CN212483475U

CN212483475U - Instrument for synchronously representing physicochemical/optical characteristics of organic matter to be detected

Info

Publication number: CN212483475U
Application number: CN202021072240.XU
Authority: CN
Inventors: 黎雷; 张文俊
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2020-06-11
Filing date: 2020-06-11
Publication date: 2021-02-05
Anticipated expiration: 2030-06-11

Abstract

The utility model relates to an instrument for synchronously representing physicochemical/optical characteristics of organic matters to be detected, which comprises a separation system, an online pretreatment system and a detection system, wherein the separation system comprises an automatic sample injector, an SEC chromatographic column, a switching valve and an HIC chromatographic column which are connected in sequence, the SEC chromatographic column is used for realizing the sequential separation of samples to be detected according to the molecular weight, and the HIC chromatographic column is used for realizing the separation of the samples to be detected according to the hydrophilic-hydrophobic property; the online pretreatment system comprises an injection valve, an inorganic carbon remover and an ultraviolet digestion device, and the detection system comprises an ultraviolet detector, a three-dimensional fluorescence detector, an organic carbon detector and an organic nitrogen detector; according to the flow path direction of a sample to be detected, the HIC chromatographic column is sequentially connected with an ultraviolet detector, a three-dimensional fluorescence detector, an injection valve, an inorganic carbon remover, an ultraviolet digestion device, an organic carbon detector and an organic nitrogen detector. The utility model discloses can be used to aspects such as DBPs precursor discernment, absorption competition mechanism research, membrane pollutant prediction and biochemical organic carbon/nitrogen detection.

Description

Instrument for synchronously representing physicochemical/optical characteristics of organic matter to be detected

Technical Field

The utility model belongs to the technical field of the environmental detection, a synchronous sign organic matter physics and chemistry/optical characteristics's that awaits measuring instrument is related to.

Background

Pollutants in surface water sources generally mainly comprise organic matters, wherein the treatment difficulty of Dissolved Organic Matters (DOM) is high, and the key to influence the quality of the water leaving a factory is also the problem. DOM presents many hazards to drinking water treatment, such as can make raw water appear colour, smell even toxic and side effect, reduces membrane filtration and carbon filtration effect, causes membrane blockage and active carbon adsorption capacity reduction, reduces the performance of oxidant and disinfectant etc.. Therefore, the removal rate of DOM should be increased as much as possible in the water treatment process, which necessitates a thorough understanding of the composition characteristics of DOM and the migration and transformation rules thereof in the water treatment process (single or combined). Because DOM is a complex and heterogeneous mixture, it is necessary to classify DOM physico-chemically (e.g., classifying according to molecular weight and hydrophilicity and hydrophobicity) and then detect the relevant characteristic parameters of its separation components in order to comprehensively reflect the physico-chemical (concentration/molecular weight/hydrophilicity) and optical characteristics (ultraviolet absorption/fluorescence) of DOM. In recent years, Size Exclusion Chromatography (SEC) and Hydrophobic Interaction Chromatography (HIC) are widely used for stepless separation of molecular weight and hydrophilicity and hydrophobicity of unknown samples due to the advantages of convenient operation, almost no damage and high-efficiency and accurate separation, and the characterization of DOM physicochemical/optical characteristics can be realized by performing multi-detector system detection on separated components.

Since the DOC-Labor laboratory developed the separation and joint characterization of DOM different molecular weight components based on SEC (also known as LC-OCD-OND), based on the separation of UV detector (UVD), Organic Carbon Detector (OCD) and Organic Nitrogen Detector (OND), the study is called "Characterisation of aqueous and non-micromatrix with size-exclusion chromatography-organic carbon-detection-organic nitrogen-detection" (LC-OCD-OND), Water Research, 2011, the waterworks gradually recognized that the characterization of DOM technology by the combination of multiple detectors had great promise. Patent CN 201710097221.9 discloses a method for quantitative detection of DOM by collecting fluorescence multi-emission three-dimensional spectral data of each component after DOM is separated by SEC. According to the method, the DOM with different molecular weights are roughly divided into humus substances, amino acid substances and non-humus substances, but due to the lack of a concentration detector (OCD or OND and the like), the accuracy of quantitative detection of the DOM is insufficient. Patent CN201811466516.X discloses a method and a device for online detection of DOM (document object model) by organic nitrogen and organic carbon in series, the device is similar to LC-OCD-OND, can realize synchronous detection of organic carbon and organic nitrogen concentrations of components with different molecular weights, but lacks other key detection parameter information such as fluorescence, and meanwhile, no solution is provided for the problem of background nitrate ion interference in water, which has a large influence on Detection of Organic Nitrogen (DON). The invention patent CN201910382778.6 and the utility model patent ZL 201920655954.4 recently disclosed/granted by the inventor of the present application use a multi-detector synchronous characterization system to perform ultraviolet absorption, three-dimensional fluorescence, synchronous detection of organic carbon and organic nitrogen concentration characteristics (SEC-UVD/3 deep/OCD/OND) on DOM components separated by SEC, and separate nitrate ions with large interference on DON detection by using tandem OND.

