured obtained by the back flash method so as to introduce the same into a chemical treatment column to elute the objective components at the impurity eluting position (step 106), a separation process introducing the soln. to be measured obtained in the process (step 106) into a separation column (step 8), and an objective component detection process (step 110) detecting the objective components separated in the process (step 108), are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for simultaneous measurement of multiple components, and more particularly to an improvement in a method and an apparatus for measurement using liquid chromatography.

[0002]

2. Description of the Related Art For example, it has been revealed that some polycyclic aromatic hydrocarbons and their nitro derivatives present in the environment such as the atmosphere have carcinogenicity and mutagenicity, and are increasing around cities and highways. It is suspected to be associated with a trending lung cancer. One of these major sources is automotive exhaust,
In particular, the effects of diesel engines are considered. However, since such substances are present in a very small amount and are difficult to detect, and particularly the kinetics in the atmosphere have not been clarified, a highly sensitive analysis method for these substances has been demanded.

As a conventional method for measuring nitropolycyclic aromatic hydrocarbons (nitroarenes), nitroarenes having no fluorescence are reduced to aminopolycyclic aromatic hydrocarbons having strong fluorescence (aminoarenes). A method of detecting fluorescence using high performance liquid chromatography is mainly used. Fig. 1 shows a conventional nitroarene measuring device.
The one shown in (a) is used (see, “Automobile Research, Vol. 7, No. 4, Research on Measurement Method of Nitropolycyclic Aromatic Hydrocarbons in Diesel Exhaust Particles” published in April, 1985).

[0004] In the figure, in a nitroarene measuring apparatus, a liquid sending pump 12 sends an eluent from an eluent storage tank 10. After the liquid to be measured containing nitroarene is injected into the eluate from the sample injection part 14, the flow path switching valves 8 and 9 are appropriately switched, and measurement is performed by switching to any of the following three flow paths. I have. That is, as shown in FIG. 2 (b), when analysis is performed, the liquid to be measured is set in advance in the flow channel 1, the liquid to be measured is separated in the first column 16, and then introduced into the reduction column 18 to be subjected to amino acid analysis. Reduce to arene.

[0005] Next, the nitroarene is added to the reduction column 18.
Shortly before the elution, the flow is switched to the flow path 2 and only the amino arene is introduced into the second column 20 for separation. Further, the amount of fluorescence from the liquid to be measured is measured by the fluorescence photometer (FP) 22 by switching to the channel 3. In addition, an apparatus as shown in FIG. 2 was sometimes used to analyze dinitroarene (see Japanese Patent Application Laid-Open No. 7-253420).

[0006] In the figure, this apparatus comprises an eluent storage tank 1.
From 0, the liquid sending pump 12 sends the eluent. A liquid to be measured containing dinitroarene is injected into the eluent from the injector 14 and reduced to diaminoarene by a catalytic reduction column 18 filled with Zn, Cd, or the like. Further, the diaminoarene is separated by the separation column 20. The eluate from the separation column 20 is mixed with the luminescent reagent in the luminescent reagent storage tank 26 sent out by the solution sending pump 24, and the amount of chemiluminescence from the luminescent reagent mixture is measured by the chemiluminescent detector 28.

In recent years, there has been a demand for simultaneous analysis of many components for more reliable analysis. In the measuring apparatus shown in FIGS. 1 and 2, only nitropyrene or only dinitropyrene is used. , But simultaneous analysis of many components was very difficult. Therefore, in order to easily perform simultaneous analysis of many components,
In some cases, a device as shown in FIG. 3 was used (issued on January 10, 1997, subsidized by the Ministry of Education, Science and Technology,
Public Symposium, Behavior and Toxicity of Unregulated Air Pollutants-Carcinogen-Related Substances-Performance Abstracts, Determination of Nitropolycyclic Aromatic Hydrocarbons, Kanazawa Univ., Yakuhin, Kazuichi Hayakawa).

