1. A method for detecting disinfection byproducts by processing environmental samples through vortex-assisted dispersion liquid-liquid microextraction is characterized by comprising the following steps: taking an environmental water sample, quickly injecting a dispersing agent into a polytetrafluoroethylene centrifugal tube with a plug tip bottom, then injecting an extracting agent, standing after vortex oscillation to enable a sample solution, the dispersing agent and the extracting agent to form an emulsion, finally performing centrifugal separation, taking out the upper-layer extracting agent, placing the upper-layer extracting agent into a gas chromatography sampling bottle, and analyzing related disinfection byproducts by using a gas chromatography mass spectrometer.

2. The method for processing environmental samples to detect disinfection byproducts of vortex-assisted dispersion liquid microextraction according to claim 1, wherein the environmental water sample is municipal water supply or municipal sewage.

3. The method for processing environmental samples for detection of disinfection byproducts by vortex-assisted dispersion liquid microextraction according to claim 1, wherein the volume of the environmental water sample is 10-30 mL.

4. The method for detecting disinfection byproducts in a vortex-assisted dispersion liquid microextraction process environmental sample of claim 1 wherein the volume of said dispersant is 30-100 μ L.

5. The method for detecting disinfection byproducts by vortex-assisted dispersion liquid microextraction processing of environmental samples according to claim 1, wherein the dispersant is acetone or acetonitrile.

6. The method as claimed in claim 1, wherein the volume of the extraction agent is 200 μ L and 100-.

7. The method of claim 1, wherein said extraction reagent is selected from the group consisting of methyl tert-butyl ether and methylene chloride.

8. The method as claimed in claim 1, wherein the rotational speed of vortex oscillation is 2000-4000 r/min; and standing for 2-4min after vortex oscillation.

9. The method as claimed in claim 1, wherein the rotational speed of the centrifugal separation is 3000-; the centrifugal separation time is 2-4 min.

10. The method as claimed in claim 1, wherein the volume of the extraction solvent at the upper layer is 100-200 μ L.

Background

The water quality safety of drinking water is a significant civil problem for thousands of households. The implementation of drinking water disinfection technology effectively inhibits the spread of water-mediated infectious diseases such as cholera and typhoid, and protects tens of thousands of people from the threat of the diseases. The common disinfectant has strong oxidizing property, and can oxidize natural organic matters, inorganic matters (Br-and I-) and artificial pollution in water body to generate Disinfection Byproducts (DBPs) while killing pathogenic microorganisms. Most DBPs have cytotoxicity, neurotoxicity, mutagenicity, genotoxicity, teratogenicity, and carcinogenicity. Accurate quantification of DBPs has been a focus of attention in the municipal and environmental fields. The existing method for enriching the disinfection byproducts is liquid-liquid extraction (LLE), the LLE commonly used in DBPs detection utilizes the different solubilities of DBPs in water and an organic solvent, and redistributes the DBPs in the process of oscillation and mixing, so that a target substance is transferred from the water to the organic solvent, and the aim of separation, enrichment or purification is fulfilled. The method is widely applied due to simple operation. However, the LLE enrichment factor is limited, and a large volume of water sample and organic solvent extractant are used to increase the enrichment factor, so that the sample treatment cost is increased and the pollution caused by the use of a large amount of solvent is increased.

Disclosure of Invention

The invention aims to provide energy. A method for detecting disinfection byproducts by processing an environmental sample through vortex-assisted dispersion liquid microextraction.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for detecting disinfection byproducts by processing environmental samples through vortex-assisted dispersion liquid-liquid microextraction comprises the following steps: taking an environmental water sample, quickly injecting a dispersing agent into a polytetrafluoroethylene centrifugal tube with a plug tip bottom, then injecting an extracting agent, standing after vortex oscillation to enable a sample solution, the dispersing agent and the extracting agent to form an emulsion, finally performing centrifugal separation, taking out the upper-layer extracting agent, placing the upper-layer extracting agent into a gas chromatography sampling bottle, and analyzing related disinfection byproducts by using a gas chromatography mass spectrometer.

Preferably, the environmental water sample is municipal water supply or municipal sewage.

