Method for rapidly detecting anticoagulant raticide in water

Abstract

The invention discloses a method for rapidly detecting anticoagulant raticide in water, the anticoagulant raticide in water is detected through filtration, pH value adjustment, extraction and liquid chromatography and mass spectrometry dual separation, mass spectrometry parameters are optimized by adopting a flow injection mode, a standard substance is injected by a peristaltic pump at a flow rate of 10 [mu] L / min, a liquid phase is injected at a flow rate of 0.3 mL / min, and the mass spectrometry parameters are optimized. According to the method, a stable quasi-molecule ion peak is obtained by adjusting mass spectrum parameters, a better signal-to-noise ratio is achieved by adopting a negative ion mode, and the optimal signal-to-noise ratio is achieved by controlling the mass fraction of acetic acid in an acetonitrile-acetic acid mixed solution for elution to be 0.2%. The rapid detection method for the romaticide, the chlorfenafos, the bromadiolone and the bromafafos in the drinking water is established by matching with an ultra-high performance liquid chromatography tandem mass spectrometer, and the accuracy is high.

Description

Technical Field

[0001] This invention relates to the field of detecting rodenticides in water, and specifically to a method for rapidly detecting anticoagulant rodenticides in water. Background Technology

[0002] Anticoagulant rodenticides were invented in the 1940s. Due to their high efficiency, high toxicity, good palatability, and effectiveness, they quickly became the world's largest rodenticides, playing an indelible role in rodent control. Based on their chemical structure, anticoagulant rodenticides can be divided into two main categories: one uses 4-hydroxycoumarin as the parent compound, including first-generation anticoagulant rodenticides such as chlorpyrifos, warfarin, and bromadiolone, and second-generation anticoagulant rodenticides such as bromadiolone, brodifacoum, fludioxonil, cyproconazole, and chlorpyrifos; the other uses indanedione as the parent compound, including chlorpyrifos, bromadiolone, cyproconazole, and isochorazole. Second-generation anticoagulant rodenticides are the most widely used rodenticides internationally, currently extensively applied in agriculture, catering, and other industries, and are also among the most common causes of poisoning in clinical practice. According to data provided by the U.S. Poisoning Surveillance and Management Center, there were 16,000 cases of rodenticide poisoning in the United States in 2008 alone, a significant portion of which were accidental poisoning or intentional poisoning incidents caused by rodenticide in drinking water.

[0003] Anticoagulant rodenticides have a molecular structure similar to vitamin K, thus competing with liver cells for vitamin K, affecting the synthesis of clotting factors, prothrombin, and prothrombin, and prolonging clotting time. The decomposition product of second-generation anticoagulant rodenticides, benzylacetone, can damage capillary walls, making blood vessels brittle and increasing permeability, thus increasing the likelihood of bleeding. In humans, poisoning can cause bleeding in multiple sites, including the gums, mouth, nasal cavity, skin, urethra, and digestive tract, resulting in a high mortality rate. Anticoagulant rodenticides are extremely toxic; even very low concentrations in drinking water pose a threat to the environment and public health.

[0004] Currently, the main methods for detecting rodenticides include high-performance liquid chromatography, fluorescence chromatography, and ion chromatography. Sample pretreatment commonly uses liquid-liquid extraction, Soxhlet extraction, or solid-phase extraction, which generally consume large amounts of sample and require a long time, thus failing to meet the needs of rapid analysis. Summary of the Invention

[0005] The purpose of this invention is to provide a rapid method for detecting anticoagulant rodenticides in water, which solves the problems of current detection methods that consume large amounts of sample, require long time, and cannot meet the requirements for rapid analysis.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for rapid detection of anticoagulant rodenticides in water includes the following steps: Step S1: Filter the water sample using a filter membrane and adjust the pH to acidic to obtain a pretreated water sample; Step S2: Repeat solid-phase extraction on the pretreated water sample to obtain the extract; Step S3: After rinsing the extract with pure water, wash it with acetonitrile-acetic acid stripping solvent to obtain the stripping solution; Step S4: Add the eluent to an ultra-high performance chromatography-tandem mass spectrometry (HPLC-MS / MS) instrument for quantitative analysis by chromatography-mass spectrometry.