In 1994, Fuchs et al used a Hydrophobic Interaction Chromatography (HIC) for the first time for humus separation and performed simultaneous detection of uv and organic carbon concentrations, which gave a satisfactory separation characterization and indicated that the combined use of different chromatographic separation methods (i.e. multidimensional liquid Chromatography) has promise for DOM Analysis-by-synthesis (see: Application of Hydrophobic Interaction Chromatography (HIC) in Water Analysis, Clean-Soil Air Water, 1994). HIC utilizes different hydrophilic and hydrophobic substances to have different hydrophobic adsorption strengths with fillers under different ionic strengths, and sequentially separates the different hydrophilic and hydrophobic substances by changing the ionic strength of a mobile phase in a gradient manner. HIC is mostly used for separating and purifying protein substances in the industries of medicine, food and the like, but is rarely applied in the field of environmental detection. Multi-dimensional liquid chromatography (generally, two-dimensional liquid chromatography) refers to a series of detections performed after a sample is subjected to multiple independent separations by chromatographic columns of different modes, and can provide column capacity and detection information which are several times of those of common one-dimensional liquid chromatography. Patents CN201711357830.x and CN201510832550.4 both disclose a method for purifying kallikrein by using HIC, which provides a reference example for the application of HIC in the technical field of environmental detection. ZL 201310365709.7 discloses a chromatographic system with multi-color chromatographic columns connected in series, which consists of a separation system and a detection system, wherein various chromatographic columns in the separation system can be selected from a normal phase chromatographic column, a reverse phase chromatographic column, a gel chromatographic column, a hydrophobic chromatographic column or an ion exchange chromatographic column; the detection system consists of a UV detector, a pH detector and a conductivity detector. The above system constitutes a rudiment of a multidimensional liquid chromatography system, but has the disadvantages that: (1) the system realizes multidimensional separation by connecting a plurality of four-way valves or three-way valves in series with chromatographic columns, has a complex structure and influences the stability of the system; (2) the subsequent detectors lack quantitative detectors (OCD or OND, etc.) and fluorescence detectors, and the accuracy of the quantification of the separated components is insufficient; (3) the above-described system does not provide any information (indicated only by "reservoir") about the mobile phase, which is relevant to the type of column, the type of detector, and the nature of the separated water sample, and is of great importance in the development of a particular chromatographic separation method and apparatus; (4) the system is mainly used in chromatography, and is not suitable for the mainstream high performance liquid chromatography at present. Patent ZL 201010256470.6 discloses a full two-dimensional ultra-high pressure high performance liquid chromatography separation system, which focuses on the design and operation method of a two-position ten-way valve system in the separation, and shows that two-dimensional liquid chromatography can be realized by a laboratory device, but the application of the two-dimensional liquid chromatography is not further described. In the aspect of specific application of two-dimensional liquid chromatography, patents CN202010086190.9, CN201911112232.5, cn201911051738.x and CN201810857019.6 all disclose a method for separating a single component (such as a target protein, NNK, sucrose ester and the like) by using two-dimensional liquid chromatography in combination with a single detector (such as an ultraviolet detector, a mass spectrometer and the like), which indicates that the two-dimensional liquid chromatography has a mature application in industries such as food, medicine and chemical analysis, but in the field of environmental detection technology, particularly detection of DOM, no patent report is found.

In summary, the main problems of the current DOM characterization methods are: (1) the detection information provided by the common one-dimensional liquid chromatography is limited, and the analysis requirements of increasingly complex DOM components cannot be met; (2) a multi-detector combined characterization method based on SEC or HIC separation cannot synchronously characterize the physicochemical/optical characteristics of DOM components with different molecular weights/hydrophilicity and hydrophobicity, and the problem of detection interference of inorganic nitrogen ions on DON is not solved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an instrument of synchronous sign organic matter physicochemical optical characteristic that awaits measuring particularly, is to provide an instrument of synchronous sign different molecular weight/hydrophilicity hydrophobicity dissolubility organic matter physicochemical optical characteristic.

The utility model discloses synchronous characterization organic matter physicochemical optical property's that awaits measuring instrument utilizes full two-dimensional liquid chromatogram to carry out two-dimentional quadrature separation to the DOM, full two-dimensional liquid chromatogram indicates Size Exclusion Chromatogram (SEC) to separate for the first dimension, hydrophobic nature effect chromatogram (HIC) is the second dimension separation, then utilize many detecting system to include ultraviolet detector UVD, three-dimensional fluorescence detector 3DEEMD, organic carbon detector OCD and organic nitrogen detector OND carry out physicochemical property and the synchronous characterization of optical property to the DOM.

The physical and chemical properties of the DOM comprise concentration, molecular weight and hydrophilicity and hydrophobicity, and the optical properties of the DOM comprise ultraviolet light absorption properties and fluorescence properties.

Wherein the first-dimensional separation may also be referred to as one-dimensional SEC or LC₁SEC, the second dimension separation also being referred to as two-dimensional HIC or LC₂-HIC, a two-dimensional liquid chromatography also known as SEC × HIC.

The purpose of the utility model can be realized through the following technical scheme:

the utility model provides an instrument for synchronously representing the physicochemical/optical characteristics of organic matters to be detected, which comprises a separation system, an on-line pretreatment system and a detection system,

the separation system comprises an automatic sample injector, an SEC chromatographic column, a switching valve and an HIC chromatographic column which are sequentially connected according to the flow path direction of a sample to be detected, wherein the automatic sample injector is used for receiving the sample to be detected, the SEC chromatographic column is used for realizing sequential separation of the sample to be detected according to the molecular weight, and the HIC chromatographic column is used for realizing separation of the sample to be detected according to the hydrophilic-hydrophobic property;

the on-line pretreatment system comprises an injection valve, an inorganic carbon remover and an ultraviolet digester,

the detection system comprises an ultraviolet detector, a three-dimensional fluorescence detector, an organic carbon detector and an organic nitrogen detector;

and according to the flow path direction of a sample to be detected, the HIC chromatographic column is sequentially connected with an ultraviolet detector, a three-dimensional fluorescence detector, an injection valve, an inorganic carbon remover, an ultraviolet digestion device, an organic carbon detector and an organic nitrogen detector.

