GB/T 14929.2-1994 Determination of aldicarb residues in peanut kernels, cottonseed oil and peanut oil

This standard specifies the determination method of aldicarb residues. This standard is applicable to the determination of aldicarb and its metabolites residues in peanut kernels, cottonseed oil and peanut oil. GB/T 14929.2-1994 Determination method of aldicarb residues in peanut kernels, cottonseed oil and peanut oil GB/T14929.2-1994 Standard download decompression password: www.bzxz.net

GB/T14929.2—1994
National Standard of the People's Republic of China
Method for determination of aldicarb residues in peanut, cottonseed oil and peanut oilGB/T14929.2—1994
1 Subject content and scope of application
This standard specifies the method for determination of aldicarb residues. This standard is applicable to the determination of aldicarb and its metabolite residues in peanut kernels, cottonseed oil and peanut oil. The minimum detection limit of this method is 1.47ug, sampling 25g, fixed volume 1.0mL, injection 10uL, the minimum detection concentration is 0.0059mg/kg.
2 Principle
For samples containing aldicarb and its oxidized metabolites, aldicarb sulfoxide and aldicarb sulfone, strong oxidants, aldicarb sulfoxide and aldicarb sulfoxide are added during the extraction process to produce aldicarb with a higher response on the flame photometric detector of the gas chromatograph for determination. The total amount of aldicarb residue is expressed as the amount of aldicarb. 3 ReagentsbzxZ.net
3.1 Unless otherwise specified, only analytical reagents and distilled water or water of equivalent purity should be used. 3.2 Acetone.
3.3 Dichloromethane.
3.4 ​​Anhydrous sodium sulfate.
3.5 10% sodium bicarbonate solution.
3.6 Peracetic acid solution: hydrogen peroxide: acetic acid = 2:1. 3.7 Aldicarb standard stock solution: accurately weigh 50.0 mg of aldicarb standard, place it in a 50 mL volumetric flask, add a small amount of dichloromethane to dissolve it, and dilute to the mark with dichloromethane. Prepare a standard solution containing 1.0 mg of zecarb sulfone per milliliter.
3.8 Standard solution for zecarb sulfone: Take 5.0 mL of the standard stock solution and dilute to 50 mL with dichloromethane. The concentration of the intermediate solution is 0.10 mg/mL. Take 1.0, 2.0, 3.0, 4.0, and 5.0 mL of the intermediate solution in turn and dilute to 100 mL with dichloromethane to prepare a standard series with concentrations of 1.0, 2.0, 3.0, 4.0, and 5.0 ug/mL.
4 Instruments
4.1 Electric oscillator.
4.2 Rotary evaporator.
4.3 Purification column: In a 1.3 cm (inner diameter) × 8 cm chromatography column, add 1 cm of anhydrous sodium sulfate, 4 g of Florisil, and 1 cm of anhydrous sodium sulfate. 4.4 Gas chromatograph: with a flame photometric detector. 5 Operation method
5.1 Sample treatment
5.1.1 Fruit: Wash and dry the sample, mash and mix the edible part. Weigh about 25g of the sample, accurate to 0.001g. Place it in a 250mL stoppered conical flask, add 100mL acetone-water (3:1), and shake for 0.5h. Filter through filter paper, rinse the conical flask and residue three times with 50mL acetone-water, and combine the filtrate. Concentrate to about 100mL under reduced pressure in a water bath at 45℃. Place the sample solution in a 250mL separatory funnel, add 5mL peracetic acid solution, and shake for 0.5h. Slowly add 50mL sodium bicarbonate solution and shake until colorless bubbles appear. Extract three times with 50, 25, and 25 mL of dichloromethane, combine the dichloromethane, dry over anhydrous sodium sulfate, and concentrate to 1.0 mL under reduced pressure in a water bath at 45°C for determination. 5.1.2 Peanut kernels, grains, etc.: Crush and mix the samples, and operate according to 5.1.1 "Weigh 25 g of sample and dry over anhydrous sodium sulfate." The extract is concentrated to about 20 mL. The chromatography column is first pre-washed with 25 mL of toluene-dichloromethane (1:1). Transfer the upper liquid into the column, discard the effluent, and elute with 50 mL (2:98) and 100 mL (1:1) acetone-ether in turn, collect and combine the two eluents. Concentrate to nearly dryness under reduced pressure in a water bath at 45°C, remove and blow dry with nitrogen. Add 1.0 mL of dichloromethane to dissolve the residue and wait for determination.
5.2 Chromatographic conditions
5.2.1 Chromatographic column: Glass column: 1m long, 3mm inner diameter; Stationary phase: 15% FFAP/ChromosorbWAW 80～100HHHH
5.2.2 Detector: Flame photometric detector, S filter. 5.2.3 Temperature: Column box 190℃; Inlet 230℃; Detector 230℃. 5.2.4 Gas flow: Nitrogen 45mL/min; Hydrogen 80mL/min; Air 100mL/min. 5.3 Determination
According to the sensitivity of the gas chromatograph, take 5～10uL of each concentration of the standard series and inject them into the gas chromatograph respectively. Measure the peak height of each concentration of the standard solution, and draw a standard curve with the standard content (ng) under the injection volume as the horizontal axis and the peak height (mm) as the vertical axis. Take 5～10uL of the sample solution and inject it into the gas chromatograph. Measure the peak height (mm) of zedicarb sulfone and find the corresponding content (ng) from the standard curve. 5.4 Calculation
X(mg/kg)=mx×V×1000
W×V,×1000
Wherein: X—zedicarb content in the sample, mg/kg; the corresponding content of the sample peak found in the standard curve, ng; m
Vo sample liquid volume, mL;
W——sample weight, g;
Vi——injection volume, uL;
1000—unit conversion factor.
6 Precision
The relative standard deviation of this method is less than 13%.
7 Chromatogram and standard curve
The chromatogram of zedicarb is shown in Figure 1; the standard curve of zedicarb is shown in Figure 2. Approved by the Ministry of Health of the People's Republic of China on January 24, 1994 and implemented on August 1, 1994
GB/T14929.2—1994
Additional notes:
Weirong standard product, price product illustration
Picture of Dawei Biao Yashan
This standard was proposed by the Health Supervision Department of the Ministry of Health. 2
This standard was drafted by the Beijing Municipal Health and Anti-epidemic Station, the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, and the Institute of Plant Protection and Environmental Protection of the Beijing Academy of Agricultural and Forestry Sciences. The main drafters of this standard are Sun Chun, Jiao Shuzhen, Gao Xuande, Shi Jiancheng, and Liu Jie. This standard is interpreted by the Ministry of Health's Food Hygiene Supervision and Inspection Institute, the technical unit entrusted by the Ministry of Health. Approved by the Ministry of Health of the People's Republic of China on January 24, 1994 and implemented on August 1, 1994
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