[0007] Furthermore, the filter membrane described in step S1 has a thickness of 0.45 μm and a pH value of 3.5.

[0008] Furthermore, the solid-phase extraction in step S2 is repeated 10 times, and the aspiration and discharge rate is 20 μL / s.

[0009] Furthermore, the mass fraction of acetic acid in the acetonitrile-acetic acid stripping solvent in step S3 is 0.2%.

[0010] Furthermore, the chromatographic conditions for the mass spectrometry quantitative analysis described in step S4 are as follows: mobile phase flow rate is 0.3 mL / min, and column temperature is 40 °C.

[0011] Furthermore, the mass spectrometry conditions in the quantitative mass spectrometry analysis described in step S4 are as follows: the ion source is a negative ion, the capillary voltage is 3.0 kV, the ion source temperature is 110 °C, the desolventizing temperature is 350 °C, the desolventizing flow rate is 600 L / h, the cone gas flow rate is 50 L / h, and the collision gas flow rate is 0.20 mL / min.

[0012] The beneficial effects of this invention are as follows: This application uses flow injection mode to optimize mass spectrometry parameters. The peristaltic pump injects the standard at a flow rate of 10 μL / min, and the liquid phase is injected at a flow rate of 0.3 mL / min. By adjusting the mass spectrometry parameters, a stable quasi-molecular ion peak is obtained. The negative ion mode has a better signal-to-noise ratio. The acetonitrile-acetic acid mixture used for elution is controlled at an acetic acid mass fraction of 0.2% for the optimal signal-to-noise ratio. This application uses MEPS as the extraction method and combines it with ultra-high performance liquid chromatography-tandem mass spectrometry to establish a rapid detection method for warfarin, bromadiolone, bromadiolone, and bromadiolone in drinking water with high accuracy. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 The chromatograms are of the four rodenticides used in this invention.

[0015] Figure 2 The recovery rates of the four rodenticides using the four solid-phase extraction columns in this invention are shown.

[0016] Figure 3 This invention illustrates the effect of the number of solid-phase extraction cycles on the recovery rate of four rodenticides.

[0017] Figure 4 This invention illustrates the effect of solid-phase extraction rate on the recovery rate of four rodenticides.

[0018] Figure 5 This invention illustrates the effect of the number of solid-phase extraction and drying cycles on the recovery rates of four rodenticides.

[0019] Figure 6 This invention illustrates the effect of the type of elution solvent on the recovery rate of four rodenticides.

[0020] Figure 7 This invention illustrates the effect of the amount of acid added to the elution solvent on the recovery rate of four rodenticides.

[0021] Figure 8 This invention illustrates the effect of the elution solvent volume on the recovery rate of four rodenticides.

[0022] Figure 9 This invention investigates the effect of pH value of pretreated water samples on the recovery rate of four rodenticides. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1-9 As shown in Example 1, this invention provides a method for rapid detection of anticoagulant rodenticides in water, specifically including the following steps: Step S1: Weigh 10 mg each of warfarin, bromadiolone, bromadiolone and bromadiolone and place them in a 10 mL volumetric flask. Dissolve and dilute with acetonitrile-methanol solution with a volume ratio of 1:1 to obtain a water sample of 100 ug / mL. Filter the water sample through a 0.45 μm filter membrane and adjust the pH value to 3.5 to obtain 10 mL of pretreated water sample. Step S2: Rinse the extraction head with 100 μL of acetonitrile and pure water, take 2 mL of pretreated water sample, and repeat solid phase extraction 10 times under the condition of aspiration and discharge rate of 20 μL / s to obtain the extract. Step S3: Rinse the extract with 300 μL of pure water, then elute with 120 μL of acetonitrile-acetic acid stripping solvent to obtain the stripping solution; Step S4: Add 10 μL of eluent to an ultra-high performance chromatography-tandem mass spectrometry (UHPLC-MS / MS) instrument. Perform chromatographic analysis at a mobile phase flow rate of 0.3 mL / min and a column temperature of 40 °C. Perform mass spectrometry analysis at a negative ion source, capillary voltage of 3.0 KV, ion source temperature of 110 °C, desolventizing temperature of 350 °C, desolventizing flow rate of 600 L / h, cone gas flow rate of 50 L / h, and collision gas flow rate of 0.20 mL / min.

