This standard specifies the method for determining the residue of diflubenzuron in plant-derived foods. This standard is applicable to the determination of diflubenzuron in grains, vegetables and fruits. The detection limit of this standard is 0.40ng. If the sample is 2.5g, the detection concentration is 0.04mg/kg. The linear range of this standard is 1ng～10ng. GB/T 5009.147-2003 Determination of Diflubenzuron Residues in Plant-derived Foods GB/T5009.147-2003 Standard download decompression password: www.bzxz.net

[(S 67.040
National Standard of the People's Republic of China
GB/T5009.147—2003
G8/T7333—1s98
Determinatien nf diflubenzuron residues in vegetable foods2003-08-11 Issued
Ministry of Health of the People's Republic of China
National Mongolian and Yazhou Municipal Commission of Health
2004-01-07 Actual Can
GB/T 5009. T47—2003bzxZ.net
This standard replaces GB/T 6B/7333—1958 Determination of insecticide residues in food. The main differences between this standard and GB/T 17333—1998 are as follows: The text name of the standard is changed, and the Chinese name of the standard is changed to Determination of insecticide residues in food. The rules of GB/20CC-42001 are revised. Part 4, Chemical analysis methods, and the structure of the standard are modified.
This standard is from the Ministry of Health of the People's Republic of China. The responsible drafting unit of this standard: Health and Epidemic Prevention Station of Jiangxi Province: Main drafters: Gao Ligong, Yang Mingyuan, Bian Zu, Gong De, Zhang Guanying. The original standard was published in 2003. This is the first time.
-Yin Xinting
1 Scope
Determination of insecticide residues in plant products This standard specifies the method for determining insecticide residues in plant foods. This standard is applicable to the determination of insecticides in root foods, vegetables and fruits. The detection limit of this standard is c,10nR. If the sample is 2.5g, the criterion is 9.04mg/kR: The detection range of this standard: 1ng--10ng
2 Principle
CB/F 5009. 147-2003
The insecticides in the sample are extracted and chemically determined by a high-efficiency ultraviolet spectrometer with only ultraviolet detection, and compared with the standard for qualitative determination.
3 Reagents
3,1 3.2 Aldehyde: 30℃~50℃
3.3 Alcohol,
3.4 ​​Extraction: methane-unadjusted ether (3+4). 3.5
Hong Kong phase chromatograph: medium alcohol water (75+25), 3.6 Iodine adsorption agent pretreatment (see Figure 1). 3.7 Standard solution for deionized water: accurately weigh 0.0100g of deionized water standard (dilubenzuton, 98% iodine) and decompose it with dichloromethane and transfer it to 190ml. Deionize with dichloromethane to obtain a 100/mL standard solution. After dilution 100 times, a 100/ml standard recovery solution is obtained.
4 Instruments and equipment
4.1 High-performance liquid chromatography: with UV detector 4.225 ml. Colorimetric parts,
4.3 Split bottle of KD concentrator.
4.4 High reverse disperser
4.5 Electric centrifuge: 10000/min,
1. 6 High centrifuge tube with rotating port.
4.710L syringe
5 Analysis steps
5.1 Sample preparation
5.1. Preparation of samples
Grain samples are crushed by a pulverizer and sieved through a 4C sieve. The whole sample is crushed by a tissue crusher. 5.1.2 Sample extraction
Weigh 2.>*accurate to 0.00: put the powdered sample into 50mL of centrifuge, add 1CmL of extract, place in a commercial separator for 5min, add a stopper for 30min and disperse for 5min, centrifuge at 2000r/min for 5min, transfer the supernatant to 25ml. colorimetric tube: add 5ml. extract to the precipitate, disperse and centrifuge, and add the supernatant to a 21ml. colorimetric tube, weigh once, and the supernatant is also added to 249
CB/T 5009.147—2003
25mL colorimetric tube, dilute to 25mL with extracting solution, add sample solution. 5.1.3 Purification of sample extract
First, pass 10ml of petroleum aldehyde through the pretreatment column, then wash the column with 5ml of methane monoxide, discard the effluent, then take 10ml of sample extract, let it naturally pass through the column, drip into the pear-shaped center of the concentrator, then elute the column with 15ml of methane, and the effluent will be put into the standard bottle. In a ventilated place, under a water bath, blow out all the volatiles in the sample with a wide air, and store in a cool and humid place.
5. 2 Liquid chromatography reference conditions
No calcium: 200mm x 4.6mm (inner diameter); stationary phase: Ca (5mm mobile phase, acetylene glycol water (s+25) flow rate: 1mT/min
5.3 Standard electrolyte salt starting point
Take the standard salt solution of 0,1,2,3,5,7.1±1. (the salt solution content is 0,1,2,3.,7,10nR respectively), inject it into the chromatographic determination, use the sensitive scale to calculate the peak height to prepare the standard koji age, 5. 4 Determination
Add 1mL of methane monoxide to the dye bottle of the KD device to quickly dissolve the sample, take 10L of the solution and inject it into the chromatograph to read, calculate the peak area or peak height, and use the standard calibration film to screen the concentration of the sample solution. 5. 5. Calculation of results
The content of the main ingredient in the sample is calculated according to the following formula: e..
The content of the main ingredient in the single physical food, the unit is mg/kg: the concentration of the main ingredient in the test solution calculated by the standard, the unit is microgram per milliliter (μg/mL) + V,--the fixed volume of the sample extract, the unit is milliliter (μL): W.
--the volume of the sample extracted, the unit is m2 (m2); V,--the volume of the solvent used for the sample, the unit is m3 (m); the sample mass, the unit is gram (g).
The calculated results shall be expressed with two valid numbers. 6. Precision
The absolute value of two independent determination results under quantitative conditions shall not exceed 15% of the arithmetic mean. 7. Chromatographic reference diagram
shows 1:
The range 1 is the standard chromatogram of the pig.
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