The utility model discloses an in an embodiment, piece-rate system still includes the SEC mobile phase and SEC transfer pump, the SEC mobile phase pass through the SEC transfer pump with the autosampler is connected, the SEC mobile phase is carried extremely by the SEC transfer pump the autosampler.

The utility model discloses an in an embodiment, piece-rate system still includes HIC mobile phase and HIC transfer pump, HIC mobile phase pass through HIC transfer pump with the diverter valve is connected, HIC mobile phase is carried to by HIC transfer pump the diverter valve.

In one embodiment of the present invention, the switching valve comprises 5 ports and 2 quantitative rings, wherein the 5 ports are respectively a first port, a second port, a third port, a fourth port, and a fifth port, and the 2 quantitative rings are respectively a first quantitative ring and a second quantitative ring,

the switching valve has two working states,

when the first quantitative ring is not fully loaded, the switching valve is in the first working state,

the SEC chromatographic column, the first interface, the second interface, the first quantitative ring and the fifth interface are sequentially communicated,

the HIC infusion pump, the fifth interface, the second quantitative ring, the fourth interface, the third interface and the HIC chromatographic column are sequentially communicated,

the components separated from the SEC chromatographic column enter a first interface, then enter a first quantitative ring through a second interface, are mixed with an HIC mobile phase conveyed by an HIC infusion pump at a fifth interface, and then enter the HIC chromatographic column through the second quantitative ring, a fourth interface and a third interface;

when the first fixed ring is fully loaded, the switching valve is in the second working state,

the SEC chromatographic column, the first interface, the fourth interface, the second quantitative ring and the fifth interface are sequentially communicated,

the HIC infusion pump, the fifth interface, the first quantitative ring, the second interface, the third interface and the HIC chromatographic column are sequentially communicated,

liquid flow from the HIC infusion pump enters a first quantitative ring, and then the full-loaded SEC component is completely sent into the HIC chromatographic column through a second interface and a third interface; meanwhile, the first interface is communicated with the fourth interface, and the components separated from the SEC chromatographic column enter the second quantitative ring for storage.

This is repeated and the fractions separated by the SEC column are transferred in their entirety to the HIC column for further separation.

In one embodiment of the present invention, the volume of the first quantitative ring is preferably 5 to 15 mL.

In an embodiment of the present invention, the fifth interface further comprises a waste liquid outlet, and the reason for setting the waste liquid outlet is to prevent the first quantitative ring from overflowing in an accident situation.

In one embodiment of the present invention, the SEC column packing is preferably HW-50S packing from TOYOPEARL, Inc.

In one embodiment of the present invention, the HIC column is preferably a TSKgel Butyl-NPR column from TOYOPEARL corporation.

In one embodiment of the present invention, the on-line pretreatment system further comprises an acidifying agent and an oxidizing agent, both of which are connected to the injection valve.

In an embodiment of the present invention, the ultraviolet digestion device includes a metal casing, a low-pressure mercury lamp and a spiral quartz tube, the low-pressure mercury lamp and the spiral quartz tube are both located in the metal casing, and the spiral quartz tube is sleeved outside the low-pressure mercury lamp.

In one embodiment of the present invention, the metal shell is preferably made of stainless steel, and is corrosion resistant; the low-pressure mercury lamp is designed to be a double low-pressure mercury lamp oxidation device, so that the oxidation efficiency is ensured to the maximum extent; the inner diameter of the spiral quartz tube is preferably 0.5-1.5 mm, the outer diameter of the spiral is preferably 1.5-2.0 cm, and the length of the spiral is preferably 10-20 m.

In one embodiment of the present invention, the injection valve is preferably a circular injection valve with no dead volume, short mixing time, corrosion resistance and high pressure resistance, and the valve can fully mix the sample flow and the oxidant and then enter the uv digestion device.

In one embodiment of the present invention, the inorganic carbon remover is preferably a commercial degassing module.

In an embodiment of the present invention, the ultraviolet detector, the three-dimensional fluorescence detector, the organic carbon detector, and the organic nitrogen detector are all connected to a data acquisition computer.

The utility model discloses in, the ultraviolet detector is used for detecting separation component ultraviolet absorption characteristic.

The three-dimensional fluorescence detector is used for detecting the fluorescence characteristics of the separated components.

The organic carbon detector is used for detecting the concentration of the organic carbon in the separated components.

The organic nitrogen detector is used for detecting the concentration of the organic nitrogen in the separation component.

In one embodiment of the present invention, the data acquisition computer is used for acquiring data of the ultraviolet detector, the three-dimensional fluorescence detector, the organic carbon detector, and the organic nitrogen detector.

The utility model provides an aspect such as disinfection accessory Substance (DBPs) precursor discernment, absorption competition mechanism research, membrane pollutant prediction and biochemical organic carbon/nitrogen detection that the instrument can be used to the environmental detection field.

