GB/T 5009.143-2003 Determination of amitraz residues in vegetables, fruits and edible oils

This standard specifies the determination method of amitraz residues in vegetables, fruits and edible oils. This standard is applicable to the determination of amitraz residues (and metabolites) in vegetables, fruits and edible oils. The detection limit of this method is 0.02mg/kg; linear range: 0.01ng～1.0ng. GB/T 5009.143-2003 Determination of amitraz residues in vegetables, fruits and edible oils GB/T5009.143-2003 Standard download decompression password: www.bzxz.net

JCS67.040
Baojia Standard of the People's Republic of China
GB/T 5009.143—2003
GB/T17329—199S
Determination of armilrax residues in vegetables, fruits and edible oils invegctables,fruitsedihlenj
2003-08-11 Issued
Ministry of Health of the People's Republic of China
National Standardization Administration of China
2004-01-01 Implementation
This standard replaces GR/T17323-1998 Determination of dimethoate residues in foods 3 This standard is similar to GB/T17329--1998. The main changes are as follows: GB/T500a.143-2003
“…” The Chinese name of the standard is revised. The Chinese name of the standard is changed to, fruit , Determination of the residual content of amitraz in edible oils - prepared according to GB/T 20101.4-2001≤ standard Part 1: Chemical analysis methods 3 The structure of the original standard has been modified
This standard was proposed by the Ministry of the People's Republic of China and the units responsible for the drafting of this standard are Donghua Normal University Analysis Center, Zhejiang Provincial Import and Export Commodity Inspection Bureau, Ministry of Health Food Hygiene Inspection Institute, and Baimin University of Science and Technology.
The main drafters of this standard: Wang Yuanhong, Rong Hui, Zhang Ying, Hu Xiuli, Guo Yixing The original standard was first released on April 20, 1995. This is the first revision, 22
GB/T 5009.143—2003
Mirraz, chemical name N-methyl-bis-(2,4-dimethylaminomethylamine. Trade name Mia, is a medium-toxic pesticide, a kind of miticide, used to treat pest mites on fruit trees, vegetables and other crops, and can also be used to control cattle, sheep and other crops. my country stipulates that the limit of mirraz in various foods is: 0.5mg/lg for fruit vegetables, 0.5mg/kg for fruit fruits, 2.0.5rmg/kg for raw cuttings. Cotton stalk oil =%0.0 5mg/kg, This standard provides a method for detecting the residue of dimethoate in vegetables, fruits and edible oils. 322
1 Scope
Determination of the residue of dimethoate in vegetables, fruits and edible oils
This standard specifies the determination method of dimethoate residue in vegetables, fruits and edible oils. This standard is applicable to the determination of dimethoate (and metabolites) residues in dried fruits and edible oils. The detection limit of this method is 0.02mg/kg. Linear range: 0,Cng～1.0 ton. 2 Principle
GB/T 5009.143—2003
The dimethylformamide (and metabolites) in the test rod are hydrolyzed to 2+4·trimethylolamine, and n-hexane is taken, and acid and alkali are repeatedly purified by liquid-liquid distribution: 2,4-dimethylformamide is converted into 2.4-dimethylbenzene heptachlorobutyric acid membrane with heptafluorobutyric anhydride, and the determination is carried out by gas chromatography equipped with an electron capture detector, and the external standard method is used.
3 Reagents
3.1 Heptafluorobutyric acid is of high purity.
3.2 Heptafluorobutyric acid,
3.3 Hydrogen sulfide: 530℃ for 4h, put in a sealed container for use, 3. Magnetic separation and water.
3.5 Sodium hydroxide: 10mrl/ml and 1.0mnl/ml. Sodium hydroxide solution: 10mrl/ml and 1.0mnl/ml. 3. Salt solution: 1.1 mol/L and 2.0 mol/L hydrochloric acid aqueous solution. 3.7 2,1-dimethylbenzene (content, 8%) standard solution: Use n-hexane to prepare 2,4-dimethylbenzene standard to prepare a 1.4 mg/mL standard stock solution, and use n-hexane to prepare a standard working solution of appropriate concentration as needed. 3.8 Amitraz standard, purity 99%. 3.9 Amitraz standard solution: Accurately weigh an appropriate amount of amitraz standard and use n-hexane to prepare a standard stock solution of 1.090 mg/mL. Prepare a urine solution of appropriate concentration as needed: T. Preparation and installation 4.1 Gas chromatograph, equipped with detection equipment, 4.2 Tissue scanner.