In this figure, in this apparatus, a liquid sending pump 12a sends an eluent from an eluent storage tank 10a. A liquid to be measured in which nitroarene has been reduced to aminoarene in advance is injected from the injector 14 into the eluate, and the eluate is introduced into the separation column 20a via the flow path switching valve 30 to separate the aminoarene. The eluate from the separation column 20a is mixed with the luminescent reagent in the luminescent reagent storage tank 26 sent out by the solution sending pump 24, and the chemiluminescence detector 28 measures the amount of chemiluminescence from the luminescent reagent mixture.

In this apparatus, the flow switching valve 30 is switched to introduce the eluent in the eluent storage tank 10b sent out by the liquid sending pump 12b into the separation column 20b to separate polycyclic aromatic hydrocarbons. Fluorescence (FP) photometer 2
2, the amount of fluorescence from the liquid to be measured is measured. This enables simultaneous analysis of nitroarenes and polycyclic aromatic hydrocarbons.

[0010]

However, even in the apparatus as shown in FIG. 3, there has been a demand for further simplification of operations such as pretreatment. In other words, although it is excellent in that it allows simultaneous analysis of nitroarenes and polycyclic aromatic hydrocarbons, it is necessary for the operator to reduce nitroarenes by batch method and convert them to aminoarenes as pretreatment. There is, it is troublesome and time consuming.
Also, with such pretreatment, aminoarenes are very oxidizable and chemically unstable,
High sensitivity analysis became very difficult, and the point that reproducibility and accuracy fell was also considered as a problem.

Further, even in the apparatus as shown in FIG. 3, further improvement of the separating ability has been desired. In other words, the appropriate technology when dinitropyrene and the like are further included in the target component has not yet been established, and the removal of contaminants by pretreatment is insufficient, or other purposes such as dinitropyrene due to some cause. In some cases, interference peaks overlap components, and there has been a strong demand for the development of a technique that can perform simultaneous analysis of more components with high sensitivity.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a measuring method and a measuring apparatus capable of easily and highly sensitively analyzing more trace components simultaneously. Is to do.

[0013]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies and as a result, introduced a liquid to be measured into a pretreatment column to remove impurities eluting earlier than the target component. After that, the components developed in the pretreatment column are simultaneously eluted by the backflush method, and the liquid to be measured obtained by the backflush method is subjected to a chemical treatment so that the target component elutes at the elution position of the contaminant. After that, by introducing into a separation column, simultaneous analysis of more components such as nitroarenes, dinitroarenes, and polycyclic aromatic hydrocarbons, which was extremely difficult in the past, can be performed easily and with high sensitivity. They have found that they can do this and have completed the present invention.

That is, the method for simultaneous measurement of multiple components according to the present invention is characterized by comprising an online pretreatment step, a chemical treatment step, a separation step, and a target component detection step. Here, the on-line pretreatment step is to introduce a liquid to be measured containing one or more target components into a pretreatment column to remove impurities eluting earlier than the target components, and then use a backflush method. Each component developed in the pretreatment column is eluted simultaneously. Further, the chemical treatment step comprises:
The liquid to be measured obtained by the backflush method is introduced into a chemical treatment column, and a chemical treatment is performed so that the target component elutes at the elution position of the contaminant.

In the separation step, the target liquid obtained in the chemical treatment step is introduced into a separation column to separate a target component.
The target component detection step detects the target component separated in the separation step. In order to achieve the above object, a multi-component simultaneous measurement device according to the present invention is characterized by comprising an online pre-processing unit, a chemical processing unit, a separation unit, and a target component detection unit.

Here, the on-line pretreatment means introduces a liquid to be measured containing one or more target components into a pretreatment column, removes contaminant components eluting earlier than the target components, and then backflushes them. The components developed in the pretreatment column are eluted at the same time.

Further, the chemical treatment means introduces the liquid to be measured obtained by the backflush method into a chemical treatment column and performs a chemical treatment so that the target component elutes at the elution position of the contaminant. The separation means introduces the liquid to be measured obtained by the chemical treatment means into a separation column to separate a target component. The target component detection unit detects the target component separated by the separation unit.

