GB/T 5009.200-2003 Determination of quaternium residues in wheat

This standard specifies the gas chromatography determination method for the residue of quail in wheat. This standard is applicable to the determination of quail residue in wheat. The detection limit of this method is 4.0 ng; the linear range is 0.5 Kg/mL～5.0Kg/mL. GB/T 5009.200-2003 Determination of quail residue in wheat GB/T5009.200-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.200—2003
Determination of difenzoquat residues in wheat
Determination of difenzoquat residues in wheat2003-08-11PromulgatedbZxz.net
Ministry of Health of the People's Republic of China
National Administration of Standardization of China
Implementation on 2004-01-01
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Pesticide Control Institute of the Ministry of Agriculture and the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. The main drafters of this standard are Gong Yong and Yang Dajin. GB/T5009.200—2003
GB/T5009.200—2003
Wild avenge, trade name: difenzoquat, chemical name: 1,2-dimethyl-3,5-diphenylpyrazole methyl sulfate. This pesticide is a selective post-emergence stem and leaf treatment agent, mainly used for the control of wild oats in barley, wheat and rye fields, and is moderately toxic to humans and livestock. This method is based on the analysis method of avenge pesticide of American Amine Company and combined with the conditions of Chinese instruments and equipment, and is suitable for the analysis of wheat.
1 Scope
Determination of avenge residue in wheat
This standard specifies the gas chromatography determination method for avenge residue in wheat. This standard is applicable to the determination of avenge residue in wheat. The detection limit of this method is 4.0ng and the linear range is 0.5μg/mL~5.0g/mL. 2 Principle
GB/T5009.200—2003
The wild avenge in the sample is extracted with an organic solvent, and after removing interferences by liquid-liquid partition, it is detected by a gas chromatograph with a nitrogen-phosphorus detector. The qualitative analysis is based on the retention time of the chromatographic peak and the quantitative analysis is based on the external standard method. 3 Reagents
3.1 Acetone.
3.2 Dichloromethane.
3.3 Anhydrous sodium sulfate.
3.4 ​​Sodium chloride.
3.5 Pesticide standard solution: Accurately weigh the wild avenge pesticide standard (Avenge, purity ≥99.99%), and use acetone to prepare a standard stock solution with a concentration of about 1.0 mg/mL. When used, dilute it with acetone to a standard working solution of appropriate concentration according to the sensitivity of the instrument. 4 Instruments
4.1 Gas chromatograph: equipped with a nitrogen-phosphorus detector. 4.2 High-speed tissue crusher.
4.3 Rotary evaporator.
5 Analysis steps
5.1 Extraction
Weigh 20g of the sample (accurate to 0.001g) and place it in a wide-mouth bottle of a high-speed tissue crusher, add 100mL of acetone, homogenize at high speed for 5min, filter, rinse the filter residue and container with 2×20mL acetone, and concentrate the filtrate to about 2.0mL using a rotary evaporator (40℃ water bath) for purification.
5.2 Purification
Add 50mL of 30% sodium oxide aqueous solution to a 500mL separatory funnel, transfer the concentrate to the separatory funnel several times with 50ml. difluoromethane, shake for 1min, let it stand and separate, collect the organic phase through anhydrous sodium sulfate, extract and collect with 2×50ml, dichloromethane, concentrate and transfer to a graduated test tube, make up to 1.0mL, and test. 5.3 Gas chromatography reference analysis conditions
5.3.1 Chromatographic column: HP-608.30m×0.53mmX0.5μm. 5.3.2 Chromatographic column temperature: starting temperature 150℃, heating rate 30℃/min, ending temperature 260℃, holding time 5min. 5.3.3 Inlet temperature: 240℃.
5.3.4 Detector temperature, 270℃.
5.3.5 Gas flow rate: nitrogen 13mL/min; tail gas 36mL/min;
GB/T5009.200—2003
hydrogen 4mL/min;
air 90mL/min.
5.3.6 Chromatographic determination: Under the above conditions, the retention time of wild swallowtail is 4.3min. 6 Result calculation
X-XhxV
Wherein:
X is the residual amount of wild yam in the sample, in milligrams per kilogram (mg/kg); — the concentration of the standard solution, in micrograms per milliliter (μg/mL); V is the final volume of the sample, in milliliters (mL) 1h. — the peak height or peak area of ​​the standard solution, h is the peak quotient or peak area of ​​the sample;
the mass of the sample, in grams (g).
The calculation result shall retain two significant figures.
Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 8 Chromatograms
Figure 1 Standard chromatogram
Sample blank
Figure 2 Sample chromatogram
Sample spiked (0.5 mg/kg)
Wild swallow 4.380
Sample spiked chromatogram
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