CN109633071B

CN109633071B - Method for detecting Saisentong copper in water by using UPLC-MS/MS method

Info

Publication number: CN109633071B
Application number: CN201910145853.7A
Authority: CN
Inventors: 黄玉贵; 林绍霞; 何钰; 陈迎丽; 何伟; 王睿
Original assignee: GUIZHOU ACADEMY OF TESTING AND ANALYSIS; Guizhou Jian'ande Technology Co ltd
Current assignee: GUIZHOU ACADEMY OF TESTING AND ANALYSIS; Guizhou Jian'ande Technology Co ltd
Priority date: 2019-02-27
Filing date: 2019-02-27
Publication date: 2021-05-07
Anticipated expiration: 2039-02-27
Also published as: CN109633071A

Abstract

The invention relates to a method for detecting Saisentong copper in water by using a UPLC-MS/MS method, belonging to the technical field of pesticide environment detection. EDTA-Na used in the method₂And L-cysteine hydrochloride, detecting by UPLC-MS/MS, and quantifying by using Agilent Hilic Plus RRHD (2.1 × 50mm, 1.8 μm) hydrophilic chromatographic column and MSD detector and external standard method. The precision RSD% of the method is 1.14%, a linear equation Y is 48.1324X +0431, and a correlation coefficient R²0.9997, average recovery rate of 86.89%, LOD of 0.427 μ g/L, LOQ of 1.422 μ g/L, simple operation, rapid analysis, accurate result, good separation effect, and high sensitivity.

Description

Method for detecting Saisentong copper in water by using UPLC-MS/MS method

Technical Field

The invention relates to the technical field of environmental detection, in particular to a method for detecting Saisentong in water by using a UPLC-MS/MS method.

Background

Thiessen copper is thiazole organic copper bactericide, and is mainly used for preventing and treating rice bacterial leaf blight, bacterial leaf streak, cabbage soft rot and tomato bacterial wilt. The pesticide has the advantages of high efficiency, broad spectrum, low toxicity, safety, environmental protection, no public nuisance, special effect on bacterial diseases, high efficiency on fungal diseases, stability under acidic conditions, capability of being mixed with other pesticides, and is one of the major recommended pesticide varieties in national center of agriculture of the Ministry of agriculture.

The detection and analysis method of Saisentong only reports high performance liquid chromatography at present, the method not only needs derivatization, but also needs repeated extraction, the operation is complex, the derivatization conversion rate is not high, the stability of a derivatization product is poor, the detection limit is too high, the sensitivity is low, the repeatability is poor, and the detection of pesticide residues in modern agriculture and low-content pesticides in water environment can not be met. However, the method for detecting the Saisen copper by LC-MS/MS is not reported at home and abroad, so that a special and effective detection method is necessarily explored to be applied to the analysis and detection of the Saisen copper.

Thiessen copper residue analysis method, GuoZhiqiang, Wuli, Wangqiang, Li Zheng, Zhaohua, Thiessen copper residue analysis method [ J ] pesticide, 2009,48(07):509 one-step 510 Thiessen copper residue analysis method, which comprises the steps of adopting sodium thiosulfate to hydrolyze, finding out the conversion relation between the Thiessen copper and AMT, and establishing the high performance liquid chromatography determination method of the Thiessen copper residue in water. The mobile phase was acetonitrile-0.01% aqueous acetic acid (30: 70 by volume). The experimental result shows that the conversion coefficient of the Thiessen copper into the AMT in the water is 0.4556, the average recovery rate of the method is (90.7 +/-2.6)%, and the relative standard deviation is less than 3.25%. The method has the advantages of low average recovery rate, large relative deviation, relatively complex experimental process and poor stability of detection results.

CN 103592404B-a method for detecting the residual quantity of organic copper pesticides in fruits and vegetables, discloses a method for detecting the residual quantity of organic copper pesticides in fruits and vegetables, adopts dispersive solid phase extraction-ultra high performance liquid chromatography-tandem mass spectrometry to detect, and specifically comprises the following steps: (1) preparing a standard solution; (2) adding a complex breaking agent into a sample to break the complex, then adding methanol, performing vortex oscillation and ultrasonic extraction; (3) purifying; (4) detecting by an instrument: by the series of concentrates in step (1)Injecting a standard working solution, detecting UPLC-MS/MS, and carrying out UPLC-MS/MS detection on the purified sample collected in the step (3); (5) establishing a standard curve; (6) and analyzing the result, and calculating the content of the organic copper pesticide in the sample. The complex breaking agent comprises sodium sulfide (Na)₂S), ferrous sulfate (FeSO)₄) Sodium hypochlorite (NaC)_lO) And a Fenton reagent, wherein some reagents are toxic or may generate toxicity when reacting with other reagents, and a solid reagent is directly added to break the complex, so that the method for detecting the Saisen copper in the water provided by the invention has poor complex breaking effect. The minimum detectable amount was 1.2X 10^-11g, the lowest detection concentration is 0.01mg/kg and is 0.427 mu g/L higher than the detection limit of the invention;

the high performance liquid chromatography method for determining the residual quantity of the Thiessen copper in the tobacco, namely Lizhining and the Fine chemical research and development center of Guizhou university discloses an analysis method for determining the residual quantity of the Thiessen copper in the tobacco by high performance liquid chromatography (HPLC-DAD). A tobacco sample is subjected to derivation and extraction by a sodium thiosulfate solution, centrifugation, trichloroethylene purification, ethyl acetate extraction and high performance liquid chromatography detection. The average recovery rate of the method is 79.55-98.16%, the relative standard deviation is 0.94-7.55%, the lowest detection limit of the Thisen copper is 1.8ng, the lowest detection limit of the Thisen copper in a tobacco leaf sample is 0.5mg/kg, and the method is suitable for accurately detecting the Thisen copper residual quantity in a tobacco matrix, but for trace Thisen copper in water, the method cannot meet the detection requirement.