Compared with the prior art, the utility model discloses an instrument can realize the synchronous/nondestructive test of different molecular weight/hydrophilicity and hydrophobicity DOM physics and chemistry (concentration/molecular weight/hydrophilicity and hydrophobicity) and optics (ultraviolet absorption/fluorescence characteristic) characteristic.

On the other hand, the utility model discloses in, HIC has splendid separation effect to aquatic inorganic ion, consequently can effectively separate micromolecule DON and DIN, can avoid the interference of aquatic background DIN to DON detection to the realization is to the accurate detection of DON.

Drawings

Fig. 1 is a system flow chart of an instrument for synchronously characterizing physicochemical/optical characteristics of organic matter to be measured according to an embodiment of the present invention;

FIG. 2 is a schematic view of a first operating state of the switching valve;

FIG. 3 is a schematic view of a second operating state of the switching valve;

FIG. 4 is a schematic diagram of the internal structure of the ultraviolet detector;

FIG. 5 is a schematic diagram showing the raw water detection chromatogram of a certain water source in Suzhou Taihu lake in example 1;

FIG. 6 is a DON content quantitative matrix schematic diagram of DOM with different molecular weights/hydrophilicity and hydrophobicity, obtained by extracting color data of a raw water detection chromatogram of a certain water source in Suzhou Taihu lake in example 1.

The reference numbers in the figures indicate:

1 a separation system; 1-1SEC mobile phase; 1-2SEC infusion pump; 1-3 automatic sample injector; 1-4SEC chromatographic columns; 1-5 switching valves; 1-6HIC mobile phase; 1-7HIC infusion pump; 1-8HIC chromatography column 2 on-line pretreatment system; 2-1 acidifying agent; 2-2 oxidizing agent; 2-3 injection valves; 2-4 inorganic carbon removers; 2-5 ultraviolet digestion devices;

3, detecting a system; 3-1 ultraviolet detector; 3-2 three-dimensional fluorescence detectors; 3-3 organic carbon detector; 3-4 organic nitrogen detector; 3-5, a data acquisition computer;

1-5-1 to 1-5-5 are different interfaces respectively; 1-5-6 first quantitative rings, 1-5-7 second quantitative rings;

2-5-1 metal housing; 2-5-2 low-pressure mercury lamps; 2-5-3 quartz spiral tube.

Detailed Description

Referring to fig. 1, the utility model provides an instrument for synchronously representing physicochemical/optical characteristics of organic matter to be detected, including a separation system 1, an online pretreatment system 2 and a detection system 3, the separation system 1 includes an automatic sample injector 1-3, an SEC chromatographic column 1-4, a switching valve 1-5, and an HIC chromatographic column 1-8 which are connected in sequence according to the flow path direction of a sample to be detected, the automatic sample injector 1-3 is used for receiving the sample to be detected, the SEC chromatographic column 1-4 is used for realizing that the sample to be detected is separated in sequence according to molecular weight, the HIC chromatographic column 1-8 is used for realizing that the sample to be detected is separated according to hydrophilicity and hydrophobicity; the online pretreatment system 2 comprises an injection valve 2-3, an inorganic carbon remover 2-4 and an ultraviolet digestion device 2-5, and the detection system 3 comprises an ultraviolet detector 3-1, a three-dimensional fluorescence detector 3-2, an organic carbon detector 3-3 and an organic nitrogen detector 3-4; according to the flow path direction of a sample to be detected, the HIC chromatographic column 1-8 is sequentially connected with an ultraviolet detector 3-1, a three-dimensional fluorescence detector 3-2, an injection valve 2-3, an inorganic carbon remover 2-4, an ultraviolet digester 2-5, an organic carbon detector 3-3 and an organic nitrogen detector 3-4.

With further reference to fig. 1, in an embodiment of the present invention, the separation system 1 further includes an SEC mobile phase 1-1 and an SEC infusion pump 1-2, the SEC mobile phase 1-1 is connected to the autosampler 1-3 through the SEC infusion pump 1-2, and the SEC mobile phase 1-1 is transported to the autosampler 1-3 by the SEC infusion pump 1-2.

With further reference to fig. 1, in an embodiment of the present invention, the separation system 1 further includes HIC mobile phases 1-6 and HIC infusion pumps 1-7, the HIC mobile phases 1-6 are connected to the switching valves 1-5 through HIC infusion pumps 1-7, and the HIC mobile phases 1-6 are delivered to the switching valves 1-5 by HIC infusion pumps 1-7.

With further reference to fig. 2 and 3, in an embodiment of the present invention, the switching valve 1-5 includes 5 connectors and 2 quantitative rings, the 5 connectors are a first connector 1-5-1, a second connector 1-5-2, a third connector 1-5-3, a fourth connector 1-5-4, and a fifth connector 1-5-5, the 2 quantitative rings are a first quantitative ring 1-5-6 and a second quantitative ring 1-5-7,

