A method and application of coupling organic matter molecular chemical structure with intelligent grid

Abstract

The present invention belongs to the technical field of organic matter molecular analysis and discloses a method and application of coupling the chemical structure of organic matter molecules to an intelligent grid. Based on Fourier transform ion cyclotron resonance mass spectrometry (FT-ICRMS) data, the present invention identifies molecular formulas through the CAS website, and divides the identified organic matter molecular formulas and organic matter with the same number of double bonds into the same group of organic matter. Using methylene, imino, hydrogen-phosphorus bonds, oxygen, and sulfur as units of difference, different molecular formulas in the same group of organic matter are used as points, and the units of difference are used as lines. Different points are connected by lines to obtain an organic matter molecular connection grid; the properties of organic matter molecules are analyzed based on the units of difference between organic matter molecular formulas, and the migration and transformation mechanism of organic matter molecules in lakes is analyzed in combination with the characteristics of organic matter molecules, microbial metabolism, and environmental impact.

Description

Technical Field

[0001] The present invention relates to the technical field of organic matter molecule analysis, and in particular to a method and application of coupling the chemical structure of organic matter molecules to an intelligent grid. Background Art

[0002] Current methods for analyzing organic matter molecules rely on Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to determine the elemental composition and number of double bonds, thereby defining and analyzing the molecular species. A common method for analyzing FT-ICR MS data is to create a scatter plot using the H / C and O / C ratios in the data as the horizontal and vertical axes, with colors representing the FT-ICR MS peak intensity of the different organic matter molecules. Organic matter molecules are classified according to saturated components (H / C > 1), unsaturated components (H / C ≤ 1), high-oxygen components (O / C > 1), and low-oxygen components (O / C ≤ 1). The paradigm diagram also provides a preliminary classification of organic matter, categorizing it into several common components: CHO, CHON, CHOS, CHONS, and CHOP. This preliminary classification of organic matter based on elemental identity is not conducive to analyzing its molecular properties. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and application of coupling the chemical structure of organic molecules to an intelligent grid to solve the problems existing in the prior art.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for coupling the chemical structure of organic molecules to an intelligent grid, comprising the following steps:

[0006] (1) Data screening

[0007] Classify the organic matter molecular formulas corresponding to the organic matter mass spectrum peaks identified in FT-ICR MS, and then screen the obtained organic matter molecular formulas;

[0008] (2) Molecular formula sorting

[0009] The screened organic matter molecular formulas were identified using the CAS website (Ichemistry.cn), and the known organic matter molecular formulas on the CAS website were identified. Organic matter molecular formulas with the same number of double bonds as the known organic matter molecular formulas were screened and grouped with the known organic matter molecular formulas. Based on the units where different molecular formulas in the same group differed, the different molecular formulas in the same group were used as points, and the different units were used as lines to connect the different points to obtain an organic matter molecular connection grid.

[0010] (3) Molecular structure recognition

[0011] In the organic matter molecular connection grid, by querying the molecular formula of known organic matter, the properties of the known organic matter corresponding to the molecular formula of the known organic matter are obtained, and the properties of different organic matter corresponding to different molecular formulas in the same group of organic matter are analyzed based on the properties of the known organic matter.

[0012] Preferably, in the above-mentioned method of coupling the chemical structure of organic molecules to an intelligent grid, the mass range of the organic molecular formula identified by the FT-ICR MS in step (1) is 200 to 800 Da.

[0013] Preferably, in the above-mentioned method of coupling the chemical structure of organic molecules to an intelligent grid, the specific process of screening in step (1) is:

[0014] First, exclude organic matter molecular formulas with Kendrick mass difference KMD>|1|, then exclude organic matter molecular formulas with H / C<1, and finally exclude organic matter molecular formulas with O / C>1.

[0015] Preferably, in the above-mentioned method for coupling the chemical structure of organic molecules to an intelligent grid, the step (2) further includes:

[0016] The screened organic matter molecular formulas are sorted from strong to weak according to peak intensity, and then identified through the CAS website.

[0017] Preferably, in the above-mentioned method of coupling the chemical structure of organic molecules to an intelligent grid, in the organic molecular connection grid in step (2), one or more of methylene, imino, hydrogen-phosphorus bond, oxygen, and sulfur are used as units for different molecular formulas in the same group of organic matter.

[0018] The present invention also provides an application of a method of coupling the chemical structure of organic matter molecules to an intelligent grid in detecting the source or migration and transformation of organic matter in ice and water media of lakes.

[0019] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention classifies soluble organic matter (DOM) by the number of double bonds, which can better analyze the properties of DOM. This breaks the limitation of the original FT-ICR MS that classifies organic matter by element type, and the analysis of DOM is no longer based solely on element type.

