CN109283276B - Gas chromatography for determining residues of eight phenoxy carboxylic acid herbicides in corn - Google Patents
Gas chromatography for determining residues of eight phenoxy carboxylic acid herbicides in corn Download PDFInfo
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Abstract
The invention relates to a trace harmful substance analysis and detection method, in particular to a gas chromatography method for determining trace 2, 4-dichlorophenoxyacetic acid, 2, 4-dichlorophenoxypropionic acid, 2, 4-dichlorophenoxybutyric acid and other eight phenoxy carboxylic acid herbicide residues in corn. The method comprises the steps of extracting with an alkaline 10% acetone aqueous solution, enriching a target compound in an extracting solution with a novel p-toluenesulfonate-magnesium aluminum type hydrotalcite roasted product adsorbent, dissolving the adsorbent with an acid to completely elute the target compound, efficiently extracting the compound with a small amount of an organic solvent, and rapidly analyzing and determining by a gas chromatography after derivatization. The novel adsorbent adopted by the method realizes rapid and efficient adsorption on the target object by adopting a dispersed solid phase extraction mode, and the enrichment is efficient; the complete desorption of the target can be realized by using the acid to dissolve the adsorbent; only a small amount of organic solvent is suitable for extraction, and compared with a liquid-liquid extraction method which needs a large amount of organic solvent, the method has the advantages of safety, environmental protection and economic advantage.
Description
Technical Field
The invention relates to a method for analyzing and detecting harmful trace substances, in particular to a gas chromatography for simultaneously determining trace 2, 4-dichlorophenoxyacetic acid, 2, 4-dichlorophenoxypropionic acid, 2, 4-dichlorophenoxybutyric acid, 2,4, 5-trichlorophenoxyacetic acid, 2,4, 5-trichlorophenoxypropionic acid, 2-methyl-4-chlorophenoxypropionic acid, 2-methyl-4-chlorophenoxyacetic acid and 2-methyl-4-chlorophenoxybutyric acid which are eight phenoxy carboxylic acid herbicide residues in corn.
Background
The phenoxy carboxylic acid herbicides are the second most sold and used amount in the world and are also the first selective herbicides put into commercial production, and can be absorbed by stems, leaves and root systems of plants, so that the herbicides are used as stem and leaf treatment agents in agricultural production, are widely applied to cereal crops, coniferous forests, uncultivated areas, pastures and the like, and can be used for preventing and removing broadleaf weeds such as xanthium sibiricum, convolvulus, amaranthus, quinoa, purslane, green Chinese cabbage and the like.
Phenoxy carboxylic acid herbicides are divided into two different series according to the difference of the bulk compound of the active ingredients. 2, 4-dichlorophenoxyacetic acid, 2, 4-dichlorophenoxypropionic acid, etc. containing 2, 4-dichlorophenol as main component; a compound is 2-methyl-4-chlorophenoxypropionic acid, 2-methyl-4-chlorophenoxyacetic acid, etc. with o-cresol as main component. Phenoxy carboxylic acid herbicides belong to low-toxicity pesticides, but metabolites of phenoxy carboxylic acid herbicides can cause certain harm to organisms. Research shows that the compounds and metabolites thereof show placental toxicity to animals, and plants treated by the compounds can cause acute toxicity when used by animals. Due to the wide range of application and the large amount of application of the herbicides, the implications of safety on animals, human bodies and the environment are attracting increasing attention.
Currently, there are many methods for analyzing and detecting phenoxy carboxylic acid herbicide residues in water, soil and plant food, and the domestic main detection standards include "liquid chromatography/tandem mass spectrometry for determining phenoxy carboxylic acid herbicide in water quality" HJ 770-2015-. In conclusion, the main technical means related to the detection of phenoxy carboxylic acid herbicides is a chromatography and mass spectrometry combined method, and the pretreatment of the detection of the herbicides in food is mainly focused on two methods, namely liquid-liquid extraction and solid-phase extraction. However, the liquid-liquid extraction method has the defect that a large amount of organic solvent is required; the solid phase extraction method has the problems of limited types of solid phase extraction columns, few types of commercialized products and lack of special selective adsorption filler.