the switching valves 1-5 have two operating states,

when the first quantitative ring 1-5-6 is not fully loaded, the switching valve 1-5 is in a first working state, at the time, the SEC chromatographic column 1-4, the first interface 1-5-1, the second interface 1-5-2, the first quantitative ring 1-5-6 and the fifth interface 1-5-5 are sequentially communicated, the HIC infusion pump 1-7, the fifth interface 1-5-5, the second quantitative ring 1-5-7, the fourth interface 1-5-4, the third interface 1-5-3 and the HIC chromatographic column 1-8 are sequentially communicated, components separated from the SEC chromatographic column 1-4 enter the first interface 1-5-1, and then enter the first quantitative ring 1-5-6 through the second interface 1-5-2, then mixing the mixture with an HIC mobile phase conveyed by an HIC infusion pump 1-7 at a fifth interface 1-5-5, and then entering an HIC chromatographic column 1-8 through a second quantitative ring 1-5-7, a fourth interface 1-5-4 and a third interface 1-5-3;

when the first quantitative ring 1-5-6 is fully loaded, the switching valve 1-5 is in a second working state, at this time, the SEC chromatographic column 1-4, the first interface 1-5-1, the fourth interface 1-5-4, the second quantitative ring 1-5-7 and the fifth interface 1-5-5 are sequentially communicated, the HIC infusion pump 1-7, the fifth interface 1-5-5, the first quantitative ring 1-5-6, the second interface 1-5-2, the third interface 1-5-3 and the HIC chromatographic column 1-8 are sequentially communicated, liquid flow from the HIC infusion pump 1-7 enters the first quantitative ring 1-5-6, then the full-load SEC component is sent into an HIC chromatographic column 1-8 through a second interface 1-5-2 and a third interface 1-5-3; meanwhile, the first interface 1-5-1 is communicated with the fourth interface 1-5-4, and the components separated from the SEC chromatographic column 1-4 enter the second quantitative ring 1-5-7 for storage.

This is repeated and the fractions separated by SEC columns 1-4 are all transferred to HIC columns 1-8 for further separation.

In one embodiment of the present invention, the volume of the first quantitative ring 1-5-6 is preferably 5-15 mL.

In one embodiment of the present invention, the fifth interface 1-5-5 is further provided with a waste liquid outlet, which is set for preventing the first quantitative ring 1-5-6 from overflowing in an accident situation.

In one embodiment of the present invention, the SEC columns 1-4 packing is preferably TOYOPEARL HW-50S packing.

In one embodiment of the present invention, the HIC column 1-8 is preferably a TOYOPEARL TSKgel Butyl-NPR column.

With further reference to fig. 1, in one embodiment of the present invention, the on-line pretreatment system further comprises an acidifying agent 2-1 and an oxidizing agent 2-2, wherein the acidifying agent 2-1 and the oxidizing agent 2-2 are both connected to an injection valve 2-3.

With further reference to fig. 4, in an embodiment of the present invention, the ultraviolet sterilizer 2-5 includes a metal casing 2-5-1, a low-pressure mercury lamp 2-5-2, and a spiral quartz tube 2-5-3, wherein the low-pressure mercury lamp 2-5-2 and the spiral quartz tube 2-5-3 are both located inside the metal casing 2-5-1, and the spiral quartz tube 2-5-3 is sleeved outside the low-pressure mercury lamp 2-5-2.

With further reference to fig. 4, the metal casing 2-5-1 is preferably made of stainless steel and is corrosion resistant; the low-pressure mercury lamp 2-5-2 is designed to be arranged for double low-pressure mercury lamp oxidation, so that the oxidation efficiency is ensured to the maximum extent; the inner diameter of the spiral quartz tube is preferably 0.5-1.5 mm in 2-5-3, the outer diameter of the spiral is preferably 1.5-2.0 cm, and the length is preferably 10-20 m.

In one embodiment of the present invention, the injection valves 2-3 are preferably circular injection valves with no dead volume, short mixing time, corrosion resistance, and high pressure resistance, which can fully mix the sample flow and the oxidant before entering the uv digestion device.

In one embodiment of the present invention, the inorganic carbon removers 2 to 4 are preferably commercialized degassing modules.

In one embodiment of the present invention, the ultraviolet detector 3-1, the three-dimensional fluorescence detector 3-2, the organic carbon detector 3-3, and the organic nitrogen detector 3-4 are all connected to a data acquisition computer 3-5.

In the utility model discloses, ultraviolet detector 3-1 is used for detecting separation component ultraviolet absorption characteristic.

The three-dimensional fluorescence detector 3-2 is used to detect the fluorescence properties of the separated components.

The organic carbon detector 3-3 is used for detecting the concentration of the organic carbon in the separation component.

The organic nitrogen detector 3-4 is used for detecting the concentration of the organic nitrogen in the separation component.

In one embodiment of the present invention, the data acquisition computer 3-5 is used for acquiring data of the ultraviolet detector 3-1, the three-dimensional fluorescence detector 3-2, the organic carbon detector 3-3, and the organic nitrogen detector 3-4.

Referring to fig. 1, the present invention further provides an apparatus for synchronously characterizing physicochemical/optical properties of organic matter to be measured, a method for synchronously characterizing physicochemical/optical properties of organic matter to be measured, comprising the following steps:

s1, in SEC flow: the SEC mobile phase 1-1 is conveyed to an autosampler 1-3 by an SEC infusion pump 1-2, a sample is injected into a flow path by the autosampler 1-3, the sample flow is sequentially separated according to molecular weight in an SEC chromatographic column 1-4, and then components with different molecular weights enter a switching valve 1-5;

s2, in HIC flow path: the HIC mobile phase 1-6 is conveyed to a switching valve 1-5 through an HIC infusion pump 1-7;

