This standard specifies the method for determining the residues of fluazifop-butyl and fluazifop-butyl in plant-derived foods. This standard applies to sugar beets and soybeans harvested after the chemical herbicides fluazifop-butyl and fluazifop-butyl were sprayed once in sugar beet and soybean fields. This standard also applies to the determination of fluazifop-butyl acid. GB/T 5009.142-2003 Determination of fluazifop-butyl and fluazifop-butyl residues in plant-derived foods GB/T5009.142-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.142—2003
Replaces GB/T17328—1998bzxZ.net
Determination of fluazifop-butyl and its acidresidues in vegetable food
Promulgated on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on January 1, 2004
This standard replaces GB/T17328—1998 "Determination of fluazifop-butyl and its acidresidues in food". Compared with GB/T17328--1998, this standard has been modified as follows: GB/T5009.142-2003
The Chinese name of the standard has been modified, and the Chinese name of the standard has been changed to "Determination of fluazifop-butyl and fluazifop-butyl residues in plant-based foods";
Introduction has been added:
The structure of the original standard has been modified according to GB/T20001.4-2001 "Standard Preparation Rules Part 4: Chemical Analysis Methods".
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. The responsible drafting unit of this standard: Harbin Medical University. The main drafters of this standard are Cui Hongbin, Zhao Xiujuan, Chen Bingqing, Sun Zhiyong, and Wu Kun. The original standard was first issued in 1998, and this is the first revision. 215
GB/T5009.142—2003
Pyrifos-P-ethyl (Wenshade) and Pyrifos-P-ethyl (Wenshade) are highly effective and low-toxic chemical herbicides used for weeding in beet and soybean fields. my country stipulates that the maximum residue of pyrifos-P-ethyl and Pyrifos-P-ethyl in beets and soybeans is 0.5 mg/kg. This standard is a matching determination method.
Since pyrifos-P-ethyl and Pyrifos-P-ethyl will degrade into pyrifos acid in the environment or in plants after application, this standard also stipulates the determination method of pyrifos acid. 216
1 Scope
Determination of fluazifop-butyl and fluazifop-butyl-Phenyl residues in plant-derived foods
GB/T5009.142—2003
This standard specifies the method for determining the residues of fluazifop-butyl and fluazifop-butyl-Phenyl in plant-derived foods. This standard is applicable to sugar beets and soybeans harvested after the sugar beet and soybean fields have been sprayed with chemical herbicides fluazifop-butyl and fluazifop-butyl-Phenyl once.
This standard is also applicable to the determination of fluazifop-butyl acid. The detection limit of this method is 0.001ng, and the linear range is: 1.0×10-12g~4.0×10-1°g. 2 Principle
After the sample is extracted, purified, brominated and derivatized, it is quantitatively determined by gas chromatograph with Ni electron capture detector. 3 Reagents
Methanol: re-distilled and refined.
Acetonitrile.
Petroleum ether: re-distilled and refined (60℃~90℃). 3.3
Acetone: re-distilled and refined.
50g/L pentafluorobenzyl bromide.
Anhydrous sodium sulfate: analytical grade.
20g/L sodium sulfate solution.
3.920g/L sodium carbonate.
Soybean oil.
3.11 Fluoroli silica.
3.12 Fluazifopbutyl standard solution: accurately weigh 100.0mg of fluazifopbutyl refined product, dissolve it in petroleum ether, transfer it to a 100mL volumetric flask, add petroleum ether to the mark, and mix well. Each milliliter of this solution is equivalent to 1mg of fluazifopbutyl. 3.13 Fluazifop-p-butyl working solution: Take 1.0 mL of fluazifop-p-butyl standard solution, place it in a 1000 mL volumetric flask, and dilute it to the mark with petroleum ether. This solution is equivalent to 1.0 g of fluazifop-p-butyl per milliliter. 3.14 Fluazifop-p-butyl standard solution: Accurately weigh 100.0 mg of fluazifop-p-butyl product, dissolve it in petroleum ether, transfer it to a 100 mL volumetric flask, add petroleum ether to the mark, and mix well. This solution is equivalent to 1 mg of fluazifop-p-butyl per milliliter. 3.15 Fluazifop-p-butyl working solution: Take 1.0 mL of fluazifop-p-butyl standard solution, place it in a 1000 mL volumetric flask, and dilute it to the mark with petroleum ether. This solution is equivalent to 1.0 μg of fluazifop-p-butyl per milliliter. 4 Instruments
4.1 Gas chromatograph (electron capture detector). 4.2 Rotary evaporator.
4.3 Tissue crusher.
4.4 Constant temperature water bath.
GB/T5009.142—2003
4.5 Glass chromatography column.
4.65μ. Micro-injector.
4.7 Electric oscillator.
5 Analysis steps
5.1 Pretreatment of fluazifop-butyl: Bromination, derivatization and purification 5.1.1 Treatment of beet sample
Weigh 20g of beet sample and put it into a pulper. Add 200mL of methanol to make a pulp. Put it into a conical flask and seal it overnight. Filter and collect the filtrate.