CN 106198508B-a method for high-sensitivity rapid detection of pesticides containing heavy metals, which discloses contacting a sensor with pesticides, enabling an indicator on the sensor to generate a color reaction through the chelation between the indicator and heavy metals in the pesticides containing heavy metals, enriching quantitative pesticides through the sensor to improve the color change intensity of the indicator, then collecting images before and after the indicator reaction by using imaging equipment, and extracting color change values of three channels of red, green and blue (RGB); and then calculating by using a formula to obtain a color change value ED before and after the sensor reacts with the pesticide, wherein the method is a supplement method of the existing pesticide residue quick detection method, the detection limit is in the level of mg/kg for detecting the Thisen copper residue, and the aim of detecting the Thisen copper residue in water cannot be fulfilled when the concentration of the Thisen copper residue is lower.

Disclosure of Invention

The invention aims to overcome the defects of high detection limit, low sensitivity, poor repeatability and the like in the prior art and provides a detection method for detecting the Saisentong copper in water by using a UPLC-MS/MS method. The method comprises the following steps: 1) preparing an EDTA mixed solution: weighing 0.5-2 g of EDTA-Na₂Placing 1-5 g L-cysteine into a 1000mL beaker, adding 900mL of water, adjusting the pH value to 10-14 by using 1-3 mol/L NaOH, transferring into a 1000mL volumetric flask, and fixing the volume to a scale to obtain an EDTA mixed solution; 2) preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 2-10 min, taking 2.0mL of the sample in a 2000mL beaker, diluting the sample to 2000mL of the scale with the aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, treating the Thisen copper aqueous solution to be detected with EDTA mixed solution 1: 1-1: 3 to obtain a derivatized Thisen copper solution, and performing UPLC-MS/MS detection; 3) preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, fixing the volume to scale to obtain standard sample stock solution with the concentration of Saisen copper of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series gradient of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS measurement; 4) measurement and calculation of results: setting instrument parameters, performing UPLC-MS/MS determination on the reference solution and the test solution after the instrument is stabilized, recording a chromatogram, and calculating according to an external standard method by taking the content of the Thiessen copper derivative as the content of the Thiessen copper. Preferably, the method comprises the steps of: 1) preparing an EDTA mixed solution: weighing 1-1.5 g of EDTA-Na₂Adding 900mL of water into a 1000mL beaker containing 2-4 g L-cysteine, adjusting the pH value to 11-13 by using 1.5-2.5 mol/L NaOH, transferring the beaker into a 1000mL volumetric flask, and fixing the volume to a scale to obtain an EDTA mixed solution; 2) preparation of a test solution: weighing 0.3232g of 30 percent Chunlei Thiessen copper suspending agent sample in a 100mL volumetric flask, adding aerated water to dilute to a scale mark,performing ultrasonic treatment for 3-8 min, putting 2.0mL of the aqueous solution into a 2000mL beaker, diluting the aqueous solution to 2000mL of scales by using aerated water to obtain 808 mug/L of the aqueous solution of the Thiessen copper to be detected, treating the aqueous solution of the Thiessen copper to be detected by using EDTA mixed solution in a ratio of 1: 1-1: 2 to obtain derivatized Thiessen copper solution, and detecting by using UPLC-MS/MS; 3) preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, fixing the volume to scale to obtain standard sample stock solution with the concentration of Saisen copper of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series gradient of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS measurement; 4) measurement and calculation of results: setting instrument parameters, performing UPLC-MS/MS determination on the reference solution and the test solution after the instrument is stabilized, recording a chromatogram, and calculating according to an external standard method by taking the content of the Thiessen copper derivative as the content of the Thiessen copper.

Further preferably, the method comprises the steps of: 1) preparing an EDTA mixed solution: 1.21g of EDTA-Na was weighed₂Adding 900mL of water into a 1000mL beaker containing 3.72g L-cysteine, adjusting the pH value to 12 by using 2mol/LNaOH, transferring the beaker into a 1000mL volumetric flask, and fixing the volume to the scale to obtain an EDTA mixed solution; 2) preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aerated water to dilute the sample to a scale, carrying out ultrasonic treatment for 5min, taking 2.0mL of the sample in a 2000mL beaker, diluting the sample to the 2000mL scale with the aerated water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, treating the Thisen copper aqueous solution to be detected with EDTA mixed solution 1:1 to obtain a derivatized Thisen copper solution, and detecting the Thisen copper solution by UPLC-MS/MS; 3) preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, fixing the volume to scale to obtain standard sample stock solution with the concentration of Saisen copper of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series gradient of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS measurement; 4) measurement and calculation of results: setting instrument parameters, dissolving reference substance solution and test substance after instrument is stabilizedAnd (4) carrying out UPLC-MS/MS measurement on the liquid, recording a chromatogram, taking the content of the Thiessen copper derivative as the content of the Thiessen copper, and calculating according to an external standard method.