s3, in switching valves 1 to 5: through the flow path switching of the switching valve 1-5, all DOM components with different molecular weights are conveyed to an HIC chromatographic column 1-8 from an HIC mobile phase, and are further separated according to the hydrophilic and hydrophobic properties;

s4, enabling the sample flow to further enter an ultraviolet detector 3-1 for detecting ultraviolet light absorption characteristics, enabling the sample flow to enter a three-dimensional fluorescence detector 3-2 for detecting/fluorescence characteristics, then injecting an acidifier 2-1 and an oxidant 2-2, fully mixing the acidifier and the oxidant in an injection valve 2-3, enabling the sample flow to enter an inorganic carbon remover 2-4 for removing background carbon dioxide in water, enabling the sample flow to enter an ultraviolet digester 2-5 for fully oxidizing, and respectively converting DOC and DON into CO₂And nitrate ion, and detecting the content of the nitrate ion by a subsequent organic carbon detector 3-3 and an organic nitrogen detector 3-4, respectively, and finally passing CO₂And nitrate ion content reversed to DOC and DON content.

In one embodiment of the present invention, the SEC mobile phase 1-1 is preferably a phosphate buffer solution prepared using ultrapure water. Further, the concentration of the phosphate buffer solution is preferably 4mM, and the pH is 6.8. The SEC mobile phase 1-1 ionic strength is important for the SEC to accurately separate DOM according to the molecular weight, and is generally related to the type of a SEC chromatographic column packing, the type of a separated sample and the high salt concentration tolerance of a subsequent OCD detector, and through a large amount of experimental demonstration, the applicant preferably selects the SEC mobile phase 1-1 ionic strength to be 0.05-0.5 mol/L when HW-50S packing of TOYOPEARL company is used as the packing of the SEC chromatographic column 1-4.

In one embodiment of the present invention, the ionic strength of the SEC mobile phase 1-1 can be adjusted using sodium sulfate.

The utility model discloses an in an embodiment, 1-2 velocity of flow of SEC transfer pump need with entire system adaptation, when guaranteeing DOM in the SEC fully separate, guarantee again that the SEC sample flow is whole to be shifted to the HIC flow path in, the applicant demonstrates through a large amount of experiments, the preferred 1.0 ~ 5.0mL/min of velocity of flow of SEC transfer pump 1-2, the elution time is 100 ~ 150 min.

In an embodiment of the present invention, to ensure the detection accuracy, the sample amount of the automatic sample injector 1-3 is preferably 1.0-10.0 mL.

In one embodiment of the present invention, the SEC columns 1 to 4 are used as a pretreatment column, preferably a preparative column, of the HIC column, and can bear a large volume sample injection amount to ensure the accuracy of subsequent HIC separation. The applicant has made extensive experimental demonstrations that, finally, the SEC columns 1-4 packing is preferably HW-50S packing of TOYOPEARL company, which has an excellent separation effect on DOM and is suitable for use in the present apparatus.

In one embodiment of the present invention, the HIC mobile phases 1-6 serve as carriers for different SEC components and need to be compatible with the SEC sample stream; and simultaneously meets the requirements of HIC gradient elution. The applicant has demonstrated through a large number of experiments that the preferred HIC mobile phase is phase a: high ionic strength phosphate buffer, phase B: pure phosphate buffer solution (concentration 4mM, pH 6.8). Further preferably, the ionic strength of the phase A is adjusted to be 0.5-5 mol/L by using sodium sulfate.

In one embodiment of the present invention, the flow rate of the HIC infusion pump 1 to 7 is such that: first, the SEC component is transferred in its entirety to the HIC; second, the time for HIC analysis was shortened as much as possible. It is related to SEC infusion pump flow rate, sample volume and type of sample isolated. Through a large amount of experimental demonstration, the applicant prefers that the flow rate of 1-7 of the HIC infusion pump is 1-3 mL/min on the premise of meeting the setting of other instrument parameters of the system; the elution gradient was: 0-1 min: 100-0% of phase A and 0-100% of phase B; 1-1.5 min: phase A0%, phase B100%; 1.5-2 min: 100% of phase A and 0% of phase B.

In one embodiment of the present invention, the HIC chromatography columns 1-8 are capable of withstanding extreme column pressures and flow rates, and the analysis time should be as short as possible. Through a large amount of experimental demonstration, the HIC chromatographic columns 1 to 8 are preferably TSKgel Butyl-NPR chromatographic columns of TOYOPEARL corporation, which have the greatest advantage of loading Butyl as a filler, so that the HIC chromatographic columns are suitable for organic matter analysis of general natural surface water bodies. Meanwhile, the packing can bear higher pressure and flow rate and is suitable for the analysis condition of the instrument.

In one embodiment of the present invention, the acidulant 2-1 is preferably a 6M phosphoric acid solution.

In one embodiment of the present invention, the oxidizing agent 2-2 is preferably 1 to 5mM potassium persulfate solution.

Preferably, in the above method, each detector signal is acquired by a data acquisition computer 3-5.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Examples

Raw water of a certain place of the Taihu lake in Suzhou city is used as a detection object.

The results of the analysis of the sample as the object of detection were: DOC 3.41 ppm; TN is 1.17 ppm; before injection, the sample is filtered by using a 0.45 mu m regenerated cellulose membrane, and the filtered sample water is stored in a refrigerator at 4 ℃ and injected within 3 days.

The sample to be detected was examined using the apparatus shown in FIG. 1, which provides the OCD, OND, UVD and 3DEEMD spectra of different molecular weight/hydrophobic and hydrophilic DOM components, and the above method.