In recent years, the inventor research team has conducted extensive research on Layered Double hydroxide metal oxides (LDHs) and modified materials thereof, prepared different types of intercalated anion modified LDHs and baked product (LDO) materials thereof, and based on the preparation, application research on screening, investigation and optimization of adsorption enrichment performance of different target compounds is conducted by using these synthetic materials. The inventor carries out related research on adsorption and desorption of partial phenoxy carboxylic acid herbicides by applying the p-toluenesulfonate-magnesium-aluminum type hydrotalcite adsorbent in earlier research, and evaluates the adsorption and desorption effects by adopting a high performance liquid chromatography.
Disclosure of Invention
The method aims to overcome the defect that a large amount of organic solvent is needed in the liquid-liquid extraction method in the pretreatment of detecting the trace phenoxy carboxylic acid herbicides in the existing plant-derived food; the invention aims to solve the technical problem of providing a gas chromatography which is based on the dispersed solid phase extraction and rapid adsorption of a novel p-toluenesulfonate-magnesium-aluminum type hydrotalcite roasted product adsorbent and is suitable for detecting the residue of eight trace phenoxy carboxylic acid herbicides in corn.
The invention achieves the above object by the following technical means.
The gas chromatography for determining the residues of eight phenoxy carboxylic acid herbicides in corn is characterized by comprising the following steps of:
step 1 extraction and adsorption of the compound: grinding and sealing a corn sample, storing at 4 ℃ for later use, weighing 5.00g of a crushed sample in a 50mL plastic centrifuge tube with a plug when in use, adding 25mL of alkaline 10% acetone aqueous solution with the pH of 9.0 into the centrifuge tube, homogenizing and extracting at the high speed of 15000rpm for 1min, centrifuging, transferring a supernatant to another 100mL plastic centrifuge tube with a plug, re-extracting once, combining extracting solutions, adding 0.50g of p-toluenesulfonate-magnesium aluminum type hydrotalcite roasting product adsorbent into the extracting solution, and oscillating for 15min to enable the adsorbent to adsorb eight target compounds in the extracting solution;
step 2 desorption of compound: centrifuging the centrifuge tube with the plug, removing supernatant, adding 5.00mL of hydrochloric acid solution to dissolve the solid adsorbent, and finishing desorption of the adsorbed compound;
step 3, extraction and derivatization of compounds: adding a certain amount of anhydrous sodium sulfate and an organic solvent into the centrifuge tube for extraction, performing vortex and centrifugation, taking supernatant into a derivatization bottle, adding 1.0mL of 14% boron trifluoride-methanol solution into the derivatization bottle, sealing, performing vortex, and placing the derivatization bottle into a 70 ℃ water bath for reaction for 30-40 min to complete the derivatization process;
analytical testing of the compound of step 4: placing the derivative bottle in a refrigerator below-10 ℃ for cooling for 10min to 15min, adding 0.5mL of saturated sodium chloride aqueous solution and 0.5g of sodium bicarbonate powder into the derivative bottle, swirling, adding 2.0g of anhydrous sodium sulfate into the derivative bottle, swirling and centrifuging, then completely taking the upper organic solution into a glass centrifuge tube, blowing nitrogen to the glass centrifuge tube at 40 ℃ for drying, adding 2.00mL of acetone into the glass centrifuge tube for constant volume, swirling, absorbing the upper organic solution, filtering, and then performing analysis and test by using a gas chromatography according to the following conditions:
a) a chromatographic column: HP-5 capillary column, 30m × 0.32mm, 0.25 μm film thickness; constant flow mode, column flow rate: 2.00 mL/min.
b) Sample inlet temperature: 250 ℃; and (3) sample introduction mode: no shunt sampling; sample introduction amount: 2 mu L of the solution; tail gas blowing flow: 60 mL/min.
c) Temperature rising procedure: 60 deg.C (keeping 1min), heating to 150 deg.C at 15 deg.C/min (keeping 1min), heating to 250 deg.C at 10 deg.C/min (keeping 1min), and running at 300 deg.C (keeping 3 min).
d) A detector: microelectronic capture detector (μ ECD), temperature: 325 ℃.
e) Carrier gas: high-purity nitrogen (the purity is more than or equal to 99.999%).
