GB/T 5009.25-2003 Determination of sterigmatocystin in plant-derived foods

This standard specifies the determination method of sterigmatocystin in various plant-derived foods such as rice, corn, wheat, soybeans and peanuts. This standard is applicable to the determination of sterigmatocystin in various plant-derived foods such as rice, corn, wheat, soybeans and peanuts. GB/T 5009.25-2003 Determination of sterigmatocystin in plant-derived foods GB/T5009.25-2003 Standard download decompression password: www.bzxz.net

S67,04c
National Standard of the People's Republic of China
GB/T5009.25--2003
Replaces H/T5005,25—1996
Determinatlon of sterigmatocyslin in vegetable foods2003-08-11 Issued
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
2004-01-01 Implementation
GU/T5009.25—2003
This standard replaces GB/T500C.25199 Determination of colorimetric substances in foods3 Compared with GB/T5009.25—1996, the following changes have been made to this standard: The Chinese name of the standard has been modified, and the Chinese name of the standard has been changed to Determination of colorimetric substances in physical foods3! ... The current standard is compiled in accordance with GB/T20001.4-205 standard Part 4: Chemical analysis methods? The conclusions of the original standard are revised7.
This standard is issued and managed by the Ministry of Health of the People's Republic of China. The first method of this standard was drafted by the Food Hygiene Supervision and Inspection Institute of the Ministry of Health and the Tianyang Municipal Health and Hygiene Station. The Institute of Nutrition and Food Hygiene of the Chinese Academy of Preventive Medicine was responsible for drafting. This standard was first issued in 1985, revised for the 15th time, and revised for the second time this time. 254
1 Scope
Determination of sterigmatocystin in plant foods GB/T5009.25—2003
This standard specifies the determination method of sterigmatocystin in various plant foods such as rice, corn, millet, soybean and peanut. This standard is used for the determination of sterigmatocystin in various plant foods such as rice, corn, millet, soybean, peanut, etc. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For any referenced document with a date, all subsequent amendments (excluding errors) or revisions are not applicable to this standard. However, the parties to an agreement on technical standards are encouraged to study whether to use the latest versions of these documents. For undated referenced documents, the latest versions are applicable to this standard GR/T 5009.22-2003 Determination of yellow koji in food 3 Principle
After the yellow koji in the sample is extracted, purified, concentrated, and developed, it is colored with aluminum hydride and then heated to produce a substance that shows yellow fluorescence under ultraviolet light. The fluorescence displayed on the thin layer is used as the basis for determining the content of yellow koji in the sample. 4 Reagents
4.1 G/T 5008.22-200.13.4.
4.2 Glacial acetic acid
4.3 Formic acid.
4.4 (95%)
4.5 Sodium chloride solution (40R/1.)
4.6 Dioxide·ethanol solution (200g/L): weigh 20g aluminum chlorideRemove and filter in 100 μl ethanol and store in a refrigerator.
4.7 Standard solution of 15 μg/mL 1.0 ... 5.1 Same as G/5009, 22-203 4.1~-4.4.5.2 Glass plate, 10cmx10cm and 10cm×R,5cm, 5.3 Extension profile inner length 10cm, width 4.5cm, height 17cm and inner length 11.5cm, height 50cm, 15cm, 5.4 Glass thickness.
5.5 Gas or oil content. 6 Analysis step 6. Take corn, corn, peanut, soybean and snapper, weigh the corn, corn, wheat and soybean samples (the peanut sample is sieved through 205
GD/T 5009.25-2003
10|| mesh), put them in a 250mL flask, add 0ml of sodium chloride solution (90+10), shake for 30min, collect 40ml of the sample (for soybean and snapper test, take 2gml and add 20ml of sodium chloride solution), transfer it into a 250mL separatory funnel, add 25l of sodium thiocyanate solution (so that the ratio of sodium thiocyanate to water is 6+45), add 25ml of petroleum ether, stir for 2min, and let it stand for stratification. The upper layer of petroleum ether was dropped into a drain pan, and the lower layer of solution was still placed in the original separatory bucket and extracted once with 23 ml of petroleum ether. The upper layer was vortexed and crushed together, and 25 mL of 2 M methanol-sodium chloride solution (+5) was added, and 3) soybean and peanut samples were decomposed into ethanol and diluted with oil (76+31.30). The lower layer was placed in the original water layer, and the soybean and peanut samples were extracted twice with sodium hydroxide (55+45). The soybean and peanut samples were then extracted with methanol-sodium chloride solution (70+30) to extract the desired ingredients in this layer. 