The EDTA mixed solution treatment sample solution and standard sample solution comprises the following steps: (1) the step of processing the sample solution by the EDTA mixed solution is as follows: diluting a sample to be detected with a Saisentong copper aqueous solution by using an EDTA (ethylene diamine tetraacetic acid) mixed solution according to a volume ratio of 1:3, carrying out vortex mixing for 5-20 min, carrying out ultrasonic treatment for 5-20 min after full reaction, and filtering by using a 0.45-micrometer filter membrane to obtain the Saisentong copper aqueous solution; (2) the method for treating the standard sample solution by the EDTA mixed solution comprises the following steps: weighing a Saisen copper standard sample, dissolving and diluting the Saisen copper standard sample by using EDTA mixed solution, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min, fixing the volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution by using the EDTA mixed solution to prepare standard working solution with the series gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination; the transformation process of the Saisentong copper in the EDTA mixed solution is as follows:

preferably, the preparation steps of the EDTA mixed solution treatment sample solution and the standard sample solution are as follows: (1) the step of processing the sample solution by the EDTA mixed solution is as follows: diluting a sample to be detected with a Saisentong copper aqueous solution by using an EDTA (ethylene diamine tetraacetic acid) mixed solution according to a volume ratio of 1:2, carrying out vortex mixing for 5-10 min, carrying out ultrasonic treatment for 5-10 min after full reaction, and filtering by using a 0.45-micrometer filter membrane to obtain the Saisentong copper aqueous solution; (2) the method for treating the standard sample solution by the EDTA mixed solution comprises the following steps: weighing a Saisen copper standard sample, dissolving and diluting the Saisen copper standard sample by using EDTA mixed solution, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min, fixing the volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution by using the EDTA mixed solution to prepare standard working solution with the series gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination; the transformation process of the Saisentong copper in the EDTA mixed solution is as follows:

more preferably, the preparation steps of the EDTA mixed solution treatment sample solution and the standard sample solution are as follows: (1) the step of processing the sample solution by the EDTA mixed solution is as follows: diluting a sample to be detected with a Saisentong copper aqueous solution by using an EDTA (ethylene diamine tetraacetic acid) mixed solution according to a volume ratio of 1:1, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min after full reaction, and filtering by using a 0.45-micrometer filter membrane to obtain the Saisentong copper aqueous solution; (2) the method for treating the standard sample solution by the EDTA mixed solution comprises the following steps: weighing a Saisen copper standard sample, dissolving and diluting the Saisen copper standard sample by using EDTA mixed solution, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min, fixing the volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution by using the EDTA mixed solution to prepare standard working solution with the series gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination; the transformation process of the Saisentong copper in the EDTA mixed solution is as follows:

the UPLC-MS/MS determination is carried out under the HPLC operating conditions that:

1) sample introduction volume: 3.0 mu L;

2) flow rate: 0.5 mL/min;

3) column temperature: 40 ℃;

4) elution solvent and procedure:

eluting solvent: mobile phase A: acetonitrile, mobile phase B: 0.1% formic acid water; the elution procedure was:

time (minutes)	Mobile phase A (%)	Flow ofPhase B (%)
			0～2.5min	82％～90％	18％～10％
2.5～3.1min	90％～82％	10％～18％
			3.1～7.0min	82％	18％

UPLC-MS/MS measurement, MSD operation conditions are:

1) and (3) monitoring mode: MRM;

2) a negative ion mode;

3) ion source parameters: drying gas: n is a radical of₂(ii) a Temperature of the drying gas: 350 ℃; flow rate of drying gas: 7L/min; sheath gas: n is a radical of₂(ii) a Temperature of sheath gas: 100 ℃; flow rate of sheath gas: 9L/min; atomizer pressure: 55 psi; nozzle voltage: 500V; capillary voltage: 4500V, EMV gain (-): 500V.

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

And (3) qualitative identification: for the parent ion and the ion pair of the pesticide, if the ion chromatographic retention time is consistent with that of the standard sample working solution (the variation range is within +/-2.5 percent); and when the ion abundance Ratio (Ratio) of the target compound in the sample is not more than 20%, judging that the detected mass spectrum signal is the pesticide, and if the two conditions cannot be met simultaneously, judging that the pesticide is not contained.

The method has the detection limit LOD of 0.427 mu g/L and the LOQ of 1.422 mu g/L for the Saisen copper. The invention has the following advantages:

1. the detection methodology of the invention verifies that the sample injection concentration of the Saisentong copper is in good linear relation in the range of 9.66 mu g/L-483.00 mu g/L, the linear equation is that y is 12.67x-1.45, R²The relative standard deviation of 0.9997 is 1.14, the average recovery rate is 86.89%, the LOD is 0.427 mu g/L, and the LOQ is 1.422 mu g/L, and the method has the advantages of simple operation, quick analysis, accurate result, good separation effect and high sensitivity.

2. According to the method for detecting the Saisentong copper in the water, provided by the invention, EDTA mixed solution is adopted for derivatization treatment, so that substances which are difficult to analyze are converted into substances which are similar to the chemical structures of the substances but easy to analyze, and the quantification and the separation are facilitated.

3. The method overcomes the high detection limit of the traditional methods such as gas chromatography, high performance liquid chromatography and the like, the sample is complex to process, the detection limit of the method can reach 0.427 mu g/L, the quantification limit reaches 1.422 mu g/L, the sensitivity is high, the content of the Saisentong in the water can be well detected, and the method has important significance for aquatic animal protection and water resource protection through reference basis for water quality evaluation and environmental protection.

Description of the drawings:

FIG. 1: qualitative and quantitative ion and ion abundance ratio map of Saisen copper

FIG. 2: saisen copper standard curve diagram

FIG. 3: saisentong standard chromatogram

FIG. 4: saisen copper sample chromatogram

The specific implementation mode is as follows:

the invention is further described with reference to the drawings and the following detailed description, which are not intended to limit the invention in any way. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated. Unless otherwise specified, all the raw materials and equipment used in this example were those conventionally available in the art.