Wherein the content of the first and second substances,
the eight phenoxy carboxylic acid herbicides in step 1 are 2, 4-dichlorophenoxyacetic acid, 2, 4-dichlorophenoxypropionic acid, 2, 4-dichlorophenoxybutyric acid, 2,4, 5-trichlorophenoxyacetic acid, 2,4, 5-trichlorophenoxypropionic acid, 2-methyl-4-chlorophenoxypropionic acid, 2-methyl-4-chlorophenoxyacetic acid and 2-methyl-4-chlorophenoxybutyric acid, and the alkaline 10% acetone aqueous solution is adjusted to have a pH of 9.0 by using 0.01mol/L sodium hydroxide aqueous solution.
The hydrochloric acid solution in the step 2 is prepared from concentrated hydrochloric acid and water according to the volume ratio of 1: 1.
The amount of anhydrous sodium sulfate added in step 3 was 2.0g, and the organic extraction solvent was 5mL of ethyl acetate.
The filter membrane in the step 4 is an organic phase filter membrane with the aperture of 0.22 mu m.
In the above steps, the vortex is 1min to 2min, and the centrifugation is carried out for 3min at the rotating speed of 4500 rpm.
In the previous research, the inventor uses a p-toluenesulfonate-magnesium-aluminum type hydrotalcite adsorbent to perform adsorption and desorption research on part of phenoxy acid herbicides in water, and because the corn matrix and the water matrix have larger difference, more organic impurities are brought in the extraction process, so that the requirements on the types and the use amount of the adsorbents are different, the inventor emphasizes on optimizing the key factor of the use amount of the adsorbent under the condition of fixing other factors such as the sample amount, the extraction solution and the like in the development process of the method, and finds that the use of 0.50g of the adsorbent can completely adapt to the adsorption requirement of a 5.00g sample. As the phenoxy carboxylic acid herbicide has the characteristics of high polarity and high water solubility, the alkaline acetone aqueous solution with the adjusted pH value is used as the extractant in the experiment, so that the extraction of the target object in the corn matrix can be completed under the condition of using less organic solvent.
In the experiment, the inventor compares methyl esterification derivatization methods and conditions of various phenoxy carboxylic acid herbicides by combining the precondition of adsorbing a baked product of the methylbenzenesulfonate-magnesium aluminum type hydrotalcite, selectively uses a boron trifluoride-methanol method to perform derivatization on a target substance, and optimizes the derivatization conditions. In addition, as the eight selected phenoxy carboxylic acid herbicides contain chlorine elements with good response values on an electron capture detector, the gas chromatography with the electron capture detector is selected for detection in the experiment, and the chromatographic conditions are optimized.
Meanwhile, in consideration of quantitative accuracy of the target object, the method quantifies the target object by adopting the matrix correction curve on the premise that the isotope of the target object cannot be obtained so as to quantify the target object by an isotope internal standard method, so that systematic errors are eliminated as much as possible, and the quantitative accuracy is improved.
The invention has the advantages that:
(1) the novel adsorbent adopted by the invention can quickly adsorb trace phenoxy carboxylic acid herbicides in the extracting solution by adopting a dispersed solid phase extraction mode on the roasted product of the methylbenzenesulfonate-magnesium-aluminum type hydrotalcite, so that the enrichment is efficient;
(2) according to the invention, by utilizing the characteristic that the p-toluenesulfonate-magnesium-aluminum type hydrotalcite calcined product adsorbent can be dissolved in acid, the adsorbent after adsorbing the target object is dissolved by using a hydrochloric acid solution, so that the target object can be completely desorbed from the adsorbent;
(3) the method is only suitable for using a small amount of organic solvent as the extraction solvent of the target object, and has the advantages of safety, environmental protection and economic advantages compared with the liquid-liquid extraction method which needs to use a large amount of organic solvent.
Drawings
FIG. 1 is a chromatogram of a standard solution of a substrate of eight phenoxy carboxylic herbicides in an embodiment, at a concentration of 200.0. mu.g/L, wherein 1 is 2-methyl-4-chlorophenoxypropionic acid, 2-methyl-4-chlorophenoxyacetic acid, 3 is 2, 4-dichlorophenoxyacetic acid, 4 is 2, 4-dichlorophenoxypropionic acid, 5 is 2,4, 5-trichlorophenoxypropionic acid, 6 is 2-methyl-4-chlorophenoxybutyric acid, 7 is 2,4, 5-trichlorophenoxyacetic acid, and 8 is 2, 4-dichlorophenoxybutyric acid.