Preferably, the volume of the environmental water sample is 10-30 mL.

Preferably, the volume of the dispersant is 30-100. mu.L.

Preferably, the dispersant is acetone or acetonitrile.

Preferably, the volume of the extractant is 100-.

Preferably, the kind of the extracting agent adopts methyl tert-butyl ether or dichloromethane.

Preferably, the rotation speed of the vortex oscillation is 2000-4000 r/min; and standing for 2-4min after vortex oscillation.

Preferably, the rotation speed of the centrifugal separation is 3000-4000 r/min; the centrifugal separation time is 2-4 min.

Preferably, the volume of the extraction upper layer extractant is 100-200. mu.L.

The invention has the beneficial effects that:

the invention provides a method for detecting disinfection byproducts by processing environmental samples through liquid-liquid microextraction of dispersion liquid, which is different from the existing method for detecting DBPs (DBPs) by preprocessing LLE samples.

Secondly, compared with the traditional LLE sample pretreatment method, the invention improves the enrichment multiple of the sample by more than 20 times, saves the consumption of a water sample and an organic extractant while ensuring the enrichment multiple, reduces the cost, reduces the adverse effect and damage to the ecological environment and is more environment-friendly.

Thirdly, the whole experiment process is simple to operate, rapid and sensitive, and the whole pretreatment method has high recovery rate and good reproducibility, which indicates that the method is suitable for detecting the disinfection byproducts in the environmental sample.

The method is simple to operate, rapid and sensitive, good in method reproducibility and low in solvent consumption, is an environment-friendly pretreatment method, and can be widely used for detecting the disinfection byproducts of the environmental samples.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

The invention discloses a method for detecting disinfection byproducts by processing an environmental sample through vortex-assisted dispersion liquid microextraction, which comprises the following steps:

taking an environmental water sample, quickly injecting a dispersing agent into a polytetrafluoroethylene centrifugal tube with a plug tip bottom, then injecting an extracting agent, standing after vortex oscillation to enable a sample solution, the dispersing agent and the extracting agent to form an emulsion, finally performing centrifugal separation, taking out the upper-layer extracting agent, placing the upper-layer extracting agent into a gas chromatography sampling bottle, and analyzing related disinfection byproducts by using a gas chromatography mass spectrometer. Analysis of the disinfection byproducts includes one or more of trihalomethanes, haloacetonitrile, haloacetaldehyde, halonitromethane, haloketones.

Example 1

Detection of dibromomonochloromethane in tap water

1.1 Water sample treatment Process

(1) Traditional liquid-liquid extraction pretreatment: accurately measuring 20mL of tap water sample into a 25mL glass bottle with a polytetrafluoroethylene bottle cap, adding 4mL of methyl tert-butyl ether extractant, performing vortex oscillation at a rotation speed of 2500r/min for 5min, standing for 2min, taking 1mL of supernatant into a gas chromatography sampling bottle, and analyzing dibromomonochloromethane by using a gas chromatography mass spectrometer.

(2) Carrying out vortex-assisted dispersion liquid-liquid microextraction pretreatment: accurately weighing 20mL of tap water sample into a 25mL polytetrafluoroethylene centrifuge tube with a plugged tip bottom, quickly injecting 100 μ L of methanol as a dispersing agent, then injecting 200 μ L of dichloromethane as an extracting agent, performing vortex oscillation at a rotating speed of 2500r/min for 3min, standing for 2min to enable the sample solution, the dispersing agent and the extracting agent to form an emulsion, finally performing centrifugal separation at a rotating speed of 3500r/min for 3min, taking out the lower-layer extracting agent, placing the lower-layer extracting agent into a gas chromatography sample inlet bottle, and analyzing dibromomonochloromethane by using a gas chromatography mass spectrometer.