5.1.2 Treatment of soybean sample
Crush soybean and pass it through a 40-mesh sieve. Weigh 10g of soybean and add 20mL of water and 80mL of acetonitrile. Use an electric oscillator to lift it for 30 minutes, filter and collect the filtrate.
5.1.3 Extraction, bromination derivatization, purification
Put the filtrate in a separatory funnel, add 150mL 20g/L sodium sulfate solution, 80ml. petroleum ether for extraction, discard the aqueous phase after stratification, and extract once with 20g/L sodium sulfate (Na2SO.). After the organic phase is dehydrated with anhydrous sodium sulfate, it is concentrated to near dryness at 40℃ using a rotary evaporator. Add 1mL 20mg/mlL soybean oil acetone solution to evenly distribute the inner wall of the bottle, and remove the acetone. Add 0.4ml of liquid and quickly seal the bromination, then evaporate to remove the residual bromine, add 20mL petroleum ether, wash to remove the residual bromine, and concentrate to a residue. Wash the residue with acetone and petroleum ether and transfer it to a separatory funnel. Then add 150mL 20g/L sodium sulfate solution and 150mL 20g/L sodium carbonate solution to wash. Discard the aqueous phase. Dehydrate the organic phase with anhydrous sodium sulfate and transfer it to a rotary evaporator to evaporate the petroleum ether. Dissolve the residue with 30mL ethyl ether + petroleum ether (15 + 85), pass through a fluorosilica column (activated at 650℃ for 3h, 130℃ overnight), and elute with 120mL ethyl ether + petroleum ether (15 + 85). Collect the eluent, concentrate it to dryness, make up to volume with petroleum ether, and measure. 5.2 Pretreatment, extraction, derivatization and purification of fluazifop-butyl acid 5.2.1 Treatment of beet sample
Weigh 20g beet sample, chop it, put it into a homogenizer, add 100mL acetone and 100mL water to make a homogenate, then add 6mL 6mol/L hydrochloric acid solution and seal it overnight, filter and collect the filtrate. Add 120mL dichloromethane, 150mL 20g/L sodium sulfate solution and 3mL 6mol/L hydrochloric acid solution to the filtrate for extraction. After layering, extract it with 80mL dichloromethane for 3 times, combine the dichloromethane solution, dehydrate it with anhydrous sodium sulfate, and concentrate it to dryness at 40℃. 5.2.2 Treatment and extraction of soybean sample
Crush soybean, pass it through a 40-mesh sieve, weigh 10g, add 97mL acetone and 3mL 6mol/L hydrochloric acid solution, soak the sample overnight, shake and extract for 30min, and place the filtrate in a rotary evaporator to concentrate it to dryness. Dissolve the residue with 120ml. dichloromethane and transfer it to a separatory funnel. Extract with 150mL20g/L sodium sulfate and 3mL6mol/L hydrochloric acid solution, discard the aqueous phase, dehydrate the organic phase with anhydrous sodium sulfate, and concentrate to dryness at 40℃.
5.2.3 Derivatization, purification, and volume adjustment
Add 5mL50g/L pentafluorobenzyl bromide and 1mL pyridine, seal and perform fluorinated esterification in a water bath at 80℃, react for 30min, take out, wash with 80mL petroleum ether, and transfer to a separatory funnel. Add 80mL20g/L sodium sulfate solution to extract, discard the aqueous phase, extract with 80mL20g/L sodium sulfate, discard the aqueous phase, extract with 50mL0.5mol/L hydrochloric acid solution, discard the aqueous phase, dehydrate the organic phase with anhydrous sodium sulfate, and concentrate to dryness at 40℃. Dissolve the residue with 30 mL of ether + petroleum ether (15 + 85), pass through a fluorosilica column (activated at 650°C for 3 h, 130°C overnight), elute with 120 mL of ether + petroleum ether (15 + 85), collect the eluate, concentrate to dryness, and make up to volume with petroleum ether for determination.
5.3 Determination
5.3.1 Gas chromatography (reference) conditions
Chromosorb WHP (100 mesh ~ 120 days) stationary phase
Detection temperature
Nitrogen (N) flow rate
Sensitivity
Injection volume
5.3.2 Gas chromatography analysis
3% E-60
245℃
295℃
60.0mL/min
2.5mm/min
GB/T5009.142—2003
Prepare standard solutions of different concentrations of fluazifop-butyl and fluazifop-butyl acid series. The concentration of the standard solution is 1ug/mL. Pipette 1μL, 2μL3μL, 4μL, and 5μL into the gas chromatograph respectively to draw the standard curve. At the same time, take 1μL of the sample solution and inject it into the gas chromatograph. The corresponding content is found from the measured peak area of ​​the standard curve. 6 Result calculation
Calculate according to the following formula:
Wherein:
AX1000
X—the content of fluazifop-butyl (fine fluazifop-butyl) in the sample, in milligrams per kilogram (mg/kg), A—the amount of fluazifop-butyl (fine fluazifop-butyl) in the injection volume, in nanograms (ng); m—the mass of the sample equivalent to the injection volume (mL), in grams (g). The calculation result retains two significant figures.
7 Precision
The absolute difference between two independent measurement results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 219
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