Detailed Description
For further disclosure, but not limitation, the present invention is described in further detail below with reference to examples.
(1) The reagent medicines involved in the embodiments of the present invention are as follows:
2, 4-dichlorphenoxyacetic acid, 2, 4-dichlorphenoxypropionic acid, 2, 4-dichlorphenoxybutyric acid and the like, the purity of the total eight compounds is more than or equal to 98.0 percent, Germany Dr.Ehrensorfer company;
acetone, ethyl acetate, anhydrous sodium sulfate, sodium bicarbonate, analytically pure, group of national medicine;
hydrochloric acid, super pure, group of national medicine; the water is first-grade water meeting the GB/T6682 specification.
14% boron trifluoride in methanol, Sigma.
Blank corn kernels and fresh corn kernels for experiments are purchased from Fuqing local supermarkets, wherein the corn kernels are ground, the edible particle parts of the fresh corn kernels are taken down and crushed, and the ground corn kernels are sealed and stored in a refrigerator at 4 ℃ for later use.
(2) The instruments involved in the examples of the present invention are as follows:
KH-75A type electric heating constant temperature air-blast drying oven, Kangheng instruments ltd, Guangzhou;
model 7890B gas chromatograph equipped with an electron capture detector, Agilent technologies, Inc. USA.
(3) Analysis and test conditions of a gas chromatograph:
a) a chromatographic column: HP-5 capillary column, 30m × 0.32mm, 0.25 μm film thickness; constant flow mode, column flow rate: 2.00 mL/min.
b) Sample inlet temperature: 250 ℃; and (3) sample introduction mode: no shunt sampling; sample introduction amount: 2 mu L of the solution; tail gas blowing flow: 60 mL/min.
c) Temperature rising procedure: 60 deg.C (keeping 1min), heating to 150 deg.C at 15 deg.C/min (keeping 1min), heating to 250 deg.C at 10 deg.C/min (keeping 1min), and running at 300 deg.C (keeping 3 min).
d) A detector: microelectronic capture detector (μ ECD), temperature: 325 ℃.
e) Carrier gas: high-purity nitrogen (the purity is more than or equal to 99.999%).
(4) Preparation of matrix calibration curve and determination of detection limit and quantitative limit
Accurately weighing the phenoxy carboxylic acid herbicide, dissolving the phenoxy carboxylic acid herbicide by methanol to a constant volume, and preparing a standard stock solution with the concentration of 1000mg/L, and storing the solution at the temperature of-4 ℃. When in use, the standard stock solution is gradually diluted by deionized water to prepare standard use solution with the concentration gradient of 10.0 mug/L, 20.0 mug/L, 40.0 mug/L, 100.0 mug/L and 200.0 mug/L.
Taking five 50mL plastic centrifuge tubes with plugs, weighing 5.00g of blank samples respectively, adding 2.00mL of the standard use solution respectively, adding 25mL of alkaline 10% acetone aqueous solution with Ph being 9.0 into the centrifuge tubes, homogenizing and extracting at a high speed of 15000rpm for 1min, centrifuging, transferring the supernatant into another 100mL plastic centrifuge tube with plugs, re-extracting once, combining the extracting solutions, adding 0.50g of p-toluenesulfonate-magnesium aluminum type hydrotalcite calcined product adsorbent into the extracting solution, and oscillating for 15min to enable the adsorbent to adsorb eight target compounds in the extracting solution;
centrifuging the centrifuge tube with the plug, removing supernatant, adding 5.00mL of hydrochloric acid solution to dissolve the solid adsorbent, and finishing desorption of the adsorbed compound;
adding 2.0g of anhydrous sodium sulfate and 5.00mL of ethyl acetate into the centrifuge tube, carrying out vortex and centrifugation, taking supernatant into a derivatization bottle, adding 1.0mL of 14% boron trifluoride-methanol solution, sealing, carrying out vortex, and placing the derivatization bottle into a water bath at 70 ℃ for reaction for 30min to complete the derivatization process;
placing the derivatization bottle in a refrigerator below-10 ℃ for cooling for 10min, adding 0.5mL of saturated sodium chloride aqueous solution and 0.5g of sodium bicarbonate powder into the derivatization bottle, swirling, adding 2.0g of anhydrous sodium sulfate into the derivatization bottle, swirling and centrifuging, then completely taking the upper organic solution into a glass centrifuge tube, blowing nitrogen to the glass centrifuge tube at 40 ℃ for near drying, adding 2.00mL of acetone into the glass centrifuge tube for constant volume, swirling, absorbing the upper organic solution, passing the upper organic solution through a 0.22 mu m organic filter membrane, and then applying gas chromatography for analysis and test.
