This standard specifies the method for the determination of pentachloronitrobenzene residues in food. This standard is applicable to the determination of pentachloronitrobenzene residues in grains and vegetables. The detection limit of this method is 5×10 GB/T 5009.136-2003 Determination of pentachloronitrobenzene residues in plant-derived foods GB/T5009.136-2003 Standard download decompression password: www.bzxz.net

1CS 67.040
National Standard of the People's Republic of China
GB/T5009.136—2003
Replaces GB/16341-195e
Determination of quintozene residues in vegetable foods2003-08-11Promulgated
Ministry of Health of the People's Republic of China
National Standardization Administration of China
2004-01-01Implementation
GB/T 5009.136—2003
This standard replaces GB/T163411996 Determination of pentachloronitrobenzene in food3. Compared with GB/T16341—1995, the main changes of this standard are as follows: The Chinese name of the standard is modified, and the Chinese name of the standard is changed to Determination of pentachloronitrobenzene residues in plant-based foods3: The current standard is written in accordance with GB/T23001.4-2001. Part 4: Chemical analysis methods. The original standard has been revised.
This standard was proposed by the Ministry of Health of the People's Republic of China. The standard was drafted by the Health and Epidemic Prevention Station of Lin Province. The main drafters of the standard in 2009 are: Li Kuichun, Li Qing, Jin Xiuhua, Li Chiguang. The original standard was first issued in 1996. This is the first revision. 178
1 Scope
GB/I ​​5009.136-2003
Determination of pentachloronitrile residues in plant foods This standard specifies the method for determining pentachloronitrile residues in foods. This standard is suitable for the determination of pentachloronitrile residues in grains and vegetables. The detection limit of this method is ×15-=ng: the minimum detection concentration when sampling 5.0g of food is g.c05mg/kg, and the minimum detection concentration when sampling 1.0g of vegetables is 0.U1nug/kg. The range of standard carriers is 0.005μ/mL~0.150g/ml1.! 2 Principle
The test sample is treated with hexane for purification, and then determined by gas chromatography electron microscope and compared with the standard series. 3 Reagents
3.1 Normal alkali: redistilled.
3.2 Acetone-hexane (1+9)
3.3 Anhydrous sulfuric acid
3.4 ​​40g/L sodium chloride aqueous solutionwww.bzxz.net
3.5 Pentachloronitrobenzene standard solution: Accurately weigh 0.0100g of pentafluoronitrile (yuir1czene), dissolve it in n-alkane, transfer it into a 1CCmL volumetric flask and fix it with 1:1 hexane to obtain a sodium solution with a concentration of 10 μg/mL. Add 100 times the stock solution to make a standard solution with a concentration of 1 μR/mL.
3.6 Pentachlorobenzene standard use: the collected solution was prepared into liquid concentrations of 0.00, 0.010, 0.050, 0.100, and 0.130 μg/mL respectively.
3.7 Testing medium: CriamnibWAW80--100, 3.B OV:7 and QF-1
4.1 Gas chromatograph, neutron capture detector: 4.2 Dimensional linear crusher.
4.3 Centrifuge
2.4 High-speed fractionator,
4, 5 small crusher,
2.6 Silica magnesium adsorption color treatment small hanger (see Figure 1) 111
Social radiation full:
small.
GB/T 5009.136—2003
4.7U micro-note.
4.8KD concentrator flexible bottle.
5 Analysis steps
5.1 Extraction
5.1.F food, take 5.08 ml of the sample that has passed the 45-day sieve and put it into a centrifuge tube, such as 20 ml of n-hexane high-speed disperser (1nr/min) for 4min at a centrifuge (2nnr/min), transfer the sample into a 25n volumetric bottle, add 5 ml of n-hexane to the high-speed disperser to extract, and wait for the extract to be mixed. Make up to 25.0 ml.5.1.2 Wash and chop the edible part, and crush it with a hot crusher. Add quantitative vegetable base to the sample. Collect the 1.C original test slurry that is quite dry, put it in a centrifuge tube: add 5 ml of n-hexane. Disperse it in a high-speed separator (1) (10) r/min, 4min, high speed centrifuge 20001/min>5min. Transfer the liquid into a 10ml volumetric flask, add 3ml of n-hexane to the centrifuge tube for extraction, combine the two extractions and filter, and add 10.Cml.
5.2 Purification
5.2.1 Pretreatment: First, pretreat the tube with 1m1 propane-n-hexane (1-9) twice, and then rinse with 1mJ of propane 5.2.2 Collect the sample 511 in the pear-shaped bottle of KD concentrator: elute with acetone-n-hexane (1-9) 3m=, add the remaining pear-shaped bottle of KD concentrator, blow nitrogen to concentrate to 1niT. 5.3 Gas chromatograph test equipment 5.3.1 Vaporization chamber (injection 1) temperature: 230℃. 5.3.2 Test temperature: 230℃.
Column length: 190
Gas flow rate: 0ml./min.
5.3.5 Column: 3mm inner diameter column length 1.5m, filled with 1.5% (V-17-2% QF-1 stationary liquid, support body is Bo 2000 hromgorbwAw.
5.4 Determination
Take 1L of pentadienyl standard liquid and use the total sample to determine it by gas chromatography, or directly compare it with the standard, calculate the total concentration of pentadienyl in the test.
6 Result calculation
6. 1 Calculate
Press the following formula:
Where:
The content of 1,2-dichlorothiocyanate in food, in milligrams per gram (mg/kg). 4
The mass of 1,2-dichlorothiocyanate in food is calculated by standard practice, in nanograms (ng)! The volume of sample injected into the chromatogram, in liters (μT); the volume of concentrated chromatogram, in liters (m) +
The total volume of extracted chromatogram, in milliliters (ml): V,--the volume of purified chromatogram, in milliliters (ml); the mass of the sample is grams ().
6. 2. The absolute difference between two independent determination results obtained under single and complex conditions shall not exceed 1% of the arithmetic mean value. 180. The gas chromatographic course is accompanied by a color diagram (see Figure 2).
Five basic gas chromatographic standard reference group
B/T5009.136—2003
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