Instruments and reagents involved in the following examples include, but are not limited to: an ultrahigh-pressure high performance liquid chromatography-mass spectrometer (Agilent 1290-; a chromatographic column: agilent Hilic Plus RRHD (2.1X 50mm, 1.8 μm);

reagent: acetonitrile: chromatographically pure, Merck corporation, (ii) C

Reag.Ph Eur，Lot：JA069430)；

Formic acid: chromatographic purity, Shanghai' an spectral science instruments, Inc. (CNW Technologies, Lot: K3560090);

disodium ethylene diamine tetraacetate: analytical purity, chemical reagents of national drug group limited, Lot No: f20110105;

l-cysteine hydrochloride (anhydrous): national pharmaceutical group chemical reagents ltd, Lot No: 20160301;

saisen copper standard: the known mass fraction, omega is 92.0%, provided by Zhejiang Oriental chemical Co., Ltd;

30% sample of Chunlei Saisen copper suspending agent (wherein the mass molecule number of the Saisen copper is 25%, the mass fraction of the kasugamycin is 5%), Zhejiang Dongfeng chemical Co., Ltd.

Ultrapure water: resistivity, 18.2M Ω cm;

aeration water: the material is prepared in a laboratory and is obtained by carrying out aeration treatment on ultrapure water.

Example 1

Preparing an EDTA mixed solution: 0.5g of EDTA-Na was weighed₂Placing 1g L-cysteine into a 1000mL beaker, adding 900mL of water, adjusting the pH value to 10 by using 1mol/L NaOH, transferring the solution into a 1000mL volumetric flask, and fixing the volume to the scale to obtain an EDTA mixed solution;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 2min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:1, performing vortex mixing for 5min, performing ultrasonic treatment for 5min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min after full reaction, dissolving and diluting the sample with the EDTA mixed solution to scale, filtering the sample with a 0.45um filter membrane, carrying out constant volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series of gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination;

measurement and calculation of results: setting instrument parameters, carrying out UPLC-MS/M determination on the reference solution and the test solution after the instrument is stable, and recording the peak area of the chromatogram; and (3) drawing a standard curve by taking the concentration of the Thiessen copper derivative as an abscissa and the peak area of the Thiessen copper derivative as an ordinate, substituting the peak area of the Thiessen copper derivative measured in the test sample into the standard curve to obtain the content of the Thiessen copper derivative in the test sample solution, and calculating by taking the content of the Thiessen copper derivative as the content of the Thiessen copper.

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

the elution procedure was: mobile phase A: acetonitrile, mobile phase B: 0.1% formic acid water

Time (minutes)	Mobile phase A (%)	Mobile phase B (%)
			0～2.5min	82％～90％	18％～10％
2.5～3.1min	90％～82％	10％～18％
			3.1～7.0min	82％	18％

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

ion source parameters: drying gas: n is a radical of₂(ii) a Temperature of the drying gas: 350 ℃; flow rate of drying gas: 7L/min; sheath gas: n is a radical of₂(ii) a Temperature of sheath gas: 100 ℃; flow rate of sheath gas: 9L/min; atomizer pressure: 55 psi; nozzle voltage: 500V; capillary voltage: 4500V, EMV gain (-): 500V.

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 2

Preparing an EDTA mixed solution: weighing 1g of EDTA-Na₂Placing 2g L-cysteine into a 1000mL beaker, adding 900mL of water, adjusting the pH value to 11 by using 2mol/LNaOH, transferring the solution into a 1000mL volumetric flask, and fixing the volume to the scale to obtain an EDTA mixed solution;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 3min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:1.5, performing vortex mixing for 6min, performing full reaction, performing ultrasonic treatment for 6min, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, carrying out vortex mixing for 6min, carrying out ultrasonic treatment for 6min after full reaction, dissolving and diluting the sample with the EDTA mixed solution to scale, filtering the sample with a 0.45um filter membrane, carrying out constant volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series of gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 3

Preparing an EDTA mixed solution: weighing 2g of EDTA-Na₂And 3g L-cysteine are placed in a 1000mL beaker, 900mL of water is added, 2.5mol/LNaOH is used for adjusting the pH value to 13, the mixture is transferred into a 1000mL volumetric flask and the volume is fixed to the scale, and EDTA mixed solution is obtained;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 4min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:2, performing vortex mixing for 8min, performing ultrasonic treatment for 8min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, carrying out vortex mixing for 8min, carrying out ultrasonic treatment for 8min after full reaction, dissolving and diluting the sample with the EDTA mixed solution to scale, filtering the sample with a 0.45um filter membrane, carrying out constant volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series of gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 4

Preparing an EDTA mixed solution: weighing 2g of EDTA-Na₂And 5g of L-cysteine are placed in a 1000mL beaker, 900mL of water is added, 3mol/LNaOH is used for adjusting the pH value to 13, the mixture is transferred into a 1000mL volumetric flask and the volume is fixed to the scale, and EDTA mixed solution is obtained;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 6min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:2, performing vortex mixing for 10min, performing ultrasonic treatment for 10min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

preparation of standard solution: weighing 0.0105g of Saisen copper standard sample, placing the sample in a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, carrying out vortex mixing for 10min, carrying out ultrasonic treatment for 10min after full reaction, dissolving and diluting the sample with the EDTA mixed solution to scale, filtering the sample with a 0.45um filter membrane, carrying out constant volume to scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series of gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS determination;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 5