The above vortex was 1min and the centrifugation was carried out at 4500rpm for 3 min.
And (3) drawing a matrix standard curve by taking the concentration of the phenoxy carboxylic acid herbicide in the sample solution as an X axis and the chromatographic peak area of the phenoxy carboxylic acid herbicide derivative on a gas chromatograph as a Y axis, and quantifying by using an external standard method.
The triple value of the signal-to-noise ratio S/N is taken as the detection limit of the method (LOD, LOD is 3S/N), the ten times of the signal-to-noise ratio S/N is taken as the quantification limit of the method (LOQ, LOQ is 10S/N), and the detection limit and the quantification limit of each compound in water are calculated by combining the volume of the added matrix.
The relevant parameters of the matrix standard curve, LOD and LOQ are shown in Table 1.
TABLE 1 information on the matrix standard curve, detection limit and quantification limit of eight phenoxy carboxylic acid herbicides
5) Synthesis of p-methyl benzene sulfonate-magnesium-aluminum type hydrotalcite calcined product adsorbent
In order to enable those skilled in the art to repeatedly carry out the relevant experiments of the present invention, a method for synthesizing the p-toluenesulfonate-magnesium aluminum type hydrotalcite calcined product adsorbent, which is a key substance used in the present invention, is now provided as follows:
the reagent and the drug related to the synthesis of the adsorbent are as follows:
sodium p-toluenesulfonate, analytically pure, pharmaceutical group;
Mg6Al2(OH)16CO3·4H2o, analytical grade, Aldrich, usa.
② the apparatus related to the synthesis of the adsorbent is as follows:
an EXCEL type microwave digestion instrument, Shanghai Yao Instrument science and technology development Co., Ltd., digestion tank volume of 100 mL; microwave muffle furnace (sintering furnace), CEM corporation, usa; model VD53 vacuum drying cabinet, German Bindd technologies; HJ-5 multifunctional constant temperature stirrer, Kantai Ronghua Instrument manufacturing Co., Ltd; FS-12 type separatory funnel oscillator, New optical technology, Japan; 3K-15 type centrifuge, sigma technologies, germany; BF518945C-1 model box resistance furnace (muffle furnace), Saimer Feishell science, USA.
The concrete steps of synthesizing the adsorbent are as follows:
(a) first roasting: mg of purchased Mg-Al type hydrotalcite6Al2(OH)16CO3·4H2Placing O in a muffle furnace, heating at a heating rate of 5 ℃/min to 500 ℃, and roasting for 6h to obtain a roasted product Mg6Al2O8(OH)2；
(b) Weighing: 13.509g of intercalation agent sodium p-toluenesulfonate and 7.236g of roasting product Mg are weighed in a microwave digestion tank6Al2O8(OH)2。
(c) Microwave crystallization hydrothermal synthesis: boiling deionized water and keeping for 30min, adding 60mL into the microwave digestion tank filled with the intercalation agent and the roasting product, sealing, placing the microwave digestion tank into a microwave digestion instrument, and performing microwave heating at 150 ℃ for 30min to complete synthesis;
(d) washing and drying: pouring out all solids and liquid in the microwave tank, heating and stirring with deionized water boiled for more than 30min to remove carbon dioxide, shaking, washing, centrifuging, vacuum drying at 90 deg.C for 12h, grinding, and storing.
(e) And (3) second roasting: and (3) placing the prepared material in a muffle furnace, heating to 500 ℃ at a heating rate of 5 ℃/min, and roasting for 6h to obtain the p-toluenesulfonate-magnesium aluminum type hydrotalcite roasted product adsorbent.
