JPH01214754A - Composition-ratio determining apparatus - Google Patents

Abstract

PURPOSE:To make it possible to compute the contents of individual compounds accurately, when the composite peaks of a plurality of overlapped compounds are analyzed, by solving specified simultaneous equations using the output of GC/MS (gaschromatograph/mass spectrometer) for a plurality of fragments whose sensitivities are known beforehand and using sensitivities. CONSTITUTION:The peak waveforms of compounds A and B are overlapped. A standard sample incorporates one kind of the compounds A and B. The concentration of the standard sample is known. The standard sample is analyzed with a GC/MS 1 beforehand. The ion chromatogram of fragment ions (mass numbers m1 and m2) characterizing each compound is measured. The obtained ion chromatogram is processed in an operating part 2. Each peak area is computed. The sensitivities of the compounds A and B for 1mug are obtained and stored in a memory part 5. For the composite peaks (A+B), the sensitivities of the compounds A and B, Pa1, Pa2, Pb1 and Pb2 which are stored in the memory part 5 are used. When the composite peaks (A+B) are measured, equations are used based on the sensitivities Pa1, Pa2, Pb1 and Pb2 of the outputs D1 and D2 of the GC/MS 1 at the mass numbers m1 and m2, and the contents of the compounds Ma and Mb are computed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composition ratio quantification device that measures the composition ratio of a sample containing a plurality of compounds using GC/MS (gas chromatograph/mass spectrometer). be.

(Prior Art) The composition ratio determination method using gas chromatography is a method for determining the composition ratio by utilizing the fact that the area of the peak in the chromatogram is proportional to the content of each compound. For example, in the modified percentage method, it is defined as . The correction coefficient here represents the ratio of the content of each compound to the peak area under a certain measurement condition, that is, the analytical sensitivity, and differs for each component compound. This method allows the composition ratio to be determined with relatively high accuracy, but in order to measure the peak area, it is necessary to completely separate the peak waveforms of various compounds in the chromatogram, so the separation column of the gas chromatograph is required. This has the disadvantage that the analysis time is long.

(Problems to be Solved by the Invention) In view of the above points, the present invention enables accurate determination of the content of individual compounds and compounds even if the peak waveforms of the chromatogram are not completely separated. Therefore, it is an object of the present invention to provide a composition ratio determination device that can determine composition ratios in a shorter time than conventional methods.

(Means for Solving the Problems) In the composition ratio determination device according to the present invention, specific fragment ions (quality m ml + m2 r...
), and when multiple compounds A and B with close peak waveforms are individually analyzed, the sensitivity (ion detection intensity) of the above specific fragment P a
+, P b+, P at, and P by in advance, and a set mass number ml of the mass spectrometer during sample analysis.
+ GC/MS output D r at rrl g,
Dt and the sensitivity of each fragment ion above Pa+, Pb
The content of each compound A, B at each time point m M
The content of each compound A, H in the sample can be determined by calculating the peak areas of the chromatograms formed by the contents M a and M b of each compound at multiple points in time, as well as calculating a and M b. It is equipped with an arithmetic unit that calculates .

(Effect) First, two types of compounds A and H whose peak waveforms are close to each other.
For each compound, select two types of fragment ions (such as OH and COOH) that characterize each compound.
Sensitivity (detection output) Pad of fragment ions contained in the unit concentration of each compound when each compound is analyzed individually.

Pa, and Pb, , Pb are measured and stored in advance.

In this case, two types of fragment ions (quality m number I'l
l 1 + mt ) need not be unique to one compound.

Next, in the actual analysis, that is, the analysis of the sample containing both compounds A and 13, the GC/MS outputs D I, D z and the sensitivities of each of the above fragment ions Pa+, Pb+ and Simultaneous equation from Pat, Pbt % formula % However, Pad: For example, when 1 μg of compound A is introduced into the chromatograph, the peak value of the single output due to the fragment ion m in A Pbn: 〃 Compound B ” ml 〃 p3
．． ;tt Compound A //m2 〃pb,:
"Compound B" mt "D,: Composite output at mass number m at one point while a mixed peak of both components A and B appears in actual sample measurement; Composite output Ma at mass number m, also: Above Content of compound A at the time of measurement Mb2 Content of compound B at the time of measurement is solved, content N of each compound at that time
Ma.

Find Mb.

If such processing is performed for multiple time points of one composite peak waveform and the peak areas of the two chromatogels formed by probing M a and M b obtained at each time point are calculated, each compound The content in the sample can be obtained.