Preparing an EDTA mixed solution: weighing 2g of EDTA-Na₂And 3g L-cysteine are placed in a 1000mL beaker, 900mL of water is added, 3mol/LNaOH is used for adjusting the pH value to 14, the mixture is transferred into a 1000mL volumetric flask and the volume is fixed to the scale, and EDTA mixed solution is obtained;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 8min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:2, performing vortex mixing for 10min, performing ultrasonic treatment for 10min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

ion source parameters: drying gas: n is a radical of₂(ii) a Temperature of the drying gas: 350 ℃; flow rate of drying gas: 7L/min; sheath gas: n is a radical of₂(ii) a Temperature of sheath gas: 100 ℃; flow rate of sheath gas: 9L/min; atomizer pressure: 55 psi; nozzle voltage: 500V; capillary voltage: 4500V, EMV gain (-): 500V。

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 6

Preparing an EDTA mixed solution: 1.55g of EDTA-Na was weighed₂And 2.58g L-cysteine are put into a 1000mL beaker, 900mL of water is added, the pH value is adjusted to 12 by 3mol/LNaOH, the mixture is transferred into a 1000mL volumetric flask and the volume is fixed to the scale, and EDTA mixed solution is obtained;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 10min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:2, performing vortex mixing for 5min, performing ultrasonic treatment for 5min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Example 7

Preparing an EDTA mixed solution: 1.21g of EDTA-Na was weighed₂And 3.72g L-cysteine, putting into a 1000mL beaker, adding 900mL of water, adjusting the pH value to 12 by using 2mol/L NaOH, transferring into a 1000mL volumetric flask, and fixing the volume to the scale to obtain an EDTA mixed solution;

preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, performing ultrasonic treatment for 5min, putting 2.0mL in a 2000mL beaker, diluting the sample to 2000mL with aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with the prepared EDTA mixed solution according to the volume ratio of 1:1, performing vortex mixing for 5min, performing ultrasonic treatment for 5min after full reaction, filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution, and performing UPLC-MS/MS detection;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

time (minutes)	Flow ofPhase A (%)	Mobile phase B (%)
			0～2.5min	82％～90％	18％～10％
2.5～3.1min	90％～82％	10％～18％
			3.1～7.0min	82％	18％

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

Experimental example: to prove the scientificity and rationality of the invention, the following experimental studies of methodology were carried out:

the method comprises the following steps:

the method comprises the following steps: the method in the comparison file is adopted: the Saisen copper residue analysis method adopts sodium thiosulfate for hydrolysis, adopts an LC method for detection, and is formulated by combining the actual situation of the environmental research laboratory of our unit.

The instrument comprises the following steps: the high performance liquid chromatograph (Agilent 1260) is provided with a qualitative analysis workstation and a quantitative analysis workstation.

A chromatographic column: c18, inner diameter 150mm multiplied by 2.1mm, 3.5 μm;

reagent:

methanol: chromatographically pure, Merck corporation, (ii) C

Reag.Ph Eur，Lot：I0930107803)；

Acetonitrile: the American world is filled with original imported chromatographic grade reagent at 4L;

formic acid: the known mass fraction is: 95-98% of Shanghai test;

dimethylformamide (DMF): fuyu Fine chemical Co Ltd of Tianjin

Ultrapure water: resistivity, 18.2M Ω cm;

chromatographic and mass spectrometric conditions:

chromatographic conditions are as follows: after the instrument is in a stable state, injecting sample by using the series concentration standard working solution in the step (1), and detecting by LC, wherein:

liquid phase conditions:

a chromatographic column: c18(250mm 4.6mm 5um)

Column temperature: 40 ℃;

mobile phase: acetonitrile-0.01% acetic acid in water solution (30: 70 by volume);

flow rate: 0.7 mL/min;

sample introduction amount: 10 mu L of the solution;

detection wavelength: 313nm

A detector: DAD

(1) Preparation of a standard solution: weighing a proper amount of the Saisentong standard substance in a 100mL volumetric flask, dissolving the Saisentong standard substance by using DMF (dimethyl formamide) and fixing the volume to a scale, and preparing a standard stock solution with the concentration of 100 mg/L. Diluting the standard stock solution step by step to prepare standard working solution with the concentration of 0mg/L, 0.1mg/L, 0.5mg/L, 1.0mg/L, 2.0mg/L, 5mg/L, 10 mg/L;

(2) extraction: weighing 0.32g of 30% kasugand Saisentong suspending agent into a triangular flask with the plug of 100m, adding 2ml of 1mol/L sodium thiosulfate, shaking at the constant temperature of 50 ℃ for 2 hours, after shaking, adjusting the pH to 3 by using 2mol/L hydrochloric acid, transferring into a 250ml separating funnel, extracting for 2 times by using 50ml ethyl acetate (shaking vigorously for 1 minute), standing for layering, dehydrating the ethyl acetate layer by using anhydrous sodium sulfate, filtering the ethyl acetate layer into a round bottom flask (adding 3-low diethylene glycol), evaporating to dryness by rotary evaporation, and fixing the volume by using methanol;

(3) detecting by an instrument: and (3) after the state of the instrument is stable, injecting sample by using the series concentration standard working solution in the step (1), detecting by LC, and recording the peak area of the chromatogram.

(4) Establishment of a standard curve: adopting peak area quantification, taking the sample injection concentration as a horizontal coordinate and taking the peak area as a vertical coordinate, and drawing a standard curve;

and (4) conclusion: the content of the Saisen copper in the water is measured by the method, and the result data is as follows: the regression equation of the obtained standard curve is: y 48.1324x +0.431 and a correlation coefficient R ²1. The detection limit (measured by the signal-to-noise ratio S/N being more than or equal to 10) is 0.019mg/L, compared with the experimental result of the invention, the response value is low, the detection limit is high, the processing process of the test sample is complicated, and the research of the method is not carried out.