Example 1
In this example 1, a blank corn kernel was used as a sample matrix to perform a labeling recovery experiment to verify the feasibility of the method of the present invention, and the method was performed according to the following steps:
1. extraction and adsorption of the compounds:
weighing 5.00g of blank sample in a 50mL plastic centrifuge tube with a plug, respectively adding an appropriate amount of standard use solution to prepare a three-level six-parallel standard sample, adding 25mL of alkaline 10% acetone aqueous solution with pH of 9.0 into the centrifuge tube, homogenizing and extracting at a high speed of 15000rpm for 1min, centrifuging, transferring the supernatant to another 100mL plastic centrifuge tube with a plug, re-extracting once, combining the extract, adding 0.50g of p-toluenesulfonate-magnesium aluminum type hydrotalcite calcined product adsorbent into the extract, and oscillating for 15min to make the adsorbent adsorb eight target compounds in the extract;
2. desorption of the compound:
centrifuging the centrifuge tube with the plug, removing supernatant, adding 5.00mL of hydrochloric acid solution to dissolve the solid adsorbent, and finishing desorption of the adsorbed compound;
3. extraction and derivatization of compounds:
adding 2.0g of anhydrous sodium sulfate and 5.00mL of ethyl acetate into the centrifuge tube, carrying out vortex and centrifugation, taking supernatant into a derivatization bottle, adding 1.0mL of 14% boron trifluoride-methanol solution, sealing, carrying out vortex, and placing the derivatization bottle into a water bath at 70 ℃ for reaction for 30min to complete the derivatization process;
4. analysis and test:
placing the derivatization bottle in a refrigerator below-10 ℃ for cooling for 10min, adding 0.5mL of saturated sodium chloride aqueous solution and 0.5g of sodium bicarbonate powder into the derivatization bottle, swirling, adding 2.0g of anhydrous sodium sulfate into the derivatization bottle, swirling and centrifuging, then completely taking the upper organic solution into a glass centrifuge tube, blowing nitrogen to the glass centrifuge tube at 40 ℃ for near drying, adding 2.00mL of acetone into the glass centrifuge tube for constant volume, swirling, absorbing the upper organic solution, passing the upper organic solution through a 0.22 mu m organic filter membrane, and then applying gas chromatography for analysis and test.
The above vortex was 1min and the centrifugation was carried out at 4500rpm for 3 min.
The parameters relevant to the spiking recovery experiment of example 1 are shown in Table 2.
TABLE 2 corn grain sample add-on concentration and recovery test data (n ═ 6)
Example 2
In this example 2, a blank fresh-eating corn kernel is used as a sample matrix to perform a labeling recovery experiment to verify the feasibility of the method, and the method is processed according to the following steps:
1. extraction and adsorption of the compounds:
weighing 5.00g of blank sample in a 50mL plastic centrifuge tube with a plug, respectively adding an appropriate amount of standard use solution to prepare a three-level six-parallel standard sample, adding 25mL of alkaline 10% acetone aqueous solution with pH of 9.0 into the centrifuge tube, homogenizing and extracting at a high speed of 15000rpm for 1min, centrifuging, transferring the supernatant to another 100mL plastic centrifuge tube with a plug, re-extracting once, combining the extract, adding 0.50g of p-toluenesulfonate-magnesium aluminum type hydrotalcite calcined product adsorbent into the extract, and oscillating for 15min to make the adsorbent adsorb eight target compounds in the extract;
2. desorption of the compound:
centrifuging the centrifuge tube with the plug, removing supernatant, adding 5.00mL of hydrochloric acid solution to dissolve the solid adsorbent, and finishing desorption of the adsorbed compound;
3. extraction and derivatization of compounds:
adding 2.0g of anhydrous sodium sulfate and 5.00mL of ethyl acetate into the centrifuge tube, carrying out vortex and centrifugation, taking supernatant into a derivatization bottle, adding 1.0mL of 14% boron trifluoride-methanol solution, sealing, carrying out vortex, and placing the derivatization bottle into a water bath at 70 ℃ for reaction for 40min to complete the derivatization process;
4. analysis and test:
placing the derivatization bottle in a refrigerator below-10 ℃ for cooling for 15min, adding 0.5mL of saturated sodium chloride aqueous solution and 0.5g of sodium bicarbonate powder into the derivatization bottle, swirling, adding 2.0g of anhydrous sodium sulfate into the derivatization bottle, swirling and centrifuging, then completely taking the upper organic solution into a glass centrifuge tube, blowing nitrogen to the glass centrifuge tube at 40 ℃ for near drying, adding 2.00mL of acetone into the glass centrifuge tube for constant volume, swirling, absorbing the upper organic solution, passing the upper organic solution through a 0.22 mu m organic filter membrane, and then applying gas chromatography for analysis and test.
