Lanthanide metal-1, 3-diketone complex detection method based on MALDI-TOF MS

Abstract

The invention discloses a method for detecting a lanthanide metal-1, 3-dione complex based on MALDI-TOF MS. The method comprises the following steps: preparing a detection sample of the lanthanide metal-1, 3-dione complex, then detecting by adopting a reflection mode, and detecting the lanthanide metal-1, 3-dione complex by adopting an MALDI-TOF MS under the conditions that the laser intensity is 45-55%, the voltage multiple is 13.9 * and the room temperature. After sample application, MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) is adopted for detection to obtain relative molecular mass and isotope distribution results. According to the method provided by the invention, the MALDI-TOF MS detection of the lanthanide metal-1, 3-dione complex can be realized, the molecular ion peak of the lanthanide metal-1, 3-dione complex molecule is obtained, the error of the detection result is less than 5ppm, and the detection requirement of high-resolution mass spectrum is met.

Description

Technical Field

[0001] This application relates to the field of lanthanide metal-1,3-dione complex detection technology, and in particular to a method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOFMS. Background Technology

[0002] Lanthanide-1,3-diketone complexes are organometallic complexes formed by the coordination chelation of lanthanide metal cations and deprotonated anions with 1,3-diketone groups. Current technologies require obtaining the relative molecular mass and high-resolution isotopic distribution of these compounds to accurately confirm their structure, determine their purity, and predict their properties.

[0003] Currently, mass spectrometry detection of lanthanide metal-1,3-diketone complexes involves separation and subsequent detection. Mass spectrometry detection of lanthanide metal cations is primarily performed using inductively coupled plasma mass spectrometry (ICP-MS), while anions with 1,3-diketone anions can be detected using negative-mode electrospray ionization (ESI-MS). Combining these two detection methods can provide effective evidence for the mass spectrometric identification of lanthanide metal-1,3-diketone complexes. However, relying solely on ESI-MS or ICP-MS is insufficient for the mass spectrometric identification of these substances.

[0004] However, the above detection methods are time-consuming, involve complicated steps, require a large number of instruments, and cannot obtain accurate relative molecular mass and high-resolution isotope distribution results in a single detection.

[0005] The literature also reports on the DART-MS mass spectrometry detection method, which can be used for the mass spectrometry detection of lanthanide metal-1,3-dione complexes. However, due to instrument limitations, there are very few application examples, with only one paper supporting it.

[0006] Among various mass spectrometry detection methods, matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS) is widely used for the mass spectrometric analysis of macromolecules such as polysaccharides, proteins, and polymers due to its high resolution and high sensitivity. However, this detection method has not been found to be used for the detection of lanthanide metal-1,3-diketone complexes.

[0007] However, MALDI-TOF MS has not been used to detect lanthanide metal-1,3-dione complexes.

[0008] The information disclosed in the background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] This application addresses the aforementioned technical problems by providing a method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS. This method utilizes MALDI-TOF MS to achieve high-resolution mass spectrometry detection of lanthanide metal-1,3-dione complexes, providing a simpler, more effective, and cost-efficient means for the mass spectrometry analysis and detection of lanthanide metal-1,3-dione complexes. This application provides a method for the detection of lanthanide metal-1,3-dione complexes based on MALDI-TOF MS, including the following steps: After preparing the lanthanide metal-1,3-dione complex for detection, the relative molecular mass and isotope distribution were obtained by reflection mode detection at a laser intensity of 45-55%, a voltage multiplier of 13.9×, and room temperature.

[0010] Preferably, the preparation of the test sample includes the following steps: Dissolving lanthanide metal-1,3-dione complexes yields lanthanide metal-1,3-dione complex solutions; The test sample was obtained by mixing the lanthanide metal-1,3-dione complex solution with the DHB matrix solution. The concentration of the lanthanide-1,3-dione complex solution in the sample was 1 mg / mL.

[0011] Preferably, the preparation of the DHB matrix solution includes the following steps: DHB was dissolved in TA30, and then 0.5 mM sodium chloride solution and 0.5 mM potassium chloride solution were added to prepare a DHB matrix solution with a concentration of 20 mg / mL.

