CN112946141A - Method for detecting phosmet in soil - Google Patents

Abstract

The invention discloses a method for detecting phosmet in soil, relates to the field of methods for detecting pesticide residues in soil in the field of environmental detection, and aims to solve the problem that no mature detection method or standard is available in the industry for detecting phosmet in the environment at present. The method comprises the following steps: step 1: coarse screening to remove large-particle-size interferents, such as: weighing two parts of a soil sample, namely a stone and a dead leaf, wherein the parts are marked as A part and B part respectively, and each part is 10 g; step 2: adding 20g of anhydrous sodium sulfate into the part A for dehydration, and grinding and homogenizing the part A into a quicksand shape in a grinding bowl; b parts reference HJ 613 their dry matter content; and step 3: transferring the A parts of soil sample to a conical flask, adding 50ml of acetone, placing an ultrasonic probe below the liquid level, and ultrasonically extracting for 3 times, 5min each time; and 4, step 4: transferring the obtained supernatant to a nitrogen blowing instrument, and performing nitrogen blowing concentration to 1 ml; and 5: and (4) carrying out quantitative analysis on the concentrated solution in the fourth step by an external standard method by using a gas chromatograph, and carrying out gradient dilution by using acetone.

Description

Method for detecting phosmet in soil

Technical Field

The invention relates to the field of detection methods of pesticide residues in soil in the field of environmental detection, in particular to a detection method of phosmet in soil.

Background

Phosmet is a broad-spectrum acaricide and insecticide, and is an organophosphorus pesticide with moderate toxicity. At present, the method is mainly applied to fruit trees, fields and ornamental trees.

The phosmet can enter the environment in the normal use process, has obvious influence on bees and aquatic organisms, and is shown as influence on the aspect of a nervous system, such as respiratory depression and the like.

With the intensive research on the substance, the detection means of the content of the phosmet in the food is relatively mature, and is mainly reflected in the release of related research documents and the emergence of related national standards.

Recent scientific studies have shown that phosmet may have greater environmental toxicity. However, in the field of environment, research on the substance is not sufficient, and particularly, no mature detection method or standard is available in the industry to detect the phosmet in the environment, so that a detection method for the phosmet in the soil is urgently needed in the market to solve the problems.

Disclosure of Invention

The invention aims to provide a method for detecting phosmet in soil, which aims to solve the problem that no mature detection method or standard exists in the industry at present to detect the phosmet in the environment, wherein the problem is provided in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: a method for detecting phosmet in soil comprises the following steps:

step 1: coarse screening to remove large-particle-size interferents, such as: weighing two parts of a soil sample, namely a stone and a dead leaf, wherein the parts are marked as A part and B part respectively, and each part is 10 g;

step 2: adding 20g of anhydrous sodium sulfate into the part A for dehydration, and grinding and homogenizing the part A into a quicksand shape in a grinding bowl; b parts reference HJ 613 their dry matter content;

and step 3: transferring the soil sample A in the step two to a conical flask, adding 50ml of acetone, placing an ultrasonic probe below the liquid level, and ultrasonically extracting for 3 times, wherein each time lasts for 5 min;

and 4, step 4: transferring the supernatant obtained in the step three to a nitrogen blowing instrument, and carrying out nitrogen blowing concentration to 1 ml;

and 5: performing external standard quantitative analysis on the concentrated solution in the fourth step by using a gas chromatograph, and performing gradient dilution by using acetone, wherein the concentration points of a standard curve are respectively as follows: 0.5. mu.g/ml, 1. mu.g/ml, 2. mu.g/ml, 5. mu.g/ml, 10. mu.g/ml.

Preferably, the dehydrating agent used in the step 2 is anhydrous sodium sulfate.

Preferably, the A soil samples in the step 2 are in a homogeneous quicksand-shaped final dehydration treatment state.

Preferably, the reference condition of the ultrasonic extraction apparatus in step 3 is ultrasonic extraction for 3 times, each time for 5 min.