The above vortex was 1min and the centrifugation was carried out at 4500rpm for 3 min.
The parameters relevant to the spiking recovery experiment of example 2 are shown in Table 3.
TABLE 3 fresh corn grain sample add-on concentration and recovery data (n ═ 6)
The above-mentioned embodiments only express the embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the spirit of the invention, which falls within the scope of the invention, and therefore the scope of the patent of the invention shall be governed by the appended claims.
Claims (6)
1. The gas chromatography for determining the residues of eight phenoxy carboxylic acid herbicides in corn is characterized by comprising the following steps of:
(1) extraction and adsorption of the compounds: grinding and sealing a corn sample, storing at 4 ℃ for later use, weighing 5.00g of a crushed sample in a plastic centrifuge tube with a plug when in use, adding 25mL of alkaline 10% acetone aqueous solution into the centrifuge tube, homogenizing and extracting at high speed, centrifuging, transferring the supernatant into another plastic centrifuge tube with a plug, re-extracting once, combining extracting solutions, adding 0.50g of p-toluenesulfonate-magnesium aluminum type hydrotalcite roasted product adsorbent into the extracting solution, shaking for a certain time to make the adsorbent adsorb 2, 4-dichlorophenoxyacetic acid, 2, 4-dichlorophenoxypropionic acid, 2, 4-dichlorophenoxybutyric acid, 2,4, 5-trichlorophenoxyacetic acid, 2,4, 5-trichlorophenoxypropionic acid, 2-methyl-4-chlorophenoxypropionic acid, 2-methyl-4-chlorophenoxyacetic acid and 2-methyl-4-chlorophenoxybutyric acid in the extracting solution;
(2) desorption of the compound: centrifuging the plastic centrifuge tube with the plug, removing supernatant, adding a certain amount of hydrochloric acid solution to dissolve the solid adsorbent, and finishing desorption of the adsorbed compound;
(3) extraction and derivatization of compounds: adding a certain amount of anhydrous sodium sulfate and an organic solvent into the centrifuge tube for extraction, performing vortex and centrifugation, taking supernatant into a derivatization bottle, adding 1.0mL of 14% boron trifluoride-methanol solution into the derivatization bottle, sealing, performing vortex, and placing the derivatization bottle into a 70 ℃ water bath for reaction for 30-40 min to complete the derivatization process;
(4) analytical testing of compounds: placing the derivative bottle in a refrigerator below-10 ℃ for cooling for 10min to 15min, adding 0.5mL of saturated sodium chloride aqueous solution and 0.5g of sodium bicarbonate powder into the derivative bottle, swirling, adding 2.0g of anhydrous sodium sulfate into the derivative bottle, swirling and centrifuging, then completely taking the upper organic solution into a glass centrifuge tube, blowing nitrogen to the glass centrifuge tube at 40 ℃ for drying, adding 2.00mL of acetone into the glass centrifuge tube for constant volume, swirling, absorbing the upper organic solution, filtering, and then performing analysis and test by using a gas chromatography according to the following conditions:
a) a chromatographic column: HP-5 capillary column, 30m × 0.32mm, 0.25 μm film thickness; constant flow mode, column flow rate: 2.00 mL/min;
b) sample inlet temperature: 250 ℃; and (3) sample introduction mode: no shunt sampling; sample introduction amount: 2 mu L of the solution; tail gas blowing flow: 60 mL/min;
c) temperature rising procedure: keeping at 60 deg.C for 1min, heating to 150 deg.C at 15 deg.C/min, keeping for 1min, heating to 250 deg.C at 10 deg.C/min, keeping for 1min, and then operating at 300 deg.C for 3 min;
d) a detector: microelectronic capture detector, temperature: 325 ℃;
e) carrier gas: high-purity nitrogen with the purity more than or equal to 99.999 percent.
2. The gas chromatography method for determining the residues of eight phenoxy carboxylic acid herbicides in corn as claimed in claim 1, wherein the alkaline 10% acetone aqueous solution in step (1) is adjusted to pH 9.0 by 0.01mol/L sodium hydroxide aqueous solution, the high speed homogenizing rate is 15000rpm, the time is 1min, and the shaking time is 15 min.
