Method for determination of parathion methyl residue in fruit for export

SN 0161-1992 Test method for methyl parathion residues in exported fruits SN0161-1992 Standard download decompression password: www.bzxz.net

1 Subject content and applicable scope
ethod fo
This standard specifies the test method for methyl parathion residues in apples for export. This standard is applicable to the test method for methyl parathion residues in apples for export. 2. Sampling and sample preparation 2.1 Inspection batch No more than 1500 pieces are an inspection batch. 2.2 Sample size is 25-150 m2. 2.3 Sample preparation At least 500 g of each piece shall be selected as the original sample batch. The grade must be the same. The laboratory samples shall be selected from the pieces. The laboratory samples are: the same quantity, the same weight, the same size, the same weight ... The sample is taken with acetone, and then salted with trifluoroacetic acid. 3.2 Reagents and materials 3.2.1 Neutral aluminum hydride (for chromatography, 200~30: 400° calcined in a desiccator for later use, 3.2.2 Anhydrous sodium sulfate: analytical grade, calcined at 650°C for 4h, stored in a desiccator for later use. 3 Dichloromethane: analytical grade, redistilled. 3.2.4 Acetone: analytical grade, redistilled. 3.2.5 Sodium sulfate aqueous solution (2% sodium sulfate). 1: Add 20g of anhydrous phosphorus. Root index needs grapes to be compared with acid standard. Sample difficult loop, sugar to 3.3 Instruments and equipment
months distilled water to dissolve, and dilute
SH0161-92
instead of ZB BE10-88
crushed, divided into two parts, as a sample, put into a clean container with a concentration of
<5mL pure water, placed overnight.
Gas chromatograph determination, external standard method
2g) appropriate amount of methyl parathion (3.2. 6), with dichloromethane (3. 2. 3) to prepare a concentration of 100gmL standard stock solution 3.3.1 Gas chromatograph: equipped with a flame photometric detector (phosphorus filter). 3. 3. 2 High-speed tissue crushing
3. 3. 3.3.4 All-glass system steaming device.
0~1000
3.3.5 Rotary evaporator or K-I concentrator3.3.6 Separating funnel:
high anhydrous sulfur
3.3.8 Purification column: 350m×8mm (inner diameter) glass chromatography column, filled with glass wool3.4 Determination steps
3.4.1 Raise
10cm high neutral alumina (3.2.1) and 2m thick anhydrous sodium sulfate (3.2.2). Control filling 1
(.2 In this case, sugar is selected in the machine, and the sugar and wet bucket are used for single pouring. The sodium sulfate column is used to modify the present obstacle, and the dichloroethane extract is collected on the sugar rod, and the 4th art is recorded in the paint shrinkage phase. The sample group is placed in the three-mouse model for hydration and deep shrinkage. The concentrated liquid is transferred to the purification column (3.3.8), and the container is washed with 10mL of dioxymethane (3.2.3) and rinsed with washing liquid. The eluent is collected in the receiving bottle, and the volume is 10mL for gas chromatography determination. 3.4.3.1
1 Chromatographic conditions (can be optimized according to the instrument used) =, chromatographic column: 2m×3mm (inner diameter) glass column, filled with 5%/mm) QF-b. Column temperature: 220℃
e. Inlet temperature: 220℃:www.bzxz.net
d. Detector temperature: 280
e. Carrier gas: high purity nitrogen, purity>99.99%, 880mLz min
f. Hydrogen: 55mLmir
g. Air 10mL V min.
3. 3 2 Spectrum determination
Working solution and sample solution are simultaneously subjected to gas chromatography determination. Use corresponding working
its peak value.
～80 mesh),
estimate the approximate concentration of pesticides in the sample solution, and then take and Note: When the sample solution is directly measured without purification, it is necessary to fill the chromatograph inlet tube with about 5cm long silanized quartz wool.
3.4.4 Blank test
Carry out the reagent blank test according to the above operations. 3.4.5 Calculation of results
Use the chromatographic data processor or calculate according to the following formula to obtain the content. x=hxcx
Where: x-content of methyl parathion, m kg h peak height of pesticide in the sample solution, mm:
-peak height of pesticide in the standard working solution. m.-concentration of pesticide in the standard working solution, mL: m-sample volume, g:
V fixed volume of sample solution, mL
Note: When calculating the results, the blank value must be deducted. Additional remarks
This standard was proposed by the State Import and Export Commodity Inspection Bureau of the People's Republic of China. This standard was drafted by Zhuang Jinshi and Liu Gang.
Import and Export Commodity Inspection Bureau of the People's Republic of China
Shandong Import and Export Commodity Inspection Bureau was responsible for drafting. The closest standard for pesticide concentration in China
When the quartz wool is found to be contaminated, it is necessary to replace the clean stone
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