(Example) Figure 1 shows an example of the device of the present invention.
The output of the SI is processed by a calculation unit 2 using a microcomputer and output to a printer 3 or CRT 4. Reference numeral 5 denotes a storage section in which calculation programs and the above-mentioned sensitivities are stored.

When measuring a sample with an unknown composition ratio using the above device, first, each compound A whose peak waveforms overlap each other,
A standard sample containing one type of H and whose concentration is known is analyzed in advance by GC/MSI, and fragment ions (mass numbers m, , m
Measure the ion chromatogram for 2). The ion cyromadogram thus obtained is processed by the calculation unit 2 to calculate the area of each peak.
The sensitivities Pa+, Pb+, Pat, and Pbt with respect to μg are determined and stored in the storage unit 5.

Next, a sample with an unknown composition ratio is analyzed. Figure 2 shows each compound A in the total ion chromatogram (TIG) output from the gas chromatograph.

This shows the peak waveforms of B, C, D, etc. For completely separated compounds C and D, the composition ratio in the sample can be easily calculated by finding the ratio of their peak areas. can do. Moreover, instead of this TIC, it is also possible to use an ion chromatogram of a fragment whose sensitivity has been determined in advance.

In the chromatogram shown in FIG. 2, the composition ratio of the individual compounds A and B cannot be calculated for the composite peak A+H in which the peaks of two types of compounds A and B overlap. Therefore, in that case, two types of fragments (m + ) have been measured in advance as described above.

m, ) sensitivity, that is, the sensitivity of each compound when each compound A and B is analyzed individually. GC/MS output Pa+, Pa2 and Pb+ with specific fragments (eg OH and CO0+1) contained in μg.

When measuring the composite peak A+H using Pb,
From the GC/MS output D + , D z at each mass number m , , m 2 and the above P al , P b + and Pat, P bt, the content of each compound at that point is determined as a solution to the above simultaneous equations. M a, M
Calculate b.

For one composite peak waveform, the above-mentioned measurements are performed at multiple time points, so M a obtained at each time point,
Plot Mb (it is not necessary to actually plot it, otherwise two chromatograms will be formed. Therefore, by calculating these peak areas, each compound A,
The content of H in the sample is obtained, and these are displayed on the printer 3 or CRT 4 together with the content of compounds C, D, etc.

In the above example, an example was shown in which two types of compounds overlapped as a composite peak, but it does not necessarily have to be two types, and for example, four types may be used as shown in FIG. 4. In that case, as shown in the figure, each compound A, B,
Four characteristic fragments m+ + for C and D
An ion chromatogram may be obtained for rrl t + rrl31 fY14. Also, these fragments do not necessarily have to be unique to each compound, even if each fragment is unique to all compounds A, B, C,
Even if it is common to D, the content of each compound M a , M b , M c ,
M d can be found.

Furthermore, as shown in Figure 5, if two of the three or more compounds A, B, and C that make up a composite peak are completely separated, the same It is also possible to use fragment mj.

(Effects of the Invention) According to the present invention, as described above, when analyzing a composite peak in which multiple compounds overlap, the GC/MS output and each sensitivity are calculated for multiple fragments whose sensitivities are known in advance. Since the content of each compound in the sample can be determined by solving the simultaneous equations used, the content of each compound can be determined without completely separating each peak waveform of the chromatogram using a gas chromatograph. can be determined accurately, and there is therefore no need to use a long separation column as in the conventional method, so there is an advantage that the composition ratio can be determined in a short measurement time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the device of the present invention, and FIG.
3 and 3 are explanatory diagrams of the same operation as above, FIG. 4 is an explanatory diagram of the operation of another embodiment, and FIG. 5 is an explanatory diagram of the operation of still another embodiment. Δ, B...Each compound in the sample

Claims (1)

[Claims] (1) GC/MS that analyzes compounds contained in a sample and outputs the ion chromatogram, and each unit concentration when multiple compounds A and B with overlapping peak waveforms are individually analyzed. The mass m_1, m contained in
Multiple fragment ion detection intensities of _2 Pa_1, P
A storage unit that stores a_2, Pb_1, and Pb_2 in advance, and a mass number m of each of the above fragment ions during sample analysis.
GC/MS output D_1, D_2 at _1, m_2 and each fragment ion detection intensity Pa_1, Pb_1,
From Pa_2 and Pb_2, the simultaneous equation Pa_1・Ma+
Calculate the solutions Ma and Mb of Pb_1・Mb=D_1 Pa_2・Ma+Pb_2・Mb=D_2, and calculate each solution M at multiple points in time.
A composition ratio quantification device comprising: a calculation section for calculating peak areas of chromatograms formed by a and Mb, respectively.