This standard specifies the rapid detection method for the residues of organophosphorus such as methamidophos and carbamate pesticides such as chlorpyrifos in vegetables. This standard is applicable to the rapid detection of pesticide residues such as methamidophos, omethoate, parathion, phorate, monocrotophos, fenthion, methidathion, dichlorvos, chlorpyrifos, aldicarb, methomyl, pirimicarb, carbosulfan, methylsulfuron, benfuracarb, methimide, propoxur, and isoprocarb in leafy vegetables (except leeks), fruit vegetables, legume vegetables, melon vegetables, and root vegetables (except carrots and water chestnuts). NY/T 448-2001 Rapid detection method for the residues of organophosphorus and carbamate pesticides on vegetables NY/T448-2001 Standard download decompression password: www.bzxz.net
This standard specifies the rapid detection method for the residues of organophosphorus such as methamidophos and carbamate pesticides such as chlorpyrifos in vegetables. This standard is applicable to the rapid detection of pesticide residues such as methyl parathion, oxychlorpyrifos, parathion, phorate, monocrotophos, fenthion, methidathion, dichlorvos, chlorpyrifos, aldicarb, methomyl, pirimicarb, carbofuran, chlorpyrifos, bensulfuron, chlorpyrifos, propachlor, and isoprocarb in leafy vegetables (except leeks), fruiting vegetables, bean vegetables, melon vegetables, and root vegetables (except carrots, water chestnuts, etc.).

NY/T448--2001
This method can rapidly detect organophosphate and carbamate pesticide residues in vegetables. This standard is proposed by the Ministry of Agriculture of the People's Republic of China. This standard is drafted by the Pesticide Control Institute of the Ministry of Agriculture. The main drafters of this standard are Gao Xiaohui, Zhu Guangyan, Tao Chuanjiang, Qin Dongmei, Gong Yong, Liu Guangxue, and He Yibing. This standard is interpreted by the Pesticide Control Institute of the Ministry of Agriculture. 223
1 Scope
Agricultural Industry Standards of the People's Republic of China
Rapid bioassay of organophosphate and carbamate pesticide residues in vegetablesNY/T448-2001
This standard specifies the rapid detection method of organophosphate and other organophosphates and carbamate pesticide residues such as carbofuran in vegetables. This standard is applicable to the rapid detection of pesticide residues such as methamidophos, omethoate, parathion, phorate, monocrotophos, fenthion, methidathion, dichlorvos, carbofuran, aldicarb, methomyl, pirimicarb, carbosulfan, carbaryl, benfuracarb, mefenacet, propoxur, and isoprocarb in leafy vegetables (except leeks), fruit vegetables, bean vegetables, mefenacet, and mefenacet. 2 Principle
Organophosphorus and carbamate pesticides can inhibit the activity of acetylcholinesterase in the central and peripheral nervous systems of insects, causing the accumulation of acetylcholine, a neurotransmitter, affecting normal conduction and causing insect poisoning and death. Based on this insect toxicology principle, it is used in the detection of pesticide residues. After adding the reaction reagent, the change of absorbance over time is measured by a spectrophotometer, and the inhibition rate is calculated to determine the residual toxicity of organophosphorus or carbamate pesticides in vegetables. That is: acetylcholinesterase + organophosphorus or carbamate pesticides → enzyme activity is inhibited → activity is inhibited → sample contains organophosphorus or carbamate pesticides acetylcholinesterase + sample extract
→ activity is normal → sample does not contain organophosphorus or carbamate pesticides For example, acetylthiocholine (AsCh) is used as a substrate. Under the action of acetylcholinesterase (AChE), acetylthiocholine (AsCh) is hydrolyzed into thiocholine and acetic acid. Thiocholine and dithiobis-p-nitrobenzoic acid (DTNB) produce a color reaction, making the reaction solution yellow. There is a maximum absorption peak at 410nm in the spectrophotometer. The degree of enzyme activity inhibition can be measured by a spectrophotometer (expressed as inhibition rate). 3 Reagents
3.7 pH 8 phosphate buffer.
3.2 Butyrylcholinesterase: Dissolve with buffer as required according to the enzyme activity, and the △A value is controlled between 0.4 and 0.8. 3.3 Substrate: s-butyrylthiocholine iodide (BTCI), dissolved in buffer. 3.4 Color developer: 5,5-dithiobis (nitrobenzoic acid, DTNBJ, dissolved in buffer. 4 Instruments
4.1 Special rapid measuring instrument with a wavelength of 410nm±3nm, or visible light spectrophotometer. Approved by the Ministry of Agriculture of the People's Republic of China on June 1, 2001. 224
Implementation on October 1, 2001
4.2 Electronic balance (accuracy 0.1g).
4.3 Micro sample mixer.
Desktop incubator.
NY/T 448 -- 2001
Adjustable pipette: (10~100μL, 1~5mL). Stainless steel sampler (inner diameter 2cm).
Matching glass instruments and other accessories.
5.1 Sampling
Use a stainless steel tube sampler to take samples from leaves of different plants (at least 8 to 10 leaves); for fruits and vegetables, take samples from 1 to 1.5cm from the skin to the flesh. www.bzxz.net
5.2 Testing process
Take 2g of chopped sample (non-leafy vegetables take 4g), put it into the extraction bottle, add 20mL buffer, shake for 1~2min, pour out the extract, let it stand for 3~5min, add 50uL enzyme, 3mL sample extract, 50μL color developer into the small test tube, place it at 37~38℃ for 30min, then add 50μL substrate, pour it into the colorimetric cup, and measure it with the instrument. 5.3 Calculation of test results
The test results are calculated according to formula (1):
Inhibition rate (%) =
AA AAs
Where: AA. —The difference between the absorbance of the control group 3 minutes later and 3 minutes earlier; AA—The difference between the absorbance of a sample 3 minutes later and 3 minutes earlier. (1)
When the inhibition rate is ≥70%, the vegetables contain some organophosphorus or carbamate pesticide residues. At this time, the sample should be tested more than twice, and the reproducibility of several repeated tests should be above 80%. 6 Minimum detection concentration
The minimum detection concentration of this method is shown in Table 1.
Chinese name of pesticide
Methylamidophos
Omethoate
Parathion
Phorate
Long-lasting phosphorus
Chromated phosphorus
Methiothion
Dichlorvos
Carbofuran
Aldicarb
Methamidocarb
Anisicarb
English Common Name
methamidophos
omethoate
parathion
phorate
monocroto-phos
fenthion
methidathion
dichlorovos
carbofuran
aldicarb
methomyl
pirimicarb
Minimum Detectable Concentration (Solution)
0, 3～0. 7
0.3～0.7
Low detection concentration (vegetables)
Chinese name of pesticide
Butylsulfuron
Benfuracarb
Methocarb
Propoxur
Isoprocarb
English common name
carbosulfan
carbaryl
benfuracarb|| tt||propoxur
isoprocarb
3—2001
NY/T448
Table 1 (end)
Minimum detection concentration (solution)
Minimum detection concentration (vegetables)
Butyrylcholinesterase is not very sensitive to pesticides such as methyl parathion, dimethoate, chlorpyrifos, and diazinon, and the detection concentrations are all above 10 mg/kg. 226
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