1.2 instrumental detection of parameters

The carrier gas is high-purity helium, the flow control mode of the carrier gas is pressure control, the sample injection mode is non-split-flow sample injection, the temperature of a sample injection port is 220 ℃, the temperature of a mass spectrum detector is 260 ℃, the ion source is an electron bombardment ion source, the electron energy is 70eV, and the detection mode is a selective ion detection mode. The initial temperature is 50 ℃, and the temperature is kept for 5 min; then raising the temperature to 180 ℃ at the speed of 20 ℃/min, and keeping the temperature for 2 min; the temperature is increased to 240 ℃ at a speed of 35 ℃/min and kept for 3 min. The peak-out time of dibromomonochloromethane is 4.3 min.

1.3 test results

In the traditional liquid-liquid extraction pretreatment mode, the detection limit of the method for preparing the dibromo-chloromethane is 0.7 mu g/L, the recovery rate of the dibromo-chloromethane is 67 percent, and the relative standard deviation is 10 percent.

The invention adopts a vortex-assisted dispersion liquid-liquid microextraction pretreatment mode, the detection limit of the method for dibromo-chloromethane is 0.05 mu g/L, the recovery rate of the dibromo-chloromethane is 92%, and the relative standard deviation is 4%.

In conclusion, compared with the traditional liquid-liquid extraction pretreatment, the detection limit of the target dibromomonochloromethane is reduced by 14 times, and the recovery rate is improved by 25%.

Example 2

Detection of dichloroacetonitrile in municipal wastewater

1.1 Water sample treatment Process

(1) Traditional liquid-liquid extraction pretreatment: accurately measuring 10mL of tap water sample into a 20mL glass bottle with a polytetrafluoroethylene bottle cap, adding 2mL of methyl tert-butyl ether extractant, performing vortex oscillation at the rotation speed of 2700r/min for 5min, standing for 2min, taking 1mL of supernatant into a gas chromatography sampling bottle, and analyzing dichloroacetonitrile by using a gas chromatography mass spectrometer.

(2) Carrying out vortex-assisted dispersion liquid-liquid microextraction pretreatment: accurately weighing 10mL of tap water sample into a 15mL of polytetrafluoroethylene centrifuge tube with a plug tip, quickly injecting 50 μ L of methanol as a dispersing agent, then injecting 150 μ L of dichloromethane as an extracting agent, performing vortex oscillation at the rotating speed of 2700r/min for 3min, standing for 2min to enable the sample solution, the dispersing agent and the extracting agent to form an emulsion, finally performing centrifugal separation at the rotating speed of 3200r/min for 3min, taking out the lower-layer extracting agent, placing the lower-layer extracting agent into a gas chromatography sample inlet bottle, and analyzing dichloroacetonitrile by using a gas chromatography mass spectrometer.

1.2 instrumental detection of parameters

The carrier gas is high-purity helium, the flow control mode of the carrier gas is pressure control, the sample injection mode is non-split-flow sample injection, the temperature of a sample injection port is 220 ℃, the temperature of a mass spectrum detector is 260 ℃, the ion source is an electron bombardment ion source, the electron energy is 70eV, and the detection mode is a selective ion detection mode. The initial temperature is 35 ℃, and the temperature is kept for 2 min; then raising the temperature to 120 ℃ at the speed of 10 ℃/min, and keeping the temperature for 2 min; the temperature is raised to 260 ℃ at a speed of 35 ℃/min and kept for 3 min. The peak-out time of dibromomonochloromethane is 5.0 min.

1.3 test results

In the traditional liquid-liquid extraction pretreatment mode, the detection limit of the dichloroacetonitrile method is 0.8 mu g/L, the recovery rate of the dichloroacetonitrile is 72 percent, and the relative standard deviation is 9 percent.

The invention adopts a vortex auxiliary dispersion liquid-liquid microextraction pretreatment mode, the detection limit of the method of dichloroacetonitrile is 0.08 mu g/L, the recovery rate of dibromo-chloromethane is 90%, and the relative standard deviation is 5%.

In conclusion, compared with the traditional liquid-liquid extraction pretreatment, the detection limit of the target dibromomonochloromethane is reduced by 10 times, and the recovery rate is improved by 18 percent.

The method is simple to operate, rapid and sensitive, good in method reproducibility and low in solvent consumption, is an environment-friendly pretreatment method, and can be widely used for detecting the disinfection byproducts of the environmental samples.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.