This standard specifies the method for determining the residues of diflubenzuron in plant foods. This standard is applicable to the determination of diflubenzuron in grains, vegetables and fruits. The detection limit of this method is 0.3ng; the detection concentration is: 0.03mg/kg; the linear range is: 1ng～10ng. GB/T 5009.135-2003 Determination of diflubenzuron residues in plant foods GB/T5009.135-2003 Standard download decompression password: www.bzxz.net

IC867.04C
National Standard of the People's Republic of China
GB/T5009.135—-2003
G634-159
Determinatiun of chlorhenzaron residues in vegetable foods foods2003-08-11 Issued
Ministry of Health of the People's Republic of China
National Chemical Engineering Committee of the People's Republic of China
2004-01-01 Implementation
1993 Determination of the maximum amount of toxicity in foods, this standard replaces GH/T16340
Compared with BT640-1596, the main changes in this standard are as follows: GB/T5009.135-2003
The Chinese name of the standard has been changed, and the Chinese name of the standard has been changed to Determination of the maximum amount of toxicity in foods of plant origin Part 4, and the chemical analysis method has been changed to the original standard composition - according to GT2001.-2001 standard writing.
This standard was proposed by the Ministry of Health of the People's Republic of China and is the original standard. The unit to be consulted with is: Jilin Province Food and Drug Administration Inspection and Revision Center. The main contributors to the wood standard are: Shang Binfu, Jin Xiuhua, Fang Suguang, Zhang Wei, Chang Xin. The original standard was first published in 1996, and this time it is a screening - the first revision. 171
GB/T 5009.135—2003
Trichloroethane (1-chloro-2-yl)-1-(4-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1-chloro-2-yl)-1 5009.135—2063
After the inactivated chloramphenicol in the sample is extracted and purified, it is determined by a high-pressure chain chromatograph with a UV detector and compared with the standard solution for quantitative determination. 3 Reagents
3. 1 3.2: 30~60℃
3.3 Sequence,
3.4 ​​Extraction solution, two bottles of indole ether (3+4). 3.5 Liquid chromatography subtraction phase. Methanol-water (75+20), 3.6 Silica gel adsorption agent pretreatment column (see Figure 1). 3.7 Sterilization standard drop wave Accurately weigh 0000 sterilization standard (pieces of methane grid transfer 100ml volumetric flask, use dichloromethane to determine the guest, get 100/cut standard preparation, keep 100 times and get! g/12 standard use bag
2-, reverse treatment small standard,
Cause 1 Pretreatment volume
4 alarm and equipment
rate! High-efficiency laser spectrometer, with external detector, 4,225ml ratio:
4.3KE concentrator,
4.4 high-speed disperser.
1.5 electric centrifuge: 10 00c /min
4.6 its milling density centrifuge,
10 sensitive syringe
GB/1' 5009.135—2003
5 Analysis Procedure
5.1 Sample Preparation
5.1.1 Sample Crushing
Root food samples were crushed by a crusher and passed through a 40-day sieve. Vegetable and fruit samples were crushed by a grinder. 5.1.2 Sample Extraction
Weigh 2.500 g of the crushed sample accurate to C.201 and collect 50 ml of it. Centrifuge at a speed of 100 μl/min and add 10 ml of the extract. In an electric centrifuge F, extract at a speed of 100 μl/min for 5 min. Add 3 μl/min and let stand for 5 min. Centrifuge at 2000/min for 5 min. n, transfer the supernatant to a 25ml colorimetric tube; add 5mL of the extract to the precipitate, disperse and centrifuge, and then transfer the supernatant to a 25ml colorimetric tube, and then transfer the supernatant to a 25L colorimetric tube. Use the extract to make up to 2F [-, and get the test sample extract. 5.1.3 Purification of sample extraction
First, let 10mL of petroleum aldehyde flow naturally through the pretreatment column, and then use 10mL of dichloromethane to elute the column (see Figure 1) and discard the effluent. Then take 10mL of the sample and let it flow naturally through the column. The effluent concentrate is collected in a pear-shaped bottle with a KD shrinkage coupon; then use 15mL of dichloromethane to elute the column, and the effluent is transferred to the upper chestnut-shaped bottle. In a ventilated water bath at 40°C, blow dry the solvent in the soft bottle with ammonia, add chlorine, and store it in a cool place for a long time.
5.2 Sound effect phase color enhancement test case
Stainless steel: 20Cmm×4.m (inner diameter), fixed phase, C (5m chain phase: string drop-water (75+25), slurry speed: 1 mI./min.
5.3 Drawing of standard curve
Take 0.1, 3.5, 7, 10 μL of the standard solution of chloramphenicol and calculate the content of chloramphenicol respectively, and put it into the chromatograph to prepare the standard curve by comparing the concentration of the component to the peak height. 5.4 Determination
Then, the sample was filtered through a 5 μm microporous filter and 10 μL was immediately put into the chromatograph for determination. Calculate the peak area or quotient and calculate the concentration of chloramphenicol in the sample solution using the standard curve. 5.5 Calculation of results
Calculate according to the following formula:
Where:
X—the content of chloramphenicol in food in milligrams per gram (mg/kg) g): The concentration of chlorinated hemp in the sample obtained by standard filtration, in grams (rug/mL): V-the volume of the precipitate, in milliliters (ml); the volume of the sample filtrated on the column, in milliliters (rm1.); 5-the volume of the precipitate used to decompose the sample, in milliliters (rT.); -the volume of the sample residue, in grams (g);
The sieving result shall be two valid values.
6 The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 15% of the calculated average value. 174
Color diagram of the reference diagram is shown in Figure 2 bzxz.net
Standard color diagram of chlorinated hemp
GR/T 5009.135-2003
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