[0012] Preferably, TA30 is prepared by mixing acetonitrile with ultrapure water containing 0.1% trifluoroacetic acid at a volume ratio of 30:70.

[0013] Preferably, the lanthanide metal-1,3-dione complex is tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium or tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV).

[0014] Preferably, the solvent in the lanthanide-1,3-dione complex solution is chloroform.

[0015] Preferably, the lanthanide metal-1,3-dione complex solution and the DHB matrix solution are mixed at a volume ratio of 1:1.

[0016] Preferably, the [M+K] of the obtained lanthanide metal-1,3-dione complex + The error between the mass spectrometry results and the theoretical values ​​is less than 5 ppm.

[0017] Preferably, the lanthanide metal-1,3-dione complex is tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV) or tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium. The beneficial effects that this application can produce include: 1) The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS provided in this application utilizes MALDI-TOF MS for high-resolution mass spectrometry detection of lanthanide metal-1,3-dione complexes. It can obtain high-resolution mass spectrometry detection results of lanthanide metal-1,3-dione complexes in one step, and obtain accurate relative molecular mass and high-resolution isotope distribution results. The results obtained meet the requirements of high-resolution mass spectrometry.

[0018] 2) The MALDI-TOF MS-based detection method for lanthanide metal-1,3-dione complexes provided in this application utilizes MALDI-TOF MS instruments, which are more widely distributed and easier to maintain than DART MS instruments, making the detection method simple, rapid, and inexpensive. The method provided in this application can detect lanthanide metal-1,3-dione complexes using MALDI-TOF MS, obtaining the molecular ion peak of the lanthanide metal-1,3-dione complex molecule. The detection result error is less than 5 ppm, which meets the detection requirements of high-resolution mass spectrometry. This provides a simple, effective, and low-cost detection method for high-resolution mass spectrometry detection of lanthanide metal-1,3-dione complexes. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained from the provided drawings without creative effort. Figure 1 The prediction results of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium by Agilent data analysis software in Example 1 provided in this application.

[0020] Figure 2 The results of MALDI-TOF MS detection of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium in Example 1 provided in this application; Figure 3 The prediction results of tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV) by Agilent data analysis software in Example 2 provided in this application.

[0021] Figure 4The results of MALDI-TOF MS detection of cerium tetrakis(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)(IV) in Example 2 provided in this application; Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but this does not limit the present invention in any way. Any modifications or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0023] Unless otherwise specified, all materials and instruments used in the following embodiments were obtained through commercial channels; and all detection methods used are existing methods unless otherwise specified. Example

[0024] 1. Detection instruments and reagents: Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS, New UltrafleXtreme, Bruker Daltonics Inc.) was used. The tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium, sodium chloride, potassium chloride, trifluoroacetic acid, and acetonitrile were all purchased from Beijing Bailingwei Technology Co., Ltd.

[0025] The DHB matrix used was purchased from Beijing Bruker Company. The matrix solution preparation method was based on Bruker Company's recommended method, as follows: Preparation of 2,5-dihydroxybenzoic acid (DHB) solution: DHB was dissolved in TA30 (acetonitrile and ultrapure water containing 0.1% trifluoroacetic acid at a volume ratio of 30:70). After adding 0.5 mM sodium chloride solution and 0.5 mM potassium chloride solution, a DHB matrix solution with a concentration of 20 mg / mL was prepared. Tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium was dissolved in chloroform to obtain a solution of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium.

[0026] 2. Mass spectrometry conditions: The spotting conditions were as follows: 5 µL of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium solution was mixed with 5 µL of DHB matrix solution, and 1 µL was taken to obtain the test sample. The concentration of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium in the test sample was 1 mg / mL.

[0027] The mass spectrometry results of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium were obtained by detection in reflectance mode, with laser intensity of 45-55%, voltage multiplication factor of 13.9×, and room temperature conditions. (See figure below.) Figure 2 As shown.