[0018]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a schematic configuration of a multi-component simultaneous measurement device according to an embodiment of the present invention.
Parts corresponding to those in FIGS. 1 to 3 are denoted by reference numeral 100, and description thereof is omitted. In the present embodiment, it is assumed that the liquid to be measured contains nitroarenes, dinitroarenes, polycyclic aromatic hydrocarbons, and the like, and trace components thereof are simultaneously analyzed. In the figure, the multi-component simultaneous measurement apparatus according to the present embodiment includes an online pre-processing unit, a foreign substance detection unit, a chemical processing unit, a separation unit,
Including target component detection means.

The above-mentioned on-line pre-processing means comprises water (pH
8.0, diethylamine (DEA)) and an eluent storage tank 110a storing an eluent A obtained by mixing 50/50 of methanol and an eluent storage tank 110b storing an eluent B composed of methanol. The eluents A and B are sequentially sent out by the pump 112 via the degasser 130, and the liquid to be measured containing nitroarene, dinitroarene, polycyclic aromatic hydrocarbon, and the like is injected into the eluent from the autosampler 114. I do.

The liquid to be measured is supplied to a switching valve 13.
NPpak-P (4.6) through points D and E of 2
mmi. d. × 10 mml) pretreatment column 13
4 and each component in the sample is converted into a pretreatment column 134.
It elutes in order from the one with the weaker affinity to the inner stationary phase.

The contaminant detecting means comprises an ultraviolet absorption photometer (UV) 136a and a fluorescence photometer (FP) 122a, and the ultraviolet absorption photometer (UV) 136a is a polycyclic aromatic eluted from the pretreatment column 134. The ultraviolet absorption of the hydrocarbon is measured, and the fluorometer (FP) 122a measures the amount of fluorescence.

Here, after removing contaminants eluting earlier than the target components, nitroarene and dinitroarene, the switching valve 132 is switched from the state shown by the dotted line to the state shown by the solid line (see FIG. 5). I'm backflushing. That is, the switching valve 1
The connection between ports D and E of 32 is disconnected and the connection between ports A and B is conducted. That is, the eluent A in the eluent storage tank 110a is caused to flow from the reverse direction through the pretreatment column 134 using the low-pressure gradient unit 138, which is a gradient elution unit, and the liquid sending pump 140, and the components developed in the column 134 are separated. After returning to one band, each component is eluted simultaneously.

The chemical treatment means comprises a reduction column 118 filled with a catalyst such as platinum, platinum / rhodium, palladium, and rhodium.
To convert the non-fluorescent nitro group into an amino group having strong fluorescence, thereby eluting the amino arene and diamino arene at the elution position of the polycyclic aromatic hydrocarbon as the contaminant. As a result, fluorescence is detected with high sensitivity.

The reduction column 118 is made of NPpak-
R (4.6 mmid × 10 mm), and is maintained at 100 ° C. by a reaction oven 144 which is a constant temperature means. Further, by switching the switching valve 142, it is possible to select whether to bring the reduction column 118 online or offline.

The separation means comprises a reverse-phase separation column 12.
0, and the measured liquid eluted from the reduction column 118 is passed through the switching valve 142 to the separation column 12.
Then, the composition of the eluent is sequentially changed by the low-pressure gradient unit 138, and components having different properties such as aminoarenes, diaminoarenes, and polycyclic aromatic hydrocarbons are simultaneously separated. The separation column 120 is
For example, NPpak (4.6) using a filler (ODS) in which an octadecyl group (C ₁₈ ) is chemically bonded to silica gel.
mmi. d. × 250 mml) and maintained at 40 ° C. by the column oven 146.

The target component detecting means comprises an ultraviolet absorption photometer (UV) 136b and a fluorescence photometer (FP) 122b, and the ultraviolet absorption photometer (UV) 136b is connected to the separation column 1
The ultraviolet absorption of the component eluted from 20 is measured, and the fluorometer (FP) 122b measures the amount of fluorescence from the eluted component.

