GB/T 5009.134-2003 Determination of gramineous chloranil residues in rice

This standard specifies the method for determining the residue of gramineous folate in rice. This standard is applicable to the determination of the residue of gramineous folate in rice that has been treated with gramineous folate as a herbicide. GB/T 5009.134-2003 Determination of the residue of gramineous folate in rice GB/T5009.134-2003 Standard download decompression password: www.bzxz.net

JCS67.~40
National Standard of the People's Republic of China
GB/T5009.134—2003
代琴GB/T163391S96
Determination of molinate residues in rice
Determination of molinate residues in rice2003-08-11Promulgated
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/T16239—1996 Determination of large and medium-sized firewood chicken weighing plate3. Compared with GB/T16339-1296, the main changes of this standard are as follows: CB/T 5009.134-2003 has collected the Chinese name of the standard, and the Chinese version of the standard has been adjusted according to the GF/T20001.4-2001 Standard Writing Rules Part 4: Chemical Analysis Methods> to make some adjustments to the original standard.
This standard is proposed and coordinated by the Ministry of Health of the People's Republic of China. The responsible drafting units are the School of Public Health of West China University of Medical Sciences, Sichuan Provincial Health and Epidemic Prevention Station, and the Provincial Institute of Labor and Health Occupational Diseases.
The main drafters of this standard are Fang Yaqun, Ban Qing, Zhang Wenshi, and Zuo Rui: The standard was first published in 1998, and this is the first revision.
GB/T 5009.134-2003
MolinEte, chemical name N,N-hexamethylethylenethiocarbamate, is a herbicide widely used in my country in recent years to control weeds.
This standard is formulated based on the determination methods of weed killers in foreign countries. Dry pillow test: Under the chromatographic conditions specified in this method, the determination of weed killer and weed killer is not disturbed by medium base. 186
1 Scope
This standard specifies the method for determining the amount of grass-roots bacteria in rice. This standard is intended for the determination of grass-roots bacteria residues in rice that has been subjected to quality control. GB/T 5009.134---2003
The detection limit of this method is 1.01mg/kg for 20% rice sample, and the detection range is 0.15 ug/mL--1.03 μg/mL.
2 Principle
The rice sample containing undesired substances is taken from water (1 + 1) and then filtered and quickly fermented in aqueous solution (3.5--3.5). The extract is cooled and concentrated in a silica gel chamber and then qualitatively determined by gas chromatography-mass spectrometry with flame photometry and the peak value is compared with the peak value of the standard series. 3 Test
3.1 Propanol: blue steam.
32 Shixianpan Buddha 30~50 yuan redistillation:
3.3 ether,
3.4 ​​anhydrous acid,
3.5 silicon magnesium adsorbent: 100 days 20% day, burn 3E at 550℃ and store in a dryer. Before use, deactivate the silica-magnesium adsorption with hot water for 1 h, balance it, mix it and use it. The volume release time should be more than two hours. It should be dried at 13 °C for 5 h before use. Then add water to deactivate it.
3.62.05 aldehyde,
3.7 This standard is used. Accurately weigh the mcliaate standard product and prepare it into a standard stock solution of Ftg/it. It is stored in the refrigerator (4.] and diluted to 1.0 μg/ml standard solution when used. 4. Apparatus and equipment
4.1 Gas chromatograph with a photopic detector (FPD) 4.2 Electric drug alarm.
4.3 Constant temperature water tank,
4. 4 4.5 Drum decomposition or rotary evaporation. 4.6 XD concentrator. 5 Analytical steps 5.1 Sample pretreatment 5.1.1 Extraction After the rice sample has been filtered for 20 min, weigh about 20 g of the sample, accurate to 0.001 + 1 mL of acetone (1:1) and extract for 10 min with a long funnel covered with a piece of fiber cloth, then rinse with 1 L of propionic acid water (1:1) for 3 to 4 times. Combine the filtrate and transfer to a 5001. dripping funnel, add 5.1.2 Load the less than 5g sodium hyaluronate in a 10mm column with 0.5% sodium hyaluronate, add 8g sodium hyaluronate, 5g sodium hyaluronate adsorbent, and use the oil percussion method to load the column. Add 20ml sodium hyaluronate and add 20ml sodium hyaluronate. When the surface of the adsorbent drops to the surface of the adsorbent, transfer the extract to the chromatographic column carefully through the extraction bottle. Use 5lmL sodium hyaluronate (1-1) to elute with a concentration of 1. mL/in, the collected element was despeckled, and the concentrator was decompressed in a constant water bath at 45 °C: the volume was adjusted to 100 mL. The sample liquid was placed in a water bath, and 2.1 was taken for gas phase analysis.
5.2 parts were analyzed
The gas chromatograph was a 2m×mm glass column filled with a GasChromQ carrier (B0 days to 100 months) with 3% 0V17. The column temperature was 200 °C, the temperature of the vaporizer and the detector was 220 °C, the sensitive gas washing rate was 40 mL/min, and the hydrogen flow was 55 m l./m:n, the air flow in the room is 300mL/nin.
5.3 The standard curve is prepared by mixing 0.00.19, 0, 20, 0.40.0.60.0.80.1.00/mL of the standard liquid. Take 2.0% of the standard liquid and inject it into the gas chromatograph under the above gas chromatographic test strips. Determine the color peaks. Repeat the determination 3 times. Take the level of the standard liquid as the coordinate and the color level as the standard to make the curve. 5.4 Determination
Take 2.0% of the purified test liquid and collect it in the gas chromatograph. Repeat the determination 3 times and measure the average value of the test peaks. In order to ensure the qualitative and quantitative results according to the standard line.
5.5 Calculation of auxiliary results
Since the response of the flame photometric detector (FPD) to sulfur at 394 nm is not linear, but proportional to the square of the concentration of sulfur in the sample. When the amount of sulfur in the sample is the same as that of the standard, the content of sulfur in the sample is calculated according to the formula X-GXVbzxz.net
In the test,
X--the content of sulfur in the sample, in grams per gram, V--the product of the mass of the sample to be tested, in milliliters (μg/milligram); m--the mass of the sample, in grams (μg/milligram);
--the density of the sample, in micrograms/milligrams). The calculation result should be guaranteed to have two valid digits
6 precision
The absolute difference of the independent determination results obtained in repeated tests shall not exceed 10 of the arithmetic mean. 168
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