GB/T 5009.175-2003 Determination of 2,4-D residues in grains and vegetables

This standard specifies the method for determining the residual amount of 2,4-D in grains and vegetables. This standard is applicable to the determination of the residual amount of 2,4-D in grains and vegetables. The detection limit of this method is: 0.008 mg/kg for vegetable samples; 0.013 mg/kg for raw grain samples; the detection range is: 0.01ng～10ng. GB/T 5009.175-2003 Determination of residual amount of 2,4-D in grains and vegetables GB/T5009.175-2003 Standard download decompression password: www.bzxz.net

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National Standard of the People's Republic of China
GB/T5009.175—2003
Determination of 2,4-D residue in grains and vegetablesDeterminantitn of 2,4-D irt grains and vegetables2003-08-11Promulgated
Ministry of Health of the People's Republic of China
China National Standardization Administration
2004-01-01Implementation
This standard was proposed and coordinated by the Ministry of Health of the People's Republic of China, and the responsible drafting units of this standard are Beijing Health and Prevention Station and Food Industry and Health Supervision and Inspection Institute of the Ministry of Health. The main drafters of this standard are Zhao Li, Zhang Ying, Shu Junxing and Yang Shuihong. GB/T 5009,175—2003
GB/T5009.1/5—2003
2.4-D (2.4-1) benzyl acetic acid type stimulant selective herbicide and plant growth regulator, with the chemical name of 2.4-dichloroethoxyethyl (2.4Lhchloraphthyl) is a low-toxic drug according to the market classification standard of Chinese medicines, and has been registered in my country as a special food.
The Chinese standard specifies the method for determining the residue of 2,4-D in food and vegetables. The standard specifies the method for determining the residue of 2,4-D in food and vegetables. This standard is applicable to the determination of the residue of 2,4-D in food and vegetables. The detection limit of this method is 1.008rmh/kg, and the linear range is 0.01mg/kg. 2 Principle
2.4-D of the sample is separated by organic solvent, 2,1-D of free 2,4-D of butylene oxide is filtered off, the sample is taken out by cage-liquid extraction, the sample is purified by chromatography to remove the cloudiness, and the determination is carried out by gas chromatography electron capture detector. According to the peak retention time of the color, the peak surface and the quantification by external standard method.
3 Identification
3.2 Acetaldehyde
3.3 Aldehyde; boiling range ℃.~50℃. 3. 4 Isooctane
3. 5 Propane
5 EH? Aldehyde aqueous solution is prepared with dilute phosphate, 3.6
3.753g/L sodium hydroxide solution.
Sodium hydroxide, calcine at 653℃ for 4h, and stored in a desiccator. 3.8
Eluent, 10% ether (S55). 3.9
3.10 Derivatizing agent: 14% triazine trichloride solution. 3.112.4 Standard drop: 2.4-1 (2.4-1), purity 9a.9%), is prepared into 1.00 mg/ml solution with methanol. 4 Instruments and equipment
4.1 Gas chromatograph: its electronic auxiliary detector. 4.2 Feed the pulverizer.
4.3 G oil filter.
4.4 Purification; PT silica adsorbent color treatment. Fill a small container with 0.4g of 65-80g of silica adsorbent. Before use, use 5ml of petroleum gasket.
4.5 Analysis air 20ml. Sheet, matching sealing pad, 5 analysis steps
5.1 Extraction: Weigh 50g of root sample, with an accuracy of c100=]. Add 30mL of ether and 2% acid water and mix well. Put the liquid in a crusher to make a polymerizable solid. Filter with G3. Wash the residue several times with 50mL acetaldehyde, transfer the filtrate to a 1.50mL separatory funnel, let it stand for stratification, and remove the water layer. Dehydrate the acetaldehyde layer with anhydrous sodium sulfate, add 1/2-isooctane and blow nitrogen until nearly 1/4: transfer to a 20L air separation glass with 5ml of methyl 3
GB/T5009.175-20C3
benzene. Crude grain: take 30g of powder after 2C sieve, add 20mL of 1.2mL of ethanol and vortex in a 3mL conical flask to extract 3min, filter with a (3) sand core funnel, and drain with 20mL 7. Wash several times, transfer the selected liquid into a 50mL separatory funnel, let it stand and separate into layers, discard the aqueous layer, dehydrate the acetaldehyde layer with aqueous sodium hydroxide, add 1L isooctane, blow air until almost dry, and transfer 5ml of the liquid to a 21ul empty analytical glass bottle in batches. 5.2 Derivatization In the above analytical chamber, cover the glass bottle, keep it in a water bath for 15 minutes, then cool the fraction by ice water, transfer the derivatized liquid to a 60mL separatory funnel containing 105% sodium hydroxide, collect it with 3.5mL ether, combine the organic phases, dehydrate it with anhydrous sodium sulfate, and then separate it into 21ul. 5.3 Preparation of 2,4-butyric acid standard
Take 10 μl of 2,4-butyric acid standard and prepare 2.4 μl of 3,4-butyric acid standard according to the method of 5.2. The content of 3,4-butyric acid in the solution is equivalent to 1.0 g/l. 2.1 ml
5.4 Purification
Purify the ether with nitrogen to nearly 10 ml. Place the ether tube in a well-treated ether tube, wash the ether with petroleum ether, add 20 ml of ethanol and elute with 2% sodium hydroxide + acetone (9F+F). Collect the eluted solution in a 25I colorimetric tube and blow down the concentrated solution for a while.
5.5 Gas chromatography test requirements
: 1.7% (2) V-17 and 2% QF15 standard solution. Effective body chromorsrb (HP>, 6i~R day, 2 m×32mmid) glass, column temperature 180℃, high pressure gas, washing 5umL/min, sample delivery, detector concentration: 2.m%:.5.6 chromatographic analysis
Use external standard method to standardize, complete yellow · respectively send 2.4-drops of biochemical standard to perform the analysis, inject 1 drop of each sample solution into the gas chromatograph: repeat the injection 3 times, and the error each time shall not exceed %, and use the maintenance time to determine the 2.4-full vinegar, and use the external standard method to perform the chromatographic peak area. Under the above conditions. The retention time of 2,4-D is 3 min. Calculate the following formula: S-AX-V-tt-c—2,1-D content in the sample, in milligrams per kg (mg/kg): V—standard sample injection volume, in micrograms per liter (g/m): A—sample volume, in milliliters (mL): V—sample injection volume, in microliters (μL); A—standard color block area; m—sample mass: in grams (g):? Precision
The absolute difference between two independent determination results under or without reconstitution conditions shall not exceed 10% of the arithmetic mean.:39
8 Gas chromatograph reference figure
National 12.4-Drop ketone standard chromatogram
Figure 2 Negative spectrum of food sample spiked
CB/I5009.175—2003
National 3 Vegetable sample spiked chromatogram
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