[0021] (2) The organic matter molecular connection grid described in the present invention is constructed by querying the molecular formula of known organic matter to obtain the properties of known organic matter corresponding to the molecular formula of known organic matter, and analyzing the properties of different organic matter corresponding to different molecular formulas in the same group of organic matter based on the properties of known organic matter; and combined with the analysis of microorganisms and environmental factors, the organic matter molecules can be analyzed at the molecular configuration level. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0023] Figure 1 This is the connection grid of organic matter molecules in ice and water in Example 1. DETAILED DESCRIPTION

[0024] The present invention provides a method for coupling the chemical structure of organic molecules to an intelligent grid, comprising the following steps:

[0025] (1) Data screening

[0026] Classify the organic matter molecular formulas corresponding to the organic matter mass spectrum peaks identified in FT-ICR MS, and then screen the obtained organic matter molecular formulas;

[0027] (2) Molecular formula sorting

[0028] The CAS website (Ichemistry.cn) was used to identify the molecular formulas of the screened organic matter, and the molecular formulas of the known organic matter on the CAS website were identified. The organic matter molecular formulas with the same number of double bonds as the known organic matter molecular formulas were screened and grouped with the known organic matter molecular formulas. Based on the units where different molecular formulas in the same group differed, the different molecular formulas in the same group were used as different points, and the different units were used as lines to connect the different points to obtain the organic matter molecular connection grid.

[0029] (3) Molecular structure recognition

[0030] In the organic matter molecular connection grid, by querying the molecular formula of known organic matter, the properties of the known organic matter corresponding to the molecular formula of the known organic matter are obtained, and the properties of different organic matter corresponding to different molecular formulas in the same group of organic matter are analyzed based on the properties of the known organic matter.

[0031] In the present invention, the FT-ICR MS data measurement process is as follows: using methanol as a solvent to dissolve the sample and then performing ultrasound, using an FT-ICR MS mass spectrometer to scan the entire sample spectrum; then using Beuker Daltonics software to analyze the molecular formula and the number of double bonds of the organic matter; the concentration of the dissolved sample is 100 mg / L, and the FT-ICR MS mass spectrometer is a Bruker 9.4T Apex Ultra FT-ICR MS, which is equipped with an Apollo II ESI ionization source and a 9.4T superconductor, and the ionization voltage is 3500V.

[0032] In the present invention, the mass range of the organic molecular formula identified by the FT-ICR MS in step (1) is preferably 200 to 800 Da, more preferably 300 to 700 Da, and even more preferably 400 to 600 Da.

[0033] In the present invention, the specific process of screening in step (1) is:

[0034] First, exclude organic matter formulas with Kendrick mass difference KMD>|1|, then exclude organic matter formulas with H / C<1, and finally exclude organic matter formulas with O / C>1. The reason for excluding organic matter formulas with H / C<1 is that such formulas have many double bonds and it is difficult to infer a valid configuration. The reason for excluding organic matter formulas with O / C>1 is that such formulas do not have a known configuration in CAS.

[0035] In the present invention, the step (2) further includes:

[0036] The screened organic matter molecular formulas are sorted from strong to weak according to peak intensity, and then identified through the CAS website.

[0037] In the present invention, the units with different molecular formulas in the organic matter molecular connection grid in step (2) are preferably one or more of methylene, imino, hydrogen-phosphorus bond, oxygen, and sulfur, more preferably methylene, imino or oxygen, and more preferably methylene or imino.

[0038] In the present invention, the starting point of the organic matter molecular connection grid is the molecular formula of the known organic matter that has been identified and verified.

[0039] In the present invention, in the organic molecule connection grid in step (2), the molecules that change with methylene (CH2) as the unit are the growth of the carbon chain. As the carbon chain grows, the fat solubility of the organic molecule increases; the molecules that change with oxygen (O) as the unit are the insertion of hydroxyl groups on the side groups of the molecules. The increase of hydroxyl groups enhances the water solubility of the molecules and enables the molecules to undergo esterification reactions. It may also be the insertion of ether bonds between carbon chains. The increase of ether bonds reduces the water solubility of the molecules and makes it easy to break from the ether bonds; the increase of imino (NH) units is mainly the insertion of amino groups on the side groups of the molecules. The increase of amino groups enhances the water solubility of the molecules and can produce condensation reactions with carboxyl groups; the increase of sulfur (S) units is the insertion of thiol groups on the side groups of the molecules. Thiol groups are more fat soluble than hydroxyl groups and are also more difficult to form hydrogen bonds. Two thiol groups can interact to form disulfide bonds, which often appear in proteins; the increase of hydrogen-phosphorus bond (HP) units is mainly the insertion of phosphate groups on the side groups of the molecules. Phosphate groups can further form phosphates or phospholipids.

