This standard specifies the method for determining the residue of oryzalin in rice. This standard is applicable to the analysis of the residue of oryzalin in rice. The detection limit of this method is 0.26ng; if 20g of rice sample is taken, the detection concentration is 0.013mg/kg. The standard linear range is 0ng～15ng. GB/T 5009.155-2003 Determination of the residue of oryzalin in rice GB/T5009.155-2003 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T.5009.155—2003
Replacement (BT174C6-1998
Determination of isoprothiolane residues in rice
Issued on 2003-08-11
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on 2004-01-01
This standard replaces GB/T17408-1998 Determination of isoprothiolane residues in rice 3. The main changes of this standard compared with GB/T17409--1998 are as follows:
GB/T 5009.155—2003
Repealed B/T20C0:1-2001 & Standardization Rules Part 4, Chemical Analysis Method Modified the structure of the original standard,
This standard is issued by the Ministry of Health of the People's Republic of China. The responsible person for this standard: Sichuan Provincial Health and Prevention Station: The main drafters of this standard: Xiang Shixue, Xie Tuojun Fangyequn, Xiao Xueyi, Fu Song. The original standard was first issued in 1, and this is the first revision. 97
GR/T 5009.155—2003
Xuyan, also known as Dangshi No. 1 (Zheng T), has the chemical name of 1,3-diisopropyl 2-propanediol, a low-reactivity agent, and is a special medicine for preventing and treating smallpox (leaf cancer and smallpox). The drug has been registered on rice in China. my country stipulates that the residual concentration of rice frostbite in rice is 1.0 mg/kg. This standard provides a method for detecting rice frostbite residues in rice. 255
Determination of the residual amount of rice frostbite in rice
This standard specifies the flash determination method for the residual amount of rice frostbite in rice. CB/T 5009. 155---2003
This standard is used for the analysis of the residual amount of rice frostbite in rice. The detection limit is 0.26 ng. If the sample is 2 ng, the control concentration is 0.013 mg/kg. The standard linear range is 1 ng~15ng
2 Principle
The residual pesticide in the sample is removed by organic binder, and then purified by a series of steps such as purification with good adsorbent, and then determined by gas chromatography with flame photometric detector: the result is qualitatively determined by retention time, and quantitatively determined by comparing the peak quotient of the test sample with that of the standard. 3 Testbzxz.net
3.1 Acrylic acid: Algae.
3.2: Methane: Distilled
3.3 Anhydrous sodium sulfate Na.S3,).
3.4 ​​Silica gel adsorbent: G0~: 00 months, calcine at 550℃ for 5 hours to activate with water, set to above 130% before use, and then deionize with % water and balance for use. 3.5 Standard sogrochialane foil: Accurately weigh the sogrochialane standard (sogrochialane) The pure liquid a is 97.5%>, and is prepared into a 1.1 mg/mL standard stock solution with acetone and stored in ice. When used, it is diluted with ketone to form a 1.0\g/mL standard solution using a filter. 4 Instruments and equipment
4.1 Gas chromatograph: equipped with flame photodetector (FPD).
4.2 Small pulverizer.
4.3 Electric vibrator.
4.4 KD concentrator.
5 Analysis steps
5.1 Sample preparation
The sample is powdered and sieved through a 20-day sieve: Weigh 20x sample, accurate to C.501g and place in a sieve 5.2 Extraction
Add 5cmL of liquid to the above sieve, vibrate on an electric vibrator for 30 minutes, drain through a fast-fixed clean paper in a sieve, and use 30ml of acetone to extract the residue again: use 31rml of acetone. The residue was washed with ketone in batches, and the concentration was nearly ten times in 150-150 dichloromethane.
5.3 Purification
5.3.1 Preparation of chromatographic column
Load 2cm of sodium sulphate aqueous solution on a chromatographic column (2cmXx200mm), weigh 10g of silica gel adsorbent and load it into the column, and load 2c high anhydrous flow cell, elute the purification column with 20ml of dichloromethane and discard the elution. 5.3.2 Purification of sample extract
Dissolve the sample with a small amount of monoxide, slowly pour it into the chromatographic product, discard the effluent, and elute with 10gml of monochloroethane at a rate of 0.5ml/ml~1.0mL/tir. Collect the effluent and transfer it to a KD bottle. Concentrate it under reduced pressure to less than 1.0mL, wash it with acetyl ether and continue to condense it to less than 1.0tnL. Finally, make up the volume with propylene to 1.0ml. 5.4 Chromatographic system
CB/I5009.155-2003
5.4.1 Chromatographic glass: 3mmX110mm glass, filled with 20V.17 Chromochrome A/W-DMCS (e00g/g). 5.4.2 Temperature seat, pull temperature 235℃: + instrument vaporization humidity 250℃ 5.4.3 Gas: oxygen purity ?, ssA%), 70ml./min Hydrogen: 68.7kIa Air: 83.3kPa. 5.5 Intense
Take the standard and sample purification liquid each 1.! ., repeat 3 times respectively: qualitatively determined by retention time, and calibrate the record by comparing the average peak height of the sample with the average peak value of the standard. Under the above color conditions, the retention time of chloramphenicol is about 2.6min:
6Result calculation
Using the fluorescent stool test group (FPD>, the square of the concentration of 394n contained in the solution is proportional to the response value. When the sample conditions of the standard and the sample solution are the same, the concentration of chloramphenicol in the test solution is calculated according to formula (1). =dxk
Wherein,
The concentration of chloramphenicol in the sample solution is micrograms per liter (/mL); The concentration of chloramphenicol used in the standard solution is micrograms per milliliter (&/IuL)2
The drop of chloramphenicol in the test solution is expressed in millivolts (mmV); The drop of chloramphenicol used in the standard solution is expressed in millivolts (mV) [nmmV)_night ratio (1) after calculating G, substitute into formula (2), calculate the test volume. X.SxV
wherein,
X-1. The content of rice box spirit in the sample, the unit is milligram per gram (mg/kg), V
the constant volume after the test explosion and purification, the unit is liter (ml). The mass of the sample, the unit is gram (g).
The calculation results are guaranteed to be valid.
In order to ensure precision
the absolute difference between two independent measurement results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean value, 8 gas chromatographic test field
see Figure 1.
The standard chromatographic range is directly related to the color space of the product.
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