The measurement results output from each of the ultraviolet absorption photometer (UV) 136 and the fluorescence photometer (FP) 122 are subjected to desired data processing by a computer 148 as a control means to obtain a chromatogram. ing. Also,
The waste liquid flowing out of the fluorescence photometer (FP) 122 is stored in a waste liquid tank 150.

The measuring device according to one embodiment of the present invention comprises:
It is configured as outlined above, and its operation will be described below with reference to FIG. First, while the reduction column 118 and the separation column 120 are conditioned, the liquid to be measured is injected from the autosampler 114 and introduced into the pretreatment column 134.

Here, the weakly retained components are eluted from the pretreatment column 134 (step 100), and this is eluted with an ultraviolet absorption spectrophotometer (UV) 136a and a fluorescence photometer (FP) 122a.
(Step 102). Then, among the weakly retained components and the polycyclic aromatic hydrocarbons, components having a low molecular weight elute, and among the strongly retained nitroarenes, dinitroarenes and polycyclic aromatic hydrocarbons,
When it is confirmed that a component having a high molecular weight is retained in the pretreatment column 134, the switching valve 132 is switched to perform backflushing (step 104).

That is, the eluent A
Is flowed from the opposite direction to the pretreatment column 134, and after each developed component returns to one band, that is, each component is simultaneously eluted. The liquid to be measured back-flushed in the pretreatment column 134 is introduced into the reduction column 118. Thereafter, the gradient elution of the eluents A and B is started by the low pressure gradient unit 138 and the pump 140.

As described above, in this embodiment, each component such as nitropyrene, dinitropyrene and polycyclic aromatic hydrocarbon is simultaneously eluted from the pretreatment column by backflushing.

The reduction column 118 reduces the nitro groups of nitroarenes, dinitroarenes and other nitro compounds in the test solution using the eluent A while maintaining the temperature at 100 ° C., as shown in FIG. Into an amino group (step 106). Here, in the present embodiment,
For such reduction, a methanol-based eluent A is used. Further, since the reduction column 118 filled with a catalyst such as platinum or platinum / rhodium is used, its deterioration can be prevented and the service life can be extended.

The separation column 120 gradient-elutes an eluent obtained by mixing methanol and a basic (diethylamine) solvent to form an aminoarene,
Components having different properties such as diaminoarenes and polycyclic aromatic hydrocarbons are simultaneously separated (step 108).

The eluted components are detected by the detection means at the subsequent stage (step 100), and quantification and qualification are performed by a computer. For example, in a reverse-phase separation column 120,
Since aminoarenes elute earlier than polycyclic aromatic hydrocarbons and diaminoarenes elute earlier than aminoarenes, the number of substituents must be estimated by comparing the elution position of the actual sample with the elution position of the standard sample. Can be.

That is, when the liquid to be measured contains a compound having a nitro group such as nitroarene or dinitroarene, the nitro group having no fluorescence is reduced in the reduction column 118 and converted into an amino group having strong fluorescence. Therefore, switching of the switching valve 142 causes the reduction column 1
Compare the chromatogram obtained by putting 18 offline and the chromatogram obtained by putting online, and if the peak of the component for which fluorescence was detected disappears, it is nitroarene, etc. Can be confirmed.

In addition, information for determining whether or not a nitro group is reduced to an amino group can be easily obtained only by switching the switching valve 142 so as to determine whether or not the substance is a nitroarene-related substance. Unknown nitroarenes (all nitro compounds) can be easily found. As described above, in the present embodiment, the backflush method is employed in the online preprocessing.

That is, in order to analyze nitroallene and the like, if each component was introduced into the reduction column in a state of being developed in the pretreatment column without backflushing,
Nitroallene near the column outlet elutes faster than contaminants that are slower than nitroallene on the separation column, but is selectively detected.However, dinitroallene near the column inlet separates faster even after reduction. In some cases, it may not be possible to overtake contaminant components, and the peak of dinitroarene may overlap with the interference peak of contaminant components separated earlier, making it difficult to selectively measure more components including dinitroarene. there were.