30 mL of trifluoroethane was added to the lower liquid, and 11 mL of sodium fluoride was added to the soybean and peanut samples except for monofluoromethane, so that the volume ratio of methanol to water was 53-4. The mixture was allowed to stand for 21 minutes, and the upper layer was collected according to the liquid change. The liquid of each layer was then placed in a quantitative slow oxygen filtration with about 1 mL of anhydrous sodium sulfate. Reduce the pressure and boil the solution. Cut 10 ml into a separate bucket. Add trioxane, repeat the process once, wash the lower layer of the solution with a small amount of trioxane and put it into the blood sample: place the blood sample on a plate with water, then stand on ice for 2-3 minutes, add 1.0 mL of the sample and put it into a small test tube, or transfer the sample to a concentration tube with methane, frost it to 10% by vacuum blowing, add 2.3 mL of apple, and use it for chromatographic determination. 1 ml of corn sample is equivalent to 10 g of test sample, and 1 mL of yellow and peanut sample is equivalent to 5 g of test sample. 6.2 Determination
6.2.1 Preparation of thin film display plate
Preparation method is the same as /T500S.22-20C 5. 3.1.1. Use 5g of extended gel G to make five 1cm×10cm, 0.3μm layer plates:
6.2.2 Sample Spotting
Take two 1cm×10μm sea layer plates, and drop 10l of standard solution (0.4g/ml) at 0.cE~1cm from the bottom of the plate and 1m below the sample solution. Add 80ml of sample solution (soybean and peanut samples are 40ml) at 1m from the edge. Then add 10ml of standard solution (0.4/ml) to the sample solution spot on the second plate, and blow the filter with cold air from the blower.
6.2.3 Development
6.2.3.1 Horizontal Development The developing agent is aldehyde-n-hexane-chloroformate-formic acid (3 1911.: 11,5 + 0.615,6m (in this case, the liquid does not contain a phase, and the amount of each expansion should be melted separately): before fully selecting: pour into the belt for use. Near the standard point, put the cotton inside the expansion sheet\em and take out the thousand: 6.2.3.2 longitudinal expansion, the developing agent is this-methanol-ice art ten% one 2 station 2.5 + 6 ten 1.5> 15mL, put the side close to the standard point and the sample into the collection, expand\m and take out the upper library ten. 6.2.4 Display light
Spray the first layer of acetaldehyde solution on the full layer cabinet <20g/L, set 8% potential 10nin, and observe the results under the light of the east light<wavelength 365am. After the board is completely cooled, spray the sea thin medicine for the second time, and the results can be observed directly. 6.2.5 Observation and evaluation results
Under ultraviolet light, if the maximum detectable amount appears at the second point corresponding to the standard point of the second plate, and at the same position on the first plate, the sample solution is below 5/20g (for soybean and peanut test, it is below 20g). If the intensity of the sample solution fluorescence point is equal to the fluorescence intensity of the minimum detectable amount at the standard point, and this fluorescence point is consistent with the standard point of the second plate, then the adenomatous toxin content in the sample is 5g/kg (20g/kg for yellow blue sample); if the fluorescence intensity is stronger than the maximum detectable amount at the mark point, then the fluorescence intensity is estimated to decrease by adding different microliters. After the sample solution is diluted, add different microliters of oxygen until the fluorescence intensity at the sample solution point is the same as the intensity of the minimum detectable amount. After each inspection and evaluation, the results should be consistent. If the result is positive, then the layer should be placed at the same time, and it can be inspected once. If the sample is positive, further confirm the test by dropping 10 standard working liquid (0.4rg/ml) at each point on a 3cm base layer (10m13.5cm) at 3 points. Add 1 standard working liquid (0.4rg/ml) at each point and 16 sample liquid at each point. Add 1 standard working liquid (1\gm) at each point. Apply a small amount of three-effect liquid to each point, and spray the point with hot air for 1mia. 5ain reduce 22:h
GB/T5009.25—2003
the temperature on the plate is not higher than 4 ball acetic acid-and (1 ten) expand 1 happy one 3 times, until the end of the colorful classic barrier of biological one pulls the mountain. The next step is to observe the plate under the forbidden light, the woman's column should produce a positive biological overlap with the colorful standard: the low detection benefit is not reached, the wheat is 2 three g (yellow, the flower sample is bo 1R/kg:.
6.3 Calculation of results
The content of the colorant is calculated according to formula (1), V, X D.1 OGC
Wherein:bzxz.net
Colorant content, unit is ug/kg; V--the product of the same solution, unit is milliliter (E); The minimum fluorescence sample volume, unit is mL! : The total effective rate obtained by the concentrated sample;
The sample is calculated according to the sample policy, unit is gram (g); The minimum and maximum values ​​of the colorant per parent are recorded as grams (g), and the results are expressed in the digits of the measured value,
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