A detection kit and method for dicofol

Abstract

The invention discloses a detection kit and a method for dicofol. The principle that the activity of lipase can be increased along with the increase of the concentration of the dicofol is utilized; whether the dicofol exists or not is detected by detecting the lipase activity, so that the dosage of an organic solvent is reduced, the detection limit is improved, strong acid and an organic solvent with foul smell are prevented from being used, the operation process is simplified, the detection efficiency is improved, and the method is suitable for field operation and rapid detection.

Description

technical field

[0001] The invention relates to the field of organic compound detection, in particular to a kit and method for detecting dicofol. Background technique

[0002] Dicofol is a low toxicity and high efficiency organochlorine acaricide, insoluble in water, soluble in various organic solvents, and has low toxicity to humans and animals. This kind of pesticide is a special pesticide for cicada mite pests. It has a good control effect on adults, nymphs and eggs. In addition, its structure is stable, its decomposition is slow, and its residual effect is long. Therefore, it was popularized and applied in my country's tea production in the late last century. . However, the production of most dicofol products uses DDT as the main intermediate, and the residual refining process is not up to standard, resulting in excessive DDT content in a large number of finished products. Therefore, when dicofol is sprayed, a certain amount of DDT is also mixed, so in the tea gardens a...

Examples

Embodiment 1

[0034] 1) Weigh 3g of crushed tea leaves into a centrifuge tube, add 10mL of n-hexane, cover tightly, shake up and down 50 times, and let stand;

[0035] 2) Pour the extract into another centrifuge tube, add 0.5g of silicon-magnesium-type adsorbent, shake it 50 times, and let it stand for stratification;

[0036] 3) Take the supernatant and dry it, add 2mL pH8.0 buffer to redissolve, then add 0.5mL lipase, and pre-react for 5min;

[0037] 4) Add 0.5 mL of 0.15 mg / L p-nitrophenol ester solution, react for 10 min, and detect the absorbance at a wavelength of 405 nm.

Embodiment 2

[0039] 1) Weigh 5g of crushed vegetables into a centrifuge tube, add 8mL of acetone, cover tightly, shake up and down 50 times, and let stand;

[0040] 2) Pour the extract into another centrifuge tube, add 1g of silica gel, shake 50 times, and let stand to separate layers;

[0041] 3) Take the supernatant and dry it, add 1mL pH8.5 buffer to redissolve, then add 0.5mL lipase, and pre-react for 5min;

[0042] 4) Add 1.5 mL of 0.05 mg / L p-nitrophenol ester solution, react for 10 min, and detect the absorbance at a wavelength of 405 nm.

Embodiment 3

[0044] 1) Weigh 10 g of crushed fruit into a centrifuge tube, add 5 mL of ethyl acetate, cover tightly, shake up and down 50 times, and let stand;

[0045] 2) Pour the extract into another centrifuge tube, add 0.2g of neutral alumina, shake 50 times, and let stand to separate layers;

[0046] 3) Take the supernatant and dry it, add 4mL pH7.5 buffer solution to redissolve, then add lipase and nitrophenol ester solution, and detect the absorbance value at a wavelength of 405nm after reaction.

[0047] 1. Detection limit test:

[0048] Get 6 centrifuge tubes, add 5g of pulverized vegetable samples to each, add dicofol pesticide standard substance, the concentration of adding standard is respectively 0, 0.1, 0.2, 0.3, 0.4, 0.5mg / kg, according to the pretreatment method of embodiment 2 of the present invention and Detection method, the reaction solution detects the absorbance value at a wavelength of 405nm, and the following table is obtained:

[0049] Dicofol (mg / kg) 0...

technical field

[0001] The invention relates to the field of organic compound detection, in particular to a kit and method for detecting dicofol. Background technique

[0002] Dicofol is a low toxicity and high efficiency organochlorine acaricide, insoluble in water, soluble in various organic solvents, and has low toxicity to humans and animals. This kind of pesticide is a special pesticide for cicada mite pests. It has a good control effect on adults, nymphs and eggs. In addition, its structure is stable, its decomposition is slow, and its residual effect is long. Therefore, it was popularized and applied in my country's tea production in the late last century. . However, the production of most dicofol products uses DDT as the main intermediate, and the residual refining process is not up to standard, resulting in excessive DDT content in a large number of finished products. Therefore, when dicofol is sprayed, a certain amount of DDT is also mixed, so in the tea gardens a...

Examples

Embodiment 1

[0034] 1) Weigh 3g of crushed tea leaves into a centrifuge tube, add 10mL of n-hexane, cover tightly, shake up and down 50 times, and let stand;

[0035] 2) Pour the extract into another centrifuge tube, add 0.5g of silicon-magnesium-type adsorbent, shake it 50 times, and let it stand for stratification;

[0036] 3) Take the supernatant and dry it, add 2mL pH8.0 buffer to redissolve, then add 0.5mL lipase, and pre-react for 5min;

[0037] 4) Add 0.5 mL of 0.15 mg / L p-nitrophenol ester solution, react for 10 min, and detect the absorbance at a wavelength of 405 nm.

Embodiment 2

[0039] 1) Weigh 5g of crushed vegetables into a centrifuge tube, add 8mL of acetone, cover tightly, shake up and down 50 times, and let stand;

[0040] 2) Pour the extract into another centrifuge tube, add 1g of silica gel, shake 50 times, and let stand to separate layers;

[0041] 3) Take the supernatant and dry it, add 1mL pH8.5 buffer to redissolve, then add 0.5mL lipase, and pre-react for 5min;

[0042] 4) Add 1.5 mL of 0.05 mg / L p-nitrophenol ester solution, react for 10 min, and detect the absorbance at a wavelength of 405 nm.

Embodiment 3

[0044] 1) Weigh 10 g of crushed fruit into a centrifuge tube, add 5 mL of ethyl acetate, cover tightly, shake up and down 50 times, and let stand;

[0045] 2) Pour the extract into another centrifuge tube, add 0.2g of neutral alumina, shake 50 times, and let stand to separate layers;

[0046] 3) Take the supernatant and dry it, add 4mL pH7.5 buffer solution to redissolve, then add lipase and nitrophenol ester solution, and detect the absorbance value at a wavelength of 405nm after reaction.

[0047] 1. Detection limit test:

[0048] Get 6 centrifuge tubes, add 5g of pulverized vegetable samples to each, add dicofol pesticide standard substance, the concentration of adding standard is respectively 0, 0.1, 0.2, 0.3, 0.4, 0.5mg / kg, according to the pretreatment method of embodiment 2 of the present invention and Detection method, the reaction solution detects the absorbance value at a wavelength of 405nm, and the following table is obtained:

[0049] Dicofol (mg / kg) 0...