[0028] 3. Results Analysis: Figure 1 To input the molecular formula C of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium into Agilent's data analysis software... 33 H 57 After O6Yb, set the parameters as shown in the figure: Charge: +1; Ion type: (M+K) + ; Spectral parameters: constant FWEM: 0.05; table parameters: m / z to 4 decimal places; abundance to 2 decimal places; display set to Gaussian plot; then select the [M+K] of tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) ytterbium obtained from adduct ion prediction. + The high-resolution mass spectrometry results show a distinct characteristic isotopic distribution. Because ytterbium has a broad isotopic distribution, among which... 174 Yb is the most abundant isotope, which can serve as a marker when assigning mass differences. Furthermore, the highly characteristic isotopic distribution fingerprint of ytterbium makes it easily identifiable from mass spectra.

[0029] Figure 2 The results of MALDI-TOF MS detection of ytterbium tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid) show a clear presence of [M+Na]. + and [M+K] + The high-resolution mass spectrometry signal was obtained, and its isotopic distribution is consistent with the theoretical results. Specifically, m / z 726.3488 represents [M+Na]. + The isotopic signal peak with a relative intensity of 100% in the high-resolution mass spectrometry results, at m / z 762.3175, is [M+K]. + The high-resolution mass spectrometry results show isotopic signal peaks with a relative intensity of 100%, and simultaneously, [M+K] + The mass spectrometry signal intensity is higher than that of [M+Na]. + The mass spectrum signal intensity can therefore be used to measure [M+K]. + In the high-resolution mass spectrometry results, m / z 762.3175 and Figure 1 Compare with m / z 762.3179.

[0030] The calculated and measured [M+K] + The error between the high-resolution mass spectrometry results and the theoretical value was 0.5 ppm, which is significantly less than 5 ppm. Example

[0031] The difference from Example 1 is that the sample tested was cerium tetrakis(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)(IV). The test results are as follows. Figure 4 As shown, the prediction results from Agilent's data analysis software for this sample are as follows: Figure 3 As shown.

[0032] Depend on Figures 3-4 The comparison shows that, using the method provided in this application, the measured [M+K] + The error between the high-resolution mass spectrometry results and the theoretical value was 2.5 ppm; Based on the above analysis, it can be seen that the mass spectrometry data of tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV) obtained by MALDI-TOF MS meet the requirements of high-resolution mass spectrometry detection. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS, characterized in that, Includes the following steps: After preparing the lanthanide metal-1,3-dione complex for detection, the relative molecular mass and isotope distribution were obtained by reflection mode detection at a laser intensity of 45-55%, a voltage multiplier of 13.9×, and room temperature.

2. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 1, characterized in that, The preparation of test samples includes the following steps: Dissolving lanthanide metal-1,3-dione complexes yields lanthanide metal-1,3-dione complex solutions; The test sample was obtained by mixing the lanthanide metal-1,3-dione complex solution with the DHB matrix solution. The concentration of the lanthanide-1,3-dione complex solution in the sample was 1 mg / mL.

3. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 2, characterized in that, The preparation of DHB matrix solution includes the following steps: DHB was dissolved in TA30, and then 0.5 mM sodium chloride solution and 0.5 mM potassium chloride solution were added to prepare a DHB matrix solution with a concentration of 20 mg / mL.

4. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 3, characterized in that, TA30 is prepared by mixing acetonitrile with ultrapure water containing 0.1% trifluoroacetic acid at a volume ratio of 30:

70.

5. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 1, characterized in that, Lanthanide metal-1,3-diketone complexes are tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium or tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV).

6. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 2, characterized in that, The solvent in the solution of lanthanide metal-1,3-dione complexes is chloroform.

7. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 2, characterized in that, The lanthanide metal-1,3-dione complex solution and the DHB matrix solution were mixed at a volume ratio of 1:

1.

8. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 2, characterized in that, The obtained lanthanide metal-1,3-dione complexes [M+K] + The error between the mass spectrometry results and the theoretical values ​​is less than 5 ppm.

9. The method for detecting lanthanide metal-1,3-dione complexes based on MALDI-TOF MS according to claim 1, characterized in that, Lanthanide metal-1,3-dione complexes are tetra(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)cerium(IV) or tris(2,2,6,6-tetramethyl-3,5-heptadecanoic acid)ytterbium.

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