[0025] The chromatographic mobile phase gradient is shown in Table 1.

[0026] Table 1 Time (min) A% (acetonitrile) B% (0.2% acetic acid) Curve initial 60 40 initial 1 90 10 6 2.8 90 10 6 2.9 60 40 1 The quality analysis parameters are shown in Table 2.

[0027] Table 2 substance Tapered hole voltage (V) Collision energy (eV) Length of stay (S) Mother ion / daughter ion Rat Killer 40 30 0.2 307.0＞161.0 Warfarin 45 30 0.2 291.5＞141.0 Bromadiolone 50 35 0.2 525.1＞250.0 Bromdioxanone 60 55 0.2 521.5＞92.9 Example 2

[0028] With the remaining steps unchanged, solid-phase extraction was performed using C8, C18, SAX, and HLB extraction columns, respectively. The recovery rates of the four rodenticides are as follows: Figure 2 As shown, the recovery rates of C8 extraction column were 48.9%-73.0%, C18 extraction column were 78.6%-91.2%, SAX extraction column were 68.7%-84.5%, and HLB extraction column were 92.8%-103%.

[0029] Example 3

[0030] With the remaining steps unchanged, the number of repetitions of solid-phase extraction was set to 5, 10, 15, 20, 25, and 30 times, and the recovery rates of the four rodenticides were recorded as follows: Figure 3 As shown, adsorption equilibrium was achieved after 10 repetitions.

[0031] Example 4

[0032] With the remaining steps unchanged, the solid-phase extraction absorption and discharge rates were sequentially set to 5 μL / s, 10 μL / s, 15 μL / s, 20 μL / s, 25 μL / s, and 30 μL / s, and the recovery rates of the four rodenticides were recorded as follows: Figure 4 As shown, the recovery rates of the four rodenticides were high at an absorption and emission rate of 20 μL / s.

[0033] Example 5

[0034] With the remaining steps unchanged, air extraction was used as a drying adsorption method to dry the solid-phase extract. The number of extractions was 0, 5, 10, 15, and 20, and the recovery rates of the four rodenticides were recorded as follows: Figure 5 As shown, this indicates that drying is not necessary.

[0035] Example 6

[0036] With the remaining steps unchanged, the eluent was successively replaced with methanol (MeOH), acetonitrile (ACN), acetone (ATN), ethyl acetate (EtOAc), dichloromethane (DCM), and methyl tert-butyl ether (MTBE), and the recovery rates of the four rodenticides were recorded as follows: Figure 6 As shown, acetonitrile exhibits the best elution efficiency, with recoveries exceeding 75% for all four rodenticides.

[0037] Example 7

[0038] With the remaining steps unchanged, the eluent was changed to methanol, acetonitrile, acetonitrile (containing 0.1% formic acid), acetonitrile (containing 0.1% acetic acid), acetonitrile (containing 0.2% acetic acid), and acetonitrile (containing 0.3% acetic acid). The recovery rates of the four rodenticides were recorded as follows: Figure 7 As shown, acetonitrile containing 0.2% acetic acid achieved the best elution effect for the four rodenticides.