[0040] In the present invention, Figure 1 Taking the lauryl sulfate group molecule as an example, the points in the organic molecule connection grid are respectively recorded as points A, B, and C, where point A represents the known organic molecule formula C identified in CAS. 12 H 25 O4S, the line connecting points A, B, and C represents a methylene group, then point B represents C which is one methylene away from point A. 11 H 23 O4S, point C represents a C that differs from point B by one methylene group 10 H 21 O4S.

[0041] The present invention also provides an application of a method for coupling the chemical structure of organic matter molecules to an intelligent grid in detecting the source or migration and transformation of organic matter in ice and water media of lakes.

[0042] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0043] Example 1

[0044] A method for coupling organic molecular chemical structures to an intelligent grid comprises the following steps:

[0045] (1) Water and ice samples from Wuliangsuhai Lake were used as samples. The specific collection process was as follows: 7 sampling points were set up on the lake, and 500 mL of water sample and 500 mL of ice sample (melt ice) were collected at each point for Fourier cyclotron resonance mass spectrometry (FT-ICRMS) determination;

[0046] The specific process of using the collected water sample for Fourier cyclotron resonance mass spectrometry is as follows:

[0047] The PPL column was washed and activated with 20 mL of methanol and 20 mL of acidified ultrapure water with a pH of 2, and impurities that may exist in the PPL column were removed at the same time.

[0048] Acidify 0.5L of water sample to pH 2, then pass it through the PPL column at a rate of 5mL / min. At this time, the organic matter in the water sample is adsorbed on the PPL column;

[0049] After the water sample passes through the PPL column, 20 mL of acidified ultrapure water with a pH of 2 is used to elute the PPL column to remove any salt that may remain on the PPL column.

[0050] After completely removing the moisture on the PPL column by nitrogen blowing, the organic matter adsorbed on the PPL column was eluted with 10 mL of methanol and stored in the dark at 4°C until analysis. Before measurement, it was dissolved in methanol and configured to a total organic carbon (TOC) concentration of 50 mg / L.

[0051] The specific process of using the collected ice sample (melted ice) for Fourier cyclotron resonance mass spectrometry is consistent with the specific process of using the collected water sample for Fourier cyclotron resonance mass spectrometry, the only difference being that the 0.5 L ice sample is first melted into water and then acidified to a pH of 2.

[0052] The parameters of the Fourier cyclotron resonance mass spectrometry (FT-ICR MS) measurement are as follows: the mass range of the collection is 200 to 800 Da, the ionization voltage is 3500 V, the injection rate is 180 μL / h, the acquisition mode is full spectrum, the number of sampling points is 2M, the number of spectrum averages is 128, the source accumulation time is 0.0010 s, the collision cell accumulation time is 0.2 s, the flight time is 1.3 ms, the ionization voltage is 3500 / 3000 V, the nebulizer gas flow rate is 2.0 L / min, the drying gas flow rate is 5.0 L / min, the drying gas temperature is 200°C, and the Q1mass is 280 m / z.

[0053] (2) Classify the organic molecular formulas corresponding to the organic mass spectral peaks identified by FT-ICR MS, and then screen the obtained organic molecular formulas in Excel software;

[0054] The specific process of the screening is: first, exclude organic molecular formulas with Kendrick mass difference KMD>|1|, then exclude organic molecular formulas with H / C<1, and finally exclude organic molecular formulas with O / C>1;

[0055] (3) Using the CAS website to identify the molecular formulas of the screened organic matter, identify the molecular formulas of the known organic matter on the CAS website; screen out the molecular formulas of the organic matter with the same number of double bonds as the molecular formulas of the known organic matter, and classify them into the same group of organic matter as the molecular formulas of the known organic matter; according to the units that differ from different molecular formulas in the same group of organic matter, take the identified molecular formula of the known organic matter as the starting point, take the different molecular formulas in the same group of organic matter as different points, and take the differing units as lines to connect the different points through lines to obtain an organic matter molecular connection grid; in the organic matter molecular connection grid, the differing units increase from left to right and decrease from top to bottom; the differing units are methylene, imino, hydrogen-phosphorus bond, oxygen, and sulfur, respectively, with blue lines representing methylene, red lines representing oxygen, green lines representing sulfur, yellow lines representing imino, and purple lines representing hydrogen-phosphorus bond;

[0056] The molecular formulas of the known organic matter identified on the CAS website are:

[0057] Lauryl sulfate ion, molecular formula is C 12 H 25 O4S - , is a nutritional supplement that mainly comes from the input of exogenous organic matter. The molecules in the same group as the organic matter molecules all change with CH2 as the unit, and there are fewer species in ice and water;

[0058] Tetrapropenylbenzenesulfonate ion, molecular formula C 18 H 29 O3S - , easily combined with sodium ions to form a water treatment adsorbent, and the molecules in the same group as the organic matter change with CH2 and O as units, which is the growth of the carbon chain and the insertion of hydroxyl groups on the side groups;

[0059] Octyl gallate, molecular formula C 15 H 22 O5, often used as an antioxidant, is also an exogenous organic matter input into the lake. The molecules in the same group as this organic matter change with CH2, O and NH as units, which is the growth of carbon chain and the insertion of hydroxyl and amino groups.