Method two

The method comprises the following steps: the method in the comparison file is adopted: CN 103592404B-a method for detecting the residual quantity of organic copper pesticides in fruits and vegetables, the method adopts an LC-MS/MS method to detect the residual quantity of organic copper pesticides in fruits and vegetables, and the method is formulated by combining the actual conditions of the environmental research laboratory of our unit.

The instrument comprises the following steps: an ultrahigh-pressure high-performance liquid chromatography-mass spectrometer (Agilent 1290-.

reagent:

methanol: chromatographically pure, Merck corporation, (ii) C

Reag.Ph Eur，Lot：I0930107803)；

formic acid: the known mass fraction is: 95-98% of Shanghai test;

Ultrapure water: resistivity, 18.2M Ω cm;

(1) preparing a test solution: 0.32g of 30% Chunlei Saisen copper suspension is weighed into a centrifuge tube, and 1g of Na is added₂S, fully performing vortex oscillation on a vortex oscillation instrument for 2min, then adding 15mL of methanol, performing vortex oscillation for 2min, performing ultrasonic extraction for 1h (shaking once every 20min during ultrasonic treatment), and centrifuging at 4000rpm on a centrifuge for 10 min. The extraction was repeated once by adding 5mL of methanol. And combining the two extracted supernatants, fixing the volume in a 25mL volumetric flask, and mixing uniformly. Taking 1mL of the extract, placing in a 2mL centrifuge tube, adding 50mg of PSA and 50mgC18 adsorbent, and centrifuging for 10min in an 13000rpm ultra-high speed centrifuge. Taking the supernatant, filtering with 0.45 μm filter membrane, and testing.

(2) UPLC-MS/MS detection

The detection conditions of the UPLC are as follows:

column temperature: 25 ℃;

mobile phase: phase A is acetonitrile and phase B is 0.1% formic acid solution in water. Gradient elution condition is 0-2 min, and 40% A is kept; for 2-4.5 min, 80-20% of A; keeping 80% A for 4.5-10 min; 10-12 min, 80% -40% A; keeping 40% A for 12-15 min;

flow rate: 0.20 mL/min;

sample introduction amount: 10 mu L of the solution;

the MS/MS conditions are as follows:

an ion source: electrospray ion source ESI;

the scanning mode is as follows: a negative ion source;

spraying voltage: 2800V;

capillary temperature: 350 ℃;

sheath gas pressure: 45 Arb;

auxiliary gas pressure: 15 Arb;

(3) establishment of a Standard Curve

Weighing a proper amount of the Saisentong standard substance into a 100mL volumetric flask, and dissolving the Saisentong standard substance with methanol to a constant volume to prepare 100mg/L stock solution. Diluting the Saisentong standard stock solution step by step to prepare standard working solution of 0.001mg/L, 0.005mg/L, 0.01mg/L, 0.05mg/L, 0.1mg/L, 0.5mg/L and 1.0 mg/L. And drawing a standard curve by taking the sample injection concentration as a horizontal coordinate and the peak area as a vertical coordinate.

The process of treating the test sample for the method is suitable for detecting vegetable and fruit solid objects, the operation for detecting the residual Thiessen copper in water in the natural environment is complicated, the direct addition of the solid reagent is poor in collateral breaking effect, the response value is low, and the research of the method is not carried out.

Method III

The following are experimental studies of the methodology of the present invention:

preparing an EDTA mixed solution: 1.21g of EDTA-Na was weighed₂And 3.72g L-cysteine are put into a 1000mL beaker, 900mL of water is added, 2mol/LNaOH is used for adjusting the pH value to 12, the mixture is transferred into a 1000mL volumetric flask and the volume is fixed to the scale, and EDTA mixed solution is obtained;

preparation of a test solution: weighing 0.3232g of a 30% kasugand Saisen copper suspending agent sample (wherein the mass molecule number of the Saisen copper is 25%, and the mass fraction of the kasugamycin is 5%) in a 100mL volumetric flask, adding aerated water to dilute the sample to a scale, carrying out ultrasonic treatment for 5min, putting 2.0mL of the sample in a 2000mL beaker, diluting the sample with the aerated water to the scale of 2000mL to obtain a Saisen copper aqueous solution with the concentration of 808 mu g/L, namely the Saisen copper aqueous solution to be detected, diluting the sample with the prepared EDTA mixed solution according to the volume ratio of 1:1, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min after full reaction, filtering the sample with a 0.45-micrometer filter membrane to obtain a derivatized Saisen copper solution, and carrying out UPLC-MS/MS detection;

preparation of standard solution: weighing 0.0105g of Saisen copper standard sample (omega 92 percent), placing the sample into a 100.00mL volumetric flask, dissolving and diluting the sample with EDTA mixed solution, carrying out vortex mixing for 5min, carrying out ultrasonic treatment for 5min after full reaction, dissolving and diluting the sample with the EDTA mixed solution to a scale, filtering the sample with a 0.45um filter membrane, fixing the volume to the scale to obtain standard sample stock solution with the Saisen copper concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution with the EDTA mixed solution to prepare standard working solution with the series of gradients of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and determining the sample by UPLC-MS/MS;

Wherein the HPLC operating conditions are as follows:

sample introduction volume: 3.0 mu L;

flow rate: 0.5 mL/min;

column temperature: 40 ℃;

mobile phase: acetonitrile + 0.1% formic acid water;

The MSD operating conditions were:

and (3) monitoring mode: MRM;

detection mode: a negative ion mode;

The MRM ion acquisition parameters are as follows:

*: for quantifying ions

1. Method investigation test

1.1. Linear test

Precisely sucking Thiessen copper reference substance solution 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and performing regression analysis on corresponding concentrations by using chromatographic peak areas of standard working solutions to obtain a linear equation of y being 12.67x-1.45, wherein R is²Results are shown in table 1 and figure 2, 0.9997.