[0039] Example 8

[0040] With the remaining steps unchanged, the amount of elution solvent was set to 50 μL, 70 μL, 100 μL, 120 μL, and 150 μL, respectively, and the recovery rates of the four rodenticides were recorded as follows: Figure 8 As shown, 120 µL of acetonitrile containing 0.2% acetic acid is the optimal elution volume, which is sufficient for eluting four rodenticides.

[0041] Example 9

[0042] With the remaining steps unchanged, the pH values ​​of the pretreated water samples were adjusted to 2, 3, 3.5, 4, and 5, respectively, and the recovery rates of the four rodenticides were recorded as follows: Figure 9 As shown, a pH of 3.5 resulted in the best elution effect for the four rodenticides.

[0043] In summary, the four rodenticide compounds exhibited good linearity in liquid chromatography-tandem mass spectrometry within the concentration range of 5-500 μg / L, with correlation coefficients (R²) ranging from 0.9968 to 0.9991.

[0044] The operation method in Example 1 resulted in the detection concentrations of four samples—warfarin, bromadiolone, bromadiolone, and bromadiolone—being 0.04 μg / L, 0.01 μg / L, 0.10 μg / L, and 0.05 μg / L, respectively, which meets the needs of actual environmental monitoring.

[0045] Precision experiments were conducted on spiked water samples with concentrations ranging from 1.0 to 50.0 μg / L, and the results are shown in Table 3.

[0046] Table 3 substance Sub-deviation (%) Daily deviation (%) Spike recovery rate (%) Rat Killer 5.9 5.4 93.9-104 Warfarin 4.1 7.9 89.9-110 Bromadiolone 7.3 13.2 84.5-95.7 Bromdioxanone 6.3 14.4 87.1-102 The average relative standard deviation (RSD) of the method was 4.1%-7.3% for six tests within the same day and 5.4%-14.4% for six days, which is far below the generally required level of less than 20% for water analysis. Following the analytical conditions and procedures defined in this method, water samples with different concentrations of four rodenticides (0.5 μg / L, 1.0 μg / L, and 10.0 μg / L) were selected for spiking experiments, and the recovery rates ranged from 84.5% to 110%.

[0047] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for rapid detection of anticoagulant rodenticides in water, characterized in that: Specifically, the steps include the following: Step S1: Filter the water sample using a filter membrane and adjust the pH to acidic to obtain a pretreated water sample; Step S2: Repeat solid-phase extraction on the pretreated water sample to obtain the extract; Step S3: After rinsing the extract with pure water, wash it with acetonitrile-acetic acid stripping solvent to obtain the stripping solution; Step S4: Add the eluent to an ultra-high performance chromatography-tandem mass spectrometry (HPLC-MS / MS) instrument for quantitative analysis by chromatography-mass spectrometry.

2. The method for rapid detection of anticoagulant rodenticides in water according to claim 1, characterized in that: The filter membrane described in step S1 has a thickness of 0.45 μm and a pH value of 3.

5.

3. The method for rapid detection of anticoagulant rodenticides in water according to claim 1, characterized in that: The solid-phase extraction in step S2 is repeated 10 times, and the aspiration and discharge rate is 20 μL / s.

4. The method for rapid detection of anticoagulant rodenticides in water according to claim 1, characterized in that: The mass fraction of acetic acid in the acetonitrile-acetic acid stripping solvent described in step S3 is 0.2%.

5. The method for rapid detection of anticoagulant rodenticides in water according to claim 1, characterized in that: The chromatographic conditions for the mass spectrometry quantitative analysis described in step S4 are as follows: mobile phase flow rate is 0.3 mL / min, and column temperature is 40 °C.

6. The method for rapid detection of anticoagulant rodenticides in water according to claim 1, characterized in that: The mass spectrometry conditions for the quantitative analysis described in step S4 are as follows: the ion source is a negative ion source, the capillary voltage is 3.0 kV, the ion source temperature is 110 °C, the desolventizing temperature is 350 °C, the desolventizing flow rate is 600 L / h, the cone gas flow rate is 50 L / h, and the collision gas flow rate is 0.20 mL / min.

Images