Therefore, in this embodiment, after the contaminant components are removed by the pretreatment column, each component developed in the column is back-flushed and returned to one band, that is, each component is simultaneously subjected to the pretreatment. By eluting from the column, more target components such as nitroarenes and dinitroarenes can be more clearly separated.

In this embodiment, a sample is injected by the liquid sending pump 112 or the like, and the sample is injected into the pretreatment column 1.
34 to elute. Further, after the backflush, for example, the target component passes through the switching valve 142 or the like, and the reduction column 144 or the separation column 146 or the like.
After that, cleaning and conditioning of the pretreatment column 134 and the like are performed. In addition, the liquid sending pump 1
Backflush of the pretreatment column 134 and subsequent gradient elution are performed by 40 or the like.

As described above, in the present embodiment, the two liquid feed pumps 11 each having the role described above are used.
By providing 2,140 etc., it is possible to wash and condition the pretreatment column 134 etc. during gradient elution, and to greatly shorten the analysis time as compared with those without such contrivance. be able to.

In this embodiment, a reduction column packed with a catalyst such as platinum, platinum / rhodium, palladium and rhodium is used for reduction. That is, a contact type column such as zinc or cadmium was sometimes used as the reduction column. However, when such a contact type reduction column is used, metals such as zinc and cadmium are dissolved in the solution at the same time as the reduction, thereby deteriorating the reduction column. This results in poor reproducibility. In addition, the influence on the detection method and the effect on the environment due to heavy metal contamination in the waste liquid are also conceivable.

Further, in such a contact type reduction column, when a chemiluminescence detection method is used for detection and acetonitrile is used as an eluent, no reducing ability is exhibited. When methanol is used, it has a reducing ability, but the chemiluminescence detection method raises the background and the sensitivity is insufficient. Therefore, as a result of studying various types of reduction columns, the present inventors have confirmed that it is optimal to use a reduction column using a catalyst such as platinum, platinum / rhodium, palladium, and rhodium. .

In this embodiment, an alkaline eluent is used for reduction and separation. That is, in the conventional separation method, an eluent having a low pH was sometimes used. However, when such an eluent having a low pH is used, when dealing with a larger amount of trace components as in the present embodiment, the peak of diaminopyrene may be tailed in the reduction column and the separation column. Was. Therefore, the present inventors examined the pH of the eluent, and as a result, when performing simultaneous analysis of more components such as nitropyrene and dinitropyrene as in the present embodiment, an alkaline eluent is most suitable. Confirmed that there is.

As a result, the fluorescence intensity of diaminoarene and aminoarene is increased, and tailing of diaminopyrene on the reduction column and the separation column is prevented, and the peak shape can be improved to a sharper one. Such selective measurement of each component can be performed with higher sensitivity.

Further, in the present embodiment, the eluent A
To adjust the pH of the solution to alkaline, instead of using an alkali such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), an amine p such as diethylamine (DEA).
The addition of the H adjuster can extend the life of the column when an alkaline eluent is used.

As described above, according to the measuring apparatus of the present embodiment, by switching the switching valves 132 and 142 using the column switching method, the nitroarene,
Simultaneous analysis of more minor components, such as dinitroarenes and polycyclic aromatic hydrocarbons, can be detected easily and with high sensitivity. The reason why the above-described analysis method is used in the present embodiment is as follows.