The results show that the concentration of the Saisen copper sample in the range of 9.66 mu g/L-483.00 mu g/L shows good linear relation. The results are shown in Table 2.

TABLE 1 Thisen copper line Property test results

1.1.2 instrumental precision test

The reference substance solution of 48.30 mug/L prepared by the preparation method of the reference substance solution is taken, sample introduction is repeated for 6 times under the chromatographic conditions, the precision of the relative standard deviation verification method is calculated, the RSD (Saisentong) value is calculated to be 1.14%, the precision of the instrument is good, and the measurement result is shown in Table 2.

TABLE 2 Instrument precision test results

1.1.3 recovery rate by adding standard:

taking 5mL of Thiessen copper sample solution prepared by aeration water (the actual measurement concentration is 89.70 mug/L after the EDTA mixed solution 1:1 proportion treatment), adding 5mL of Thiessen copper standard solution prepared by aeration water (the actual measurement concentration is 106.72 mug/L after the EDTA mixed solution 1:1 proportion treatment), mixing the Thiessen copper sample solution and the Thiessen copper standard solution, and adding the EDTA mixed solution 1: treat at a ratio of 1, shake, and parallelize for 5 times. The test was carried out under the above-mentioned operating conditions of the apparatus, and the recovery rate of the spiked standard was calculated from the measured value according to the formula (1), and the average recovery rate (%) was: 86.89%, the results are shown in Table 3

Normalized recovery (%) as (detected amount/normalized amount) × 100% … … … formula (1)

TABLE 3 Thisen copper aerated water recovery test results

3.2.5 stability test

Preparing a test solution by using aerated water for stability test, placing at room temperature, respectively injecting samples for 0 hour, 24 hours and 48 hours under a proposed chromatographic condition, measuring peak areas, and calculating the concentration of the Thisen copper, wherein the result shows that the Thisen copper can be maintained at more than 80% of the concentration of the Thisen copper within 0 hour within 24 hours, and the stability test result is shown in table 4.

TABLE 4 stability test results

1.1.4 detection and quantitation limits

The control solution prepared by the preparation method of the control solution is diluted into standard use solution with the concentration of 0.97 mu g/L by EDTA mixed solution, the measurement is repeated for 6 times, and LOD and LOQ values are calculated according to S/N values, and the test result shows that the LOD of the established method for the Saisen copper is 0.427 mu g/L, and the LOQ is 1.422 mu g/L. The detailed results are shown in Table 5.

TABLE 5 analytical methods detection limit and quantitation limit test results

1.2 method one, method two and method three experimental results are summarized and compared.

1.2.1 comparison of regression equations of Standard curves

And (4) conclusion: the method using the comparison file, namely the method I, obtains a linear equation Y of 48.1324X +0.431 and a correlation coefficient R in a higher concentration range of 0.01mg/L to 10mg/L²Method II obtains linear equation Y of 3.465 x 10 in the concentration range of 0.001mg/L to 1.0mg/L²X+16.29×10⁴Coefficient of correlation R²Method three is the preferred method of the present invention, at lower concentration range 9.66ug/L to 483.00ug/L, the linear equation Y is 12.67X-1.45, the correlation coefficient R2 is 0.9997, and method three is the most preferred method.

1.2.2 comparison of detection Limit with quantification Limit

And (4) conclusion: the first method and the second method are comparative experiments, and the detection limit of the first method is 0.019mg/L, the quantification limit is 0.310mg/L, the detection limit of the second method is 0.037mg/L, and the quantification limit is 0.1430mg/L, which are higher than the detection limit of the third method of the preferred method of the invention, namely 0.427 mu g/L and the quantification limit is 1.422 mu g/L.

To summarize: the invention has good linear relation in the lower concentration range of the Saisen copper of 9.66 ug/L-483.00 ug/L, and the concentration range of the method using the comparison file is higher, specifically 0.01 mg/L-10 mg/L; the detection limit of the invention can reach 0.427 mug/L, the quantification limit reaches 1.422 mug/L, while the detection limit of the method using the comparison file is 0.037mg/L, and the quantification limit is 0.143mg/L, which are superior to the comparison file; the preparation process of the test sample is simple to operate, the test sample solution is relatively stable within 24 hours, the precision of the instrument is high, the repeatability of the reference substance is good, the RSD% value is 1.14%, and the method can effectively detect the low-content Thisen copper in water.

While the invention has been described in detail in the foregoing by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that certain changes and modifications may be made therein based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A method for detecting Saisentong copper in water by using a UPLC-MS/MS method is characterized by comprising the following steps:

1) preparing an EDTA mixed solution: weighing 0.5-2 g of EDTA-Na₂Placing 1-5 g L-cysteine into a 1000mL beaker, adding 900mL of water, adjusting the pH to be 10-14 by using 1-3 mol/L NaOH, transferring the solution into a 1000mL volumetric flask, and fixing the volume to a scale to obtain an EDTA mixed solution;

2) preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute the sample to a scale, carrying out ultrasonic treatment for 2-10 min, taking 2.0mL of the sample in a 2000mL beaker, diluting the sample to 2000mL of scale with the aeration water to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, taking the Thisen copper aqueous solution to be detected, diluting the Thisen copper aqueous solution with an EDTA mixed solution according to the volume ratio of 1: 1-1: 3, carrying out vortex mixing for 5-20 min, carrying out ultrasonic treatment for 5-20 min after full reaction, dissolving and diluting the Thisen copper aqueous solution to a scale with the EDTA mixed solution, and filtering the solution with a 0.45um filter membrane to obtain the derivatized Thi;