Preferably, in the step 5, a gas chromatograph with an FPD detector is selected, the detection wavelength is 526nm, and the chromatographic column: 30m × 0.32mm × 0.25 μm, 14% cyanopropyl-86% dimethylpolysiloxane or equivalent chromatography column, injection port temperature: 260 ℃, column temperature: maintaining at 260 ℃ for 15min, and controlling the temperature of a gasification chamber: 270 ℃, detection chamber temperature: 270 ℃, carrier gas: nitrogen gas 1.2ml/min, no split injection.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention provides a complete detection method of phosmet in soil for the first time in the industry;

2. by selecting a proper extracting agent and an extracting method, the pretreatment efficiency is fully guaranteed;

3. the method can accurately quantify the phosmet in the soil through chromatography.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

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

Example 1: a method for detecting phosmet in soil comprises the following steps:

step 1: coarse screening to remove large-particle-size interferents, such as: weighing two parts of a soil sample, namely a stone and a dead leaf, wherein the parts are marked as A part and B part respectively, and each part is 10 g;

step 2: adding 20g of anhydrous sodium sulfate into the part A for dehydration, and grinding and homogenizing the part A into a quicksand shape in a grinding bowl; b parts reference HJ 613 their dry matter content;

and step 3: transferring the soil sample A in the step two to a conical flask, adding 50ml of acetone, placing an ultrasonic probe below the liquid level, and ultrasonically extracting for 3 times, wherein each time lasts for 5 min;

and 4, step 4: transferring the supernatant obtained in the step three to a nitrogen blowing instrument, and carrying out nitrogen blowing concentration to 1 ml;

and 5: performing external standard quantitative analysis on the concentrated solution in the fourth step by using a gas chromatograph, and performing gradient dilution by using acetone, wherein the concentration points of a standard curve are respectively as follows: 0.5. mu.g/ml, 1. mu.g/ml, 2. mu.g/ml, 5. mu.g/ml, 10. mu.g/ml.

Further, the dehydrating agent used in step 2 is anhydrous sodium sulfate.

Further, the final dehydration treatment state of the soil sample A in the step 2 is a homogeneous quicksand shape.

Further, the reference condition of the ultrasonic extraction instrument in the step 3 is ultrasonic extraction for 3 times, and each time is 5 min.

Further, in step 5, a gas chromatograph with an FPD detector is selected, the detection wavelength is 526nm, and a chromatographic column: 30m × 0.32mm × 0.25 μm, 14% cyanopropyl-86% dimethylpolysiloxane or equivalent chromatography column, injection port temperature: 260 ℃, column temperature: maintaining at 260 ℃ for 15min, and controlling the temperature of a gasification chamber: 270 ℃, detection chamber temperature: 270 ℃, carrier gas: nitrogen gas 1.2ml/min, no split injection.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (5)

1. A method for detecting phosmet in soil is characterized by comprising the following steps:

step 1: coarse screening to remove large-particle-size interferents, such as: weighing two parts of a soil sample, namely a stone and a dead leaf, wherein the parts are marked as A part and B part respectively, and each part is 10 g;

step 2: adding 20g of anhydrous sodium sulfate into the part A for dehydration, and grinding and homogenizing the part A into a quicksand shape in a grinding bowl; b parts reference HJ 613 their dry matter content;

and step 3: transferring the soil sample A in the step two to a conical flask, adding 50ml of acetone, placing an ultrasonic probe below the liquid level, and ultrasonically extracting for 3 times, wherein each time lasts for 5 min;

and 4, step 4: transferring the supernatant obtained in the step three to a nitrogen blowing instrument, and carrying out nitrogen blowing concentration to 1 ml;

and 5: performing external standard quantitative analysis on the concentrated solution in the fourth step by using a gas chromatograph, and performing gradient dilution by using acetone, wherein the concentration points of a standard curve are respectively as follows: 0.5. mu.g/ml, 1. mu.g/ml, 2. mu.g/ml, 5. mu.g/ml, 10. mu.g/ml.

2. The method for detecting phosmet in soil according to claim 1, wherein the dehydrating agent used in the step 2 is anhydrous sodium sulfate.

3. The method for detecting phosmet in soil according to claim 1, wherein the final dehydration treatment state of the A parts of soil sample in the step 2 is a homogeneous flowing sand shape.

4. The method for detecting phosmet in soil according to claim 1, wherein the instrument reference condition for ultrasonic extraction in step 3 is ultrasonic extraction for 3 times, each time for 5 min.

5. The method for detecting phosmet in soil according to claim 1, wherein a gas chromatograph with an FPD detector is selected in the step 5, the detection wavelength is 526nm, and a chromatographic column: 30m × 0.32mm × 0.25 μm, 14% cyanopropyl-86% dimethylpolysiloxane or equivalent chromatography column, injection port temperature: 260 ℃, column temperature: maintaining at 260 ℃ for 15min, and controlling the temperature of a gasification chamber: 270 ℃, detection chamber temperature: 270 ℃, carrier gas: nitrogen gas 1.2ml/min, no split injection.

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