That is, in order to simultaneously analyze nitroallene and polycyclic aromatic hydrocarbons, a chemiluminescence detection method was often used as shown in FIG. However, if such a chemiluminescence detection method is used, it is very difficult to use a suitable catalytic reduction column in the present embodiment. In addition, since it is very difficult to use the gradient elution method and measurement with a solvent having a constant composition is mainly performed, when performing simultaneous separation of more components having different properties as in the present embodiment, Did not lead to adoption. In addition, the composition was easily affected by the composition of the eluent and the dissolved oxygen in the eluent, and satisfactory reproducibility could not be obtained. Further, it is necessary to mix a reaction reagent in order to increase the amount of chemiluminescence, which is troublesome. further,
In the measurement of exhaust gas, a batch-type pretreatment was required, which was troublesome.

Therefore, as a result of studying various analytical methods by the present inventors, it was found that simultaneous analysis of more components such as nitroarenes, dinitroarenes and polycyclic aromatic hydrocarbons was performed easily and with high sensitivity. Has confirmed that the measurement method according to the present embodiment is optimal.

[0049]Reduction performance of reduction column  Next, in order to verify the reducing ability of the reducing column 118,
Using the measuring device according to the present embodiment,
An actual sample from which dust obtained from exhaust gas was extracted,
After Soxhlet extraction using chloromethane, dimethyl
Measured including those dissolved in formamide (DMF)
The constant solution was measured under the following measurement conditions.

[0050]Measurement condition  Column: Pretreatment column (4.6 mmid × 10 mml), reduction column (4.6 mmid × 10 mml), separation column ODS (4.6 mmid × 250 mml) Eluent A: water (pH 8. 0, (diethylamine) DEA) / methanol (50/50) Eluent B: Methanol gradient elution: time min A% B% 0 100 0 5.0 100 100 0 40.0 0 100 50.0 0 100 50. 1 1000 l cycle 60.0 min Flow rate: 1.0 ml / min Column temperature: Pretreatment column, separation column 40 ° C, reduction column 100 ° C Sample injection amount: 10 μl Ultraviolet absorption detection wavelength: 254 nm Fluorescence detection wavelength: time (min) ) Ex (nm) Em (nm) Gain 0 min ~ 375 460 x 100 20 min ~ 365 436 x 10 0

As is apparent from FIG. 8, when the reduction column 118 shown in FIG. I is turned on-line, a peak corresponding to nitropyrene (NP) can be detected, while the off-line shown in FIG. In such a case, such a peak could not be detected. Thus, reduction of nitropyrene (NP) to aminopyrene (AP) by the reduction column 118 could be confirmed.

Next, for the purpose of verifying the timing of backflush of the pretreatment column 134, 17 polycyclic aromatic hydrocarbon (PAH) standard samples, 1: naphthalene (Na)
pthalene), 2: Acenaphthylene,
3: Acenaphthene, 4: Fluorene, 5: Phenanthrene,
6: Anthracene, 7: Fluoranthene, 8: Pyrene, 9: Benz
[a] Anthracene (Benzo [a] Anthracene), 10: Chrysene, 11: Benz [e] pyrene (Benzo [e])
pyrene), 12: Benzo [b] fluoranthene (Benzo [b]
fluoranthene), 13: Benz [k] fluoranthene (Be
nzo [k] fluoranthene), 14: Benz [a] pyrene (Benz)
o [a] pyrene), 15: dibenzo [a, h] anthracene, 16: benzo [g, h,
l] perylene (Benzo [g, h, l] perylene), 17: Indeno [1,2,3-c, d] pyrene (Indeno [1,2,3-c, d] pyr
ene) was measured.

The measurement conditions were the same as described above, and a polycyclic aromatic hydrocarbon having a short retention time eluted from the pretreatment column 134 was detected by an ultraviolet absorption spectrophotometer (UV) 136a to obtain a chromatogram.

FIG. 9 (a) shows the obtained chromatogram. The backflushing timing of the pretreatment column 134 is determined based on these elution positions. Switching of the switching valve 132 was performed at the elution position A. In this case, of the 17 component polycyclic aromatic hydrocarbon standard samples, 2
Ingredients: 1: Naphthalene, 2: Acenaphthylene, UV absorption spectrophotometer 136a
(UV) or with a fluorescence photometer (FP) 122a.