When the method for synchronously characterizing the physicochemical/optical characteristics of the organic matter to be detected is performed on the instrument for synchronously characterizing the physicochemical/optical characteristics of the organic matter to be detected, all mobile phases are configured by using newly prepared ultrapure water (the resistivity is 18.2M omega. cm), so that the interference of impurities of the mobile phases on the detection result is prevented.

SEC mobile phase: phosphate buffer solution at 4mM, pH 6.8, and ionic strength adjusted to 0.5mM using sodium sulfate; the pump flow rate is 1 mL/min; the sample injection amount is 1 mL; the pump running time is 70 min; sample introduction time is 70 min; the data acquisition time is 70 min.

HIC mobile phase: phase A: phosphate buffer solution at 4mM, pH 6.8 and adjusted ionic strength to 2M with sodium sulfate; phase B: phosphate buffered solution at 4mM, pH 6.8. The elution gradient was: 0-1 min: 100-0% of phase A and 0-100% of phase B; 1-1.5 min: phase A0%, phase B100%; 1.5-2 min: 100% of phase A and 0% of phase B. The pump flow rate was 2 mL/min.

As shown in fig. 5, LC₁-SEC represents a first-dimension SEC separation; LC (liquid Crystal)₂-HIC represents a second dimension HIC separation. LC (liquid Crystal)₁SEC chromatograms decreasing in molecular weight from left to right, LC₂The HIC chromatogram is progressively more hydrophobic from top to bottom, so that the DIN component is fixed in the upper right corner and is effectively separated from the DON component. The remainder was different molecular weight/hydrophobic and hydrophilic DON content (expressed in shades of color, raw data has been normalized for ease of comparison). And (3) extracting the color data in the figure 5, and establishing a DON content quantitative matrix of DOM with different molecular weights/hydrophilicity and hydrophobicity, wherein each letter and number combination represents the content of the DOM as shown in figure 6. For example: A1-A7 show the hydrophilic-hydrophobic size arrangement (1-7) of components with molecular weight A in the region, and the other positions can be analogized in turn. Specifically, the OND quantitative matrix data is shown in table 1, the OCD quantitative matrix data is shown in table 2, the UVD quantitative matrix data is shown in table 3, the protein substance (Em ═ 340nm) quantitative matrix data in 3DEEMD is shown in table 4, and the humic substance (Em ═ 440nm) quantitative matrix data in 3DEEMD is shown in table 5.

TABLE 1 OND quantitative matrix data

	A	B	C	D	E	F	G	H	I
											1	0.03	0.03	0.00	0.00	0.07	0.00	0.72	0.69	0.55
2	1.00	0.59	0.55	0.72	0.59	0.55	0.00	0.07	0.00
										3	0.00	0.00	0.55	0.66	0.76	0.55	0.00	0.07	0.00
4	0.00	0.03	0.03	0.52	0.55	0.59	0.00	0.07	0.00
										5	0.03	0.03	0.03	0.00	0.55	0.55	0.00	0.55	0.55
6	0.45	0.52	0.55	0.00	0.48	0.48	0.52	0.59	0.59
										7	0.41	0.55	0.57	0.00	0.48	0.48	0.52	0.55	0.52

Table 2 OCD quantitative matrix data

	A	B	C	D	E	F	G	H	I
											1	0.01	0.01	0.02	0.02	0.02	0.00	0.01	0.01	0.03
2	0.73	0.59	0.56	1.00	0.60	0.57	0.00	0.08	0.00
										3	0.00	0.02	0.57	0.65	0.78	0.55	0.00	0.09	0.03
4	0.00	0.04	0.02	0.50	0.53	0.59	0.00	0.05	0.00
										5	0.04	0.04	0.01	0.01	0.56	0.54	0.00	0.15	0.18
6	0.56	0.52	0.58	0.00	0.48	0.45	0.05	0.05	0.24
										7	0.51	0.53	0.58	0.01	0.45	0.47	0.05	0.04	0.02

TABLE 3 UVD quantitative matrix data

	A	B	C	D	E	F	G	H	I
											1	0.00	0.00	0.00	0.05	0.01	0.04	0.01	0.00	0.00
2	0.03	0.15	0.52	1.00	0.56	0.53	0.00	0.10	0.03
										3	0.03	0.02	0.53	0.24	0.74	0.56	0.03	0.10	0.03
4	0.00	0.08	0.00	0.50	0.51	0.57	0.00	0.02	0.00
										5	0.03	0.07	0.06	0.52	0.59	0.56	0.00	0.16	0.03
6	0.02	0.05	0.54	0.54	0.46	0.50	0.01	0.05	0.53
										7	0.00	0.00	0.00	0.03	0.00	0.02	0.00	0.00	0.00

Quantitative matrix data for proteinaceous substances (Em 340nm) in DEEMD of Table 43

Quantitative matrix data for humus species (Em 440nm) in DEEMD of Table 53

	A	B	C	D	E	F	G	H	I
											1	0.01	0.01	0.02	0.02	0.02	0.00	0.01	0.01	0.03
2	0.02	0.08	0.50	1.00	0.53	0.50	0.00	0.10	0.03
										3	0.00	0.02	0.50	0.22	0.72	0.57	0.00	0.07	0.02
4	0.00	0.00	0.00	0.51	0.49	0.59	0.00	0.01	0.05
										5	0.04	0.02	0.06	0.54	0.58	0.60	0.00	0.16	0.08
6	0.03	0.02	0.52	0.55	0.41	0.52	0.00	0.07	0.50
										7	0.02	0.01	0.05	0.00	0.01	0.04	0.01	0.04	0.00

For the convenience of comparison, the numerical values in all the quantitative matrixes are subjected to normalization processing.