[0060] Stearate ion, molecular formula C 18 H 35 O2 -Stearic acid is commonly found in natural fatty substances. The molecules in the same group as this organic matter vary with CH2, O, HP and S as units. The changes in CH2 and O units are the growth of carbon chains and the insertion of hydroxyl groups. Meanwhile, the changes in HP and S units are mainly the elements inserted into fats formed by stearic acid.

[0061] 2-Adamantyl succinic acid monoethyl ester, molecular formula C 16 H 21 O4 is an ester formed by the esterification of hydroxyl-containing organic matter with succinic acid. The molecules in the same group as the organic matter vary with CH2, O, NH and S as units. Succinic acid is a common organic matter in animal and plant tissues. As a stable basic unit, succinic acid esterifies with different organic matter, resulting in a variety of unit changes.

[0062] Phenyl-1-thiol-β-D-galactoside, molecular formula C 12 H 16 O5S, an organic matter, is a metabolic intermediate of sugars and is related to microorganisms in lakes that metabolize sugars. The molecules in the same group as this organic matter vary in units of CH2, O, and NH. It is an intermediate product produced by the metabolism of different sugars, resulting in differences in molecular formulas.

[0063] Myristicin, molecular formula C 15 H 18 O8, this type of glycoside is mainly formed by the condensation of sugars secreted by sweet clover with other organic matter. The molecules in the same group as the organic matter vary with CH2, O, NH, S and HP as units. This is mainly because the sugars secreted by sweet clover can condense with a variety of organic matter, so the molecular composition of this group of organic matter is relatively complex.

[0064] (4) The properties of seven groups of organic molecules common to ice and water were analyzed, and combined with microbial data, the following conclusions were drawn:

[0065] Sodium tetrapropylene benzene sulfonate, as an adsorbent, is an organic matter component introduced during sample pretreatment;

[0066] The main organic molecules identified are CHO molecules, and the insertion of other units is the combination of functional groups on the side groups, which has an impact on the hydrophilic and hydrophobic properties;

[0067] Among the identified organic matter, those related to microbial metabolism and plant secretions were analyzed, proving that the sources of organic matter in the lake are mainly related to the metabolism of lake microorganisms and secretions of coastal plants.

[0068] Among the identified organic matter, several groups of organic matter grids, such as 2-adamantyl succinate monoethyl ester and myristicin, all have CHO molecules combined with NH, S, and HP units to transform into CHNO, CHOS, CHOP and other molecules, which can reflect the migration and transformation process of organic matter molecules.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for coupling organic molecular chemical structure to intelligent grid, characterized in that: The following steps are involved: (1) Data screening Classify the organic matter molecular formulas corresponding to the organic matter mass spectrum peaks identified in FT-ICR MS, and then screen the obtained organic matter molecular formulas; (2) Molecular formula sorting The CAS website was used to identify the molecular formulas of the screened organic matter, and the molecular formulas of the known organic matter on the CAS website were identified; the molecular formulas of the organic matter with the same number of double bonds as the known organic matter were screened and grouped into the same group as the known organic matter molecular formulas; based on the units with different molecular formulas in the same group of organic matter, the different molecular formulas in the same group of organic matter were used as different points, and the different units were used as lines to connect the different points to obtain the organic matter molecular connection grid; (3) Molecular structure recognition In the organic matter molecular connection grid, by querying the molecular formula of known organic matter, the properties of the known organic matter corresponding to the molecular formula of the known organic matter are obtained. Based on the properties of the known organic matter, the properties of different organic matter corresponding to different molecular formulas in the same group of organic matter are analyzed; The mass range of the organic molecular formula identified by the FT-ICR MS in step (1) is 200-800 Da; The specific process of screening in step (1) is as follows: First, exclude organic matter formulas with Kendrick mass difference (KMD) > |1|, then exclude organic matter formulas with H / C < 1, and finally exclude organic matter formulas with O / C > 1. In the organic matter molecular connection grid in step (2), one or more of methylene, imino, hydrogen-phosphorus bond, oxygen, and sulfur are used as units for different molecular formulas in the same group of organic matter.

2. The method for coupling organic molecular chemical structure to intelligent grid according to claim 1, characterized in that: The step (2) also includes the following steps before identification: The screened organic matter molecular formulas are sorted from strong to weak according to peak intensity, and then identified through the CAS website.

3. Application of the method of coupling the organic matter molecular chemical structure with the intelligent grid as described in claim 1 or 2 to detecting the source or migration and transformation of organic matter in ice and water media of lakes.

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