3) preparation of standard solution: weighing a Saisentong standard sample, placing the Saisentong standard sample into a 100.00mL volumetric flask, dissolving and diluting the Saisentong standard sample by using an EDTA mixed solution, carrying out vortex mixing for 5-20 min, carrying out ultrasonic treatment for 5-20 min, fixing the volume to a scale to obtain a standard sample stock solution with the Saisentong concentration of 96.60mg/L, sucking a proper standard sample stock solution, diluting the standard sample stock solution by using the EDTA mixed solution to prepare a standard working solution with the series gradient of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS measurement;

4) measurement and calculation of results: setting instrument parameters, and performing UPLC-MS/MS measurement on a reference solution and a test solution after the instrument is stable, wherein the UPLC operation conditions are as follows: 1) A chromatographic column: agilent Hilic Plus RRHD 2.1 × 50mm, 1.8 μm; 2) sample introduction volume: 3.0 mu L; 3) flow rate: 0.5 mL/min; 4) column temperature: 40 ℃; 5) elution solvent and procedure: eluting solvent: mobile phase A: acetonitrile; mobile phase B: 0.1% formic acid water; the elution procedure was:

time (min) mobile phase A (%) mobile phase B (%)

0～2.5min 82%～90% 18%～10%

2.5～3.1min 90%～82% 10%～18%

3.1～7.0min 82% 18%

The MSD operating conditions were: 1) and (3) monitoring mode: MRM; 2) a negative ion mode; 3) ion source parameters: drying gas: n is a radical of₂(ii) a Temperature of the drying gas: 350 ℃; flow rate of drying gas: 7L/min; sheath gas: n is a radical of₂(ii) a Temperature of sheath gas: 100 ℃; flow rate of sheath gas: 9L/min; atomizer pressure: 55 psi; nozzle voltage: 500V; capillary voltage: 4500V, EMV gain-: 500V;

monitoring time is 0-7.0 min, the name of the compound is Thisen copper derivative, parent ion 277, ion quantitative ion 144.2, voltage is 55V, collision energy is 0eV, and cell acceleration voltage is 5V; when monitoring is carried out for 0-7.0 min, the name of the compound is Thiessen copper derivative, parent ion 277, ion 132.1, voltage 55V, collision energy 8eV, and cell acceleration voltage 5V; when monitoring is carried out for 0-7.0 min, the name of the compound is Thiessen copper derivative, the parent ion 277 is shown, the ionic ion 58.2 is shown, the voltage is 55V, the collision energy is 40eV, and the cell acceleration voltage is 5V;

and recording a chromatogram, taking the content of the Thisen copper derivative as the content of the Thisen copper, and calculating according to an external standard method.

2. The method for detecting Saisentong copper in water by using the UPLC-MS/MS method as claimed in claim 1, which is characterized in that: the method comprises the following steps:

1) preparing an EDTA mixed solution: weighing 1-1.5 g of EDTA-Na₂Adding 900mL of water into a 1000mL beaker containing 2-4 g L-cysteine, adjusting the pH value to 11-13 by using 1.5-2.5 mol/LNaOH, transferring the beaker into a 1000mL volumetric flask, and fixing the volume to a scale to obtain an EDTA mixed solution;

2) preparation of a test solution: weighing 0.3232g of 30% Chunlei and Thisen copper suspending agent sample in a 100mL volumetric flask, adding aeration water to dilute to a scale, performing ultrasonic treatment for 3-8 min, taking 2.0mL in a 2000mL beaker, diluting with aeration water to 2000mL to obtain a Thisen copper aqueous solution with the concentration of 808 mug/L, namely the Thisen copper aqueous solution to be detected, taking the Thisen copper aqueous solution to be detected, diluting with an EDTA mixed solution according to the volume ratio of 1:2, performing vortex mixing for 5-10 min, performing ultrasonic treatment for 5-10 min after full reaction, dissolving with the EDTA mixed solution to dilute to a scale, and filtering with a 0.45um filter membrane to obtain the derivatized Thisen copper solution;

3) preparation of standard solution: weighing a Saisentong standard sample, placing the Saisentong standard sample into a 100.00mL volumetric flask, dissolving and diluting the sample by using EDTA mixed solution, carrying out vortex mixing for 5-10 min, carrying out ultrasonic treatment for 5-10 min, fixing the volume to a scale to obtain standard sample stock solution with the Saisentong concentration of 96.60mg/L, sucking proper standard sample stock solution, diluting the standard sample stock solution by using the EDTA mixed solution to prepare standard working solution with the series gradient of 9.66 mu g/L, 19.32 mu g/L, 48.30 mu g/L, 96.60 mu g/L, 193.20 mu g/L and 483.00 mu g/L, and waiting for UPLC-MS/MS measurement;

4) measurement and calculation of results: setting instrument parameters, carrying out UPLC-MS/MS measurement on the reference substance solution and the test substance solution after the instrument is stable, and recording the peak area of the chromatogram; and obtaining the content of the Thiessen copper derivative in the test solution, and calculating by taking the content of the Thiessen copper derivative as the content of the Thiessen copper.

3. The method for detecting Saisentong copper in water by using the UPLC-MS/MS method as claimed in claim 1, which is characterized in that: the method has the detection limit LOD of 0.427 mu g/L and the LOQ of 1.422 mu g/L for the Thiessen copper.