Next, after the pretreatment column 134 is back-flushed, the reduction column 118 and the separation column 120 are flushed.
The liquid to be measured eluted from the sample is passed through an ultraviolet absorption photometer (UV) 13
6b. As a result, as is clear from FIG. 3B, the remaining 15 components of polycyclic aromatic hydrocarbon (PAH)
The standard sample was clearly separated, indicating that extremely sensitive detection was possible.

Next, nitropyrene (NP) and 1,3
The liquid to be measured including-, 1-6,1-8 dinitropyrene (DNP) standard sample was measured. The measurement conditions were the same as above.
As a result, as shown in FIG. 9C, 1,6-, 1-8,1-3 dinitropyrene (DNP) and nitropyrene (NP) were detected with extremely high sensitivity.

Next, the liquid to be measured including the actual sample was measured. The measurement conditions were the same as above. As a result, as is clear from FIG. 10 (a), nitropyrene (N
P), dinitropyrene (DNP) and polycyclic aromatic hydrocarbons were detected with extremely high sensitivity.

Further, as a result of measurement of another actual sample, as is apparent from FIG. 3B, the vicinity of the peak of dinitropyrene B and 1,3-, 1-6,1 shown in FIG. Several peaks not corresponding to -8-dinitropyrene and nitropyrene standard samples were detected. These peaks are considered to be unknown nitroarenes from the elution position. Therefore, it is shown that the use of the measuring device according to the present embodiment has made it possible to discover unknown nitroarenes (all nitro compounds). In addition, the use of a mass spectrometer (MS) allows the identification of such unknown nitro compounds.

[0059]Nitropyrene linearity  FIG. 11 shows the nitropy obtained by the measuring device according to the present embodiment.
The Len calibration curve is shown. As is clear from the figure, the calibration curve
Sufficient linearity was obtained in a wide range of 1000 pg or less.
Is shown. In addition, as the measuring device of the present invention,
The present invention is not limited to the above-described embodiment, but may
Various modifications are possible.

For example, as shown in FIG. 12, the pretreatment column 234 is
6 may be provided. 4 are added to the portions corresponding to those in FIG. As a result,
Since the temperature of the pretreatment column 234 can be maintained by the column oven 246, the online pretreatment can be performed more favorably.

As shown in FIG. 13, the separation column 352 for more clearly separating the polycyclic aromatic hydrocarbons separated in the pretreatment column 334 is replaced with a pretreatment column 334.
Along with the separation column 320, it may be provided in a column oven 346. As a result, the polycyclic aromatic hydrocarbon can be more clearly separated, and the measurement can be performed with higher sensitivity.

In the above embodiment, the switching valves 132, 142, 232, 242, 332,
Although the example in which the switching of the switching valve 342 is performed manually has been described, as shown in FIG.
May be performed.

For example, when a polycyclic aromatic hydrocarbon eluted earlier than the target component such as nitroarene or dinitroarene is monitored in real time by a computer 348 or the like, and a contaminant component eluted earlier than the target component is detected, By automatically switching the switching valve 332 and automatically performing the backflush, the measurement becomes easier. In addition, by automatically switching the switching valve 342 and automatically setting the reduction column 344 on-line or off-line, such an operation is compared with that performed manually. It can also be facilitated.

In each of the above embodiments, an example was described in which an ultraviolet absorptiometer was used as a detecting means in order to perform various nitroarene analyses. However, the present invention is not limited to this, and a wider target of analysis may be considered. Then, other detection means, for example, a visible absorption spectrophotometer, or a multi-wavelength detector (multi-channel detector) may be appropriately provided. Furthermore, in each of the above embodiments, an example was described in which one kind of eluent was used to flow to the liquid sending pump 112 and the like. However, the present invention is not limited to this. In this case, separate components may be used.