The 5 types of quantitative matrixes can provide abundant quantitative and qualitative detection information of the DOM, and comprehensively/systematically represent the physicochemical and optical characteristics of the DOM.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. An instrument for synchronously representing physicochemical/optical characteristics of organic matters to be detected is characterized by comprising a separation system (1), an online pretreatment system (2) and a detection system (3),

the separation system (1) comprises an automatic sample injector (1-3), an SEC chromatographic column (1-4), a switching valve (1-5) and an HIC chromatographic column (1-8) which are sequentially connected according to the flow path direction of a sample to be detected, wherein the automatic sample injector (1-3) is used for receiving the sample to be detected, the SEC chromatographic column (1-4) is used for sequentially separating the sample to be detected according to molecular weight, and the HIC chromatographic column (1-8) is used for separating the sample to be detected according to hydrophilic and hydrophobic properties;

the online pretreatment system (2) comprises an injection valve (2-3), an inorganic carbon remover (2-4) and an ultraviolet digester (2-5),

the detection system (3) comprises an ultraviolet detector (3-1), a three-dimensional fluorescence detector (3-2), an organic carbon detector (3-3) and an organic nitrogen detector (3-4);

according to the flow path direction of a sample to be detected, the HIC chromatographic column (1-8) is sequentially connected with an ultraviolet detector (3-1), a three-dimensional fluorescence detector (3-2), an injection valve (2-3), an inorganic carbon remover (2-4), an ultraviolet digester (2-5), an organic carbon detector (3-3) and an organic nitrogen detector (3-4).

2. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be detected according to claim 1, wherein the separation system (1) further comprises an SEC mobile phase (1-1) and an SEC infusion pump (1-2), and the SEC mobile phase (1-1) is connected with the autosampler (1-3) through the SEC infusion pump (1-2).

3. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be tested according to claim 1, wherein the separation system (1) further comprises an HIC mobile phase (1-6) and an HIC infusion pump (1-7), and the HIC mobile phase (1-6) is connected with the switching valve (1-5) through the HIC infusion pump (1-7).

4. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be tested according to claim 3, wherein the switching valve (1-5) comprises 5 interfaces and 2 quantitative rings, the 5 interfaces are respectively a first interface (1-5-1), a second interface (1-5-2), a third interface (1-5-3), a fourth interface (1-5-4), and a fifth interface (1-5-5), the 2 quantitative rings are respectively a first quantitative ring (1-5-6) and a second quantitative ring (1-5-7),

when the first quantitative ring (1-5-6) is not fully loaded, the switching valve (1-5) is in a first working state, at the time, the SEC chromatographic column (1-4), the first interface (1-5-1), the second interface (1-5-2), the first quantitative ring (1-5-6) and the fifth interface (1-5-5) are sequentially communicated, and the HIC infusion pump (1-7), the fifth interface (1-5-5), the second quantitative ring (1-5-7), the fourth interface (1-5-4), the third interface (1-5-3) and the HIC chromatographic column (1-8) are sequentially communicated.

5. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be measured according to claim 4, the switching valve is characterized in that when the first quantitative ring (1-5-6) is fully loaded, the switching valve (1-5) is in a second working state, at the time, the SEC chromatographic column (1-4), the first interface (1-5-1), the fourth interface (1-5-4), the second quantitative ring (1-5-7) and the fifth interface (1-5-5) are sequentially communicated, and the HIC infusion pump (1-7), the fifth interface (1-5-5), the first quantitative ring (1-5-6), the second interface (1-5-2), the third interface (1-5-3) and the HIC chromatographic column (1-8) are sequentially communicated.

6. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be tested according to claim 1, wherein the filler of the SEC chromatographic column (1-4) is selected from HW-50S filler of TOYOPEARL corporation.

7. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be measured according to claim 1, wherein the HIC chromatography column (1-8) is selected from a TSKgel Butyl-NPR chromatography column of TOYOPEARL corporation.

8. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be tested according to claim 1, wherein the online pretreatment system further comprises an acidifying agent (2-1) and an oxidizing agent (2-2), and the acidifying agent (2-1) and the oxidizing agent (2-2) are both connected with an injection valve (2-3).

9. The instrument for synchronously characterizing physicochemical/optical properties of organic matter to be tested according to claim 1, wherein the ultraviolet digestion device (2-5) comprises a metal shell (2-5-1), a low-pressure mercury lamp (2-5-2) and a spiral quartz tube (2-5-3), the low-pressure mercury lamp (2-5-2) and the spiral quartz tube (2-5-3) are both positioned in the metal shell (2-5-1), and the spiral quartz tube (2-5-3) is sleeved outside the low-pressure mercury lamp (2-5-2).

10. The instrument for synchronously representing physicochemical/optical characteristics of organic matters to be detected according to claim 1, wherein the ultraviolet detector (3-1), the three-dimensional fluorescence detector (3-2), the organic carbon detector (3-3) and the organic nitrogen detector (3-4) are all connected with a data acquisition computer (3-5).