3. The gas chromatography method for determining the residues of eight phenoxy carboxylic acid herbicides in corn as claimed in claim 1, wherein the hydrochloric acid solution in step (2) is prepared from concentrated hydrochloric acid and water according to a volume ratio of 1:1, and the dosage is 5.00 mL.
4. The gas chromatography method for determining the residues of eight phenoxy carboxylic acid herbicides in corn of claim 1, wherein the anhydrous sodium sulfate added in step (3) is 2.0g, and the organic extraction solvent is 5.00mL ethyl acetate.
5. The gas chromatography method for determining the residues of eight phenoxy carboxylic acid herbicides in corn as claimed in claim 1, wherein the filtration membrane in step (4) is an organic phase filtration membrane with a pore size of 0.22 μm.
6. The gas chromatography method for determining the residues of eight phenoxy carboxylic acid herbicides in corn of claim 1, wherein the vortexing is performed for 1min and the centrifugation is performed at 4500rpm for 3 min.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101798283A (en) * | 2010-03-15 | 2010-08-11 | 北京市农林科学院 | Derivatization method in carboxylic acid compound detection process by gas chromatogram |
| EP2376221A1 (en) * | 2008-12-09 | 2011-10-19 | CRC Care Pty Ltd | Modified clay sorbents |
| CN103226138A (en) * | 2013-01-24 | 2013-07-31 | 江苏省环境监测中心 | Method for fast detecting phenoxy carboxylic acid herbicide in water |
| KR20140036734A (en) * | 2012-09-18 | 2014-03-26 | 한국과학기술연구원 | Method for analyzing acidic herbicides using isotope dilution and gas chromatography/tandem mass spectrometry |
| CN106018634A (en) * | 2016-07-17 | 2016-10-12 | 福清出入境检验检疫局综合技术服务中心 | Method for adsorbing and desorbing six phenoxy carboxylic acid herbicides in water with nitrate-type layered double hydroxides (LDHS) adsorbent |
| CN108181394A (en) * | 2017-12-27 | 2018-06-19 | 国家烟草质量监督检验中心 | The method that a kind of extraction-purification Synchronos method measures three kinds of phenoxy carboxylic acid persticide residues in tobacco |
-
2018
- 2018-11-25 CN CN201811412354.1A patent/CN109283276B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2376221A1 (en) * | 2008-12-09 | 2011-10-19 | CRC Care Pty Ltd | Modified clay sorbents |
| CN101798283A (en) * | 2010-03-15 | 2010-08-11 | 北京市农林科学院 | Derivatization method in carboxylic acid compound detection process by gas chromatogram |
| KR20140036734A (en) * | 2012-09-18 | 2014-03-26 | 한국과학기술연구원 | Method for analyzing acidic herbicides using isotope dilution and gas chromatography/tandem mass spectrometry |
| CN103226138A (en) * | 2013-01-24 | 2013-07-31 | 江苏省环境监测中心 | Method for fast detecting phenoxy carboxylic acid herbicide in water |
| CN106018634A (en) * | 2016-07-17 | 2016-10-12 | 福清出入境检验检疫局综合技术服务中心 | Method for adsorbing and desorbing six phenoxy carboxylic acid herbicides in water with nitrate-type layered double hydroxides (LDHS) adsorbent |
| CN108181394A (en) * | 2017-12-27 | 2018-06-19 | 国家烟草质量监督检验中心 | The method that a kind of extraction-purification Synchronos method measures three kinds of phenoxy carboxylic acid persticide residues in tobacco |
Non-Patent Citations (4)
| Title |
|---|
| Experimental design for the study of two derivatization procedures for simultaneous GC analysis of acidic herbicides and water chlorination by-products;Ce´cile Boucharat et al.;《Talanta》;19981026;第47卷(第2期);311-323 * |
| Simultaneous Determination of 13 Phenoxy Acid Herbicide Residues in Soybean by GC-ECD;Kuang Hua et al.;《Analytical Letters》;20070202;第39卷(第13期);2617-2627 * |
| 对甲苯磺酸根插层Mg3Al-LDHS的制备及其对水中六种苯氧羧酸类除草剂的吸附性能;丁立平 等;《化学工程师》;20180625(第6期);7-11 * |
| 气相色谱法同时测定大豆中13种苯氧羧酸类除草剂的残留量;匡华 等;《中国食品卫生杂志》;20061130(第6期);503-508 * |
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