[0065]

As described above, according to the method for simultaneous measurement of multiple components according to the present invention, the liquid to be measured is introduced into the pretreatment column to remove impurities eluting earlier than the target component. The components developed in the pretreatment column are simultaneously eluted by the flash method, and the measured liquid obtained by the backflush method is introduced into the chemical treatment column so that the target component elutes at the elution position of the contaminant. After the chemical treatment, it was introduced into the separation column, so that simultaneous analysis of more trace components such as nitroarenes, dinitroarenes and polycyclic aromatic hydrocarbons, which had been extremely difficult in the past, was easily and easily performed. Can be done to sensitivity. Further, according to the multi-component simultaneous measurement device according to the present invention, after introducing the liquid to be measured into the pre-treatment column to remove contaminant components eluting earlier than the target component, the back-flushing method allows the pre-treatment column to enter the pre-treatment column. An on-line pretreatment means for simultaneously eluting each developed component, and the liquid to be measured obtained by the backflush method is introduced into a chemical treatment column, and a chemical treatment is performed so that a target component is eluted at an elution position of a contaminant. Since it is provided with a chemical treatment means and a separation means for introducing a liquid to be measured obtained by the chemical treatment means into a separation column to separate a target component, nitroarenes, dinitroarenes, and other varieties which have been extremely difficult in the past. Simultaneous analysis of more trace components such as cyclic aromatic hydrocarbons can be performed easily and with high sensitivity.

[Brief description of the drawings]

FIG.

FIG.

FIG. 3 is an explanatory diagram of a schematic configuration of a conventional measuring device.

FIG. 4 is an explanatory diagram of a schematic configuration of a multi-component simultaneous measurement device according to an embodiment of the present invention.

5 is an explanatory diagram of a column switching method of the device shown in FIG.

FIG. 6 is a flowchart showing an operation procedure of the apparatus shown in FIG.

FIG. 7 is an explanatory diagram of an operation of a catalytic reduction column used in the apparatus shown in FIG.

FIG.

FIG.

10 is a chromatogram showing the results of actual measurement of nitroarenes, dinitroarenes, polycyclic aromatic hydrocarbons, and the like using the apparatus shown in FIG.

FIG. 11 is an example of a nitropyrene calibration curve obtained by the apparatus shown in FIG.

FIG.

FIG. 13 is a modification of the apparatus shown in FIG.

[Explanation of symbols]

122, 222, 322 Fluorometer (target component detecting means, impurity detecting means) 132, 142, 232, 242, 332, 342 Switching valve 134, 234, 334 Separation column 136, 236, 336 UV absorption photometer ( 138, 238, 338 Low pressure gradient unit (gradient elution unit) 144, 244, 344 Catalytic reduction column (chemical treatment column) 146, 246, 346 Separation column 148, 248, 348 Computer (control means)

Claims (2)

[Claims] 1. A method capable of simultaneously analyzing multiple components using liquid chromatography, comprising introducing a liquid to be measured containing one or more target components into a pretreatment column, An on-line pretreatment step of simultaneously eluting each component developed in the pretreatment column by the backflush method after removing the eluting contaminants early, and introducing the liquid to be measured obtained by the backflush method to the chemical treatment column A chemical treatment step of performing a chemical treatment so that the target component elutes at the elution position of the contaminant; and a separation step of introducing the liquid to be measured obtained in the chemical treatment step into a separation column to separate the target component. And a target component detection step of detecting the target component separated in the separation step. 2. An apparatus capable of simultaneous analysis of multiple components using a liquid chromatograph, wherein a liquid to be measured containing one or more target components is introduced into a pretreatment column, so that the target components can be analyzed faster than the target components. After removing contaminants to be eluted, on-line pretreatment means for simultaneously eluting each component developed in the pretreatment column by the backflush method, and introducing the liquid to be measured obtained by the backflush method into the chemical treatment column. A chemical treatment means for performing a chemical treatment so that the target component elutes at the elution position of the contaminant; and a separation means for introducing the liquid to be measured obtained by the chemical treatment means into a separation column to separate the target component. And a target component detecting means for detecting a target component separated by the separating means.