4.3 Transfer tube: 5 ml,
4.4 Flow device.
4.5 Microinjection: 10L
4.6 Centrifuge tube (20 mL), microcentrifuge tube (2U mL), graduated fraction funnel (12 ml.).4.7 Constant temperature water bath,
5 Analysis steps
5.1 Sample preparation
5.1.1 Fruit, vegetable and algae food
Crush and mix 1.0kg of sample, divide it into quarters, weigh about 2.000g (accurate to 0.001g) of sample and put it into a 10mL flask GB/T5009.143-2003
. Add 5ml of acid (2.0mml/L) and mix it on a mixer, connect a flow device and reflux at 120℃ for 2 hours. After cooling to room temperature, transfer the mixture in the flask to a 20mL centrifuge tube and add 1ml, 1ml, and 1ml of water. Rinse the flask with distilled water and put it into a centrifuge. Mix well on a mixer, add 3 mL of sodium hydoxide (10 ol/L), drain and cool, and extract on a mixer three times with 3 mL of 3 mL of isocyanate: centrifuge at 3000 r/min for 2 min each time. Transfer the remaining hexane phase with a pointed tube into another 20 ml of a centrifuge, and extract on a mixer three times with 1 mL, 1 mL, and 1 L of isocyanate (0.1 mu/L). Centrifuge at 3000 r/min for 1 min each time. Add another 20ml of the phase and centrifuge it into a tube. Then wash the acid phase with 3rmL, 3ml, and 3mL of n-hexane on a mixer, centrifuge at 3000r/min for 2min each time. Remove the n-hexane phase: add 1ml of hydroxide solution (1.0mal/.). Add 2mL, 2mL, and 1mL of n-hexane on a mixer, extract water three times, centrifuge at 30k0r/min for 2min each time. ㎡I. Its ratio is 1:1, and the n-hexane concentration is Eml: the temperature of each temperature is less than 1Emin. 5.1.2 Edible oils
Weigh 20.0 (accurate to 0.1g) edible oil sample in a 1H1m conical flask, add 40mL 2.0mol/L hydrochloric acid and heat to 11, then transfer to a separating funnel, rinse the conical flask with a small amount of distilled water and put it into a separating funnel, add 20ml n-hexane, let it stand and separate, then discard the phase. Add 10mL 10.0mol/L sodium hydroxide to the phase, shake thoroughly, then use 30m.T..30mmJ. n-hexane to extract, add 10mL.10mL 1.0mol/L salt, discard the n-hexane phase. Add 15mL hexane to the acid phase, and neutralize the monobasic with 10.3ml/1.5% chlorine. Separate the alkali phase, and then use 19mL n-hexane to extract the water phase and combine the n-hexane phase, and dry it over anhydrous sodium sulfate. Then move to a 10-min colorimetric tube and fix with n-hexane to 5 m. 5.1.3 Blank test
Carry out the same procedure as in 5.1.1 or 5.1.2 except that no sample is added. 5.2 Derivatization
Add 10% of the above-mentioned anhydride to the alkane, add 1% of the anhydride, mix well, and dry in 50% warm water for 1 h. Cool to room temperature, add 3 mL of saturated sodium bicarbonate, add 1 mL of sodium hydroxide, and separate the organic phases. Dry with anhydrous sodium for determination. 3 Chromatographic strips
Chromatographic column: glass column (2m×mm inner diameter). Filling material is 5% SF-30 polyester in CForr: 50rlW (81℃~110℃); Chromatographic temperature: 135℃,
Inlet system: 250℃ bzxz.net
Detection group
Gas: chlorine (99.999%). 3mmL/in5.4 Determination
Take 5ml of standard working solution. According to the method of 3.2, the peak height of 2.4-dimethylamine is determined. Working solution: The response value of 2.4-dimethylamine in the standard working solution and the sample should be within the instrument measurement level of 0,1.2. The standard filter sample is injected. Under the above-mentioned color conditions, the retention time of 2,4-dimethoxybenzene is about 4.3min/min. The retention time of 2,4-dimethoxybenzene is calculated as follows:
In Chinese:
=hcYx:.21
: The retention time of 2,4-dimethoxybenzene in the sample, unit is milligram per dry gram (mg/kg): 4-1: The peak height of 2,4-dimethoxybenzene in the sample, unit is meter (m)c--the peak height of 2,4-dimethoxybenzene in the standard working concentration, unit is meter (m).The concentration of 4-dimethylbenzamine is expressed in micrograms per liter (g/mL) 224
The sample volume is expressed in micrograms per liter (mL); the sample is weighed in grams (R), 1.2-2,1-dimethylbenzamine is calculated as the correction factor for the use of micrograms, and the calculation result retains two significant digits.
7 Precision matching
CB/T5009.143-2003
The color chart of the two independent determination results obtained under the repeatability condition without leaving the arithmetic mean value
The color chart is shown in Figure 1.
The standard color chart of 12,4-trimethylbenzene heptachlorobutyric acid in the main measurement of the calibration 235
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.