This standard specifies the sampling, sample preparation and gas chromatography determination method for the detection of ethoxysilane residues in fruits. This standard is applicable to the determination of ethoxysilane residues in fruits such as apples. The detection limit of this standard is 0.05 mg/kg. GB/T 5009.129-2003 Determination of ethoxyquin residues in fruits GB/T5009.129-2003 Standard download decompression password: www.bzxz.net

CS 67.040
National Standard of the People's Republic of China
GR/T 5009,129-—2003
Substitute GB/【15518—1595
Determinatiun of ethoxyguin residues in fruits
Determinatiun of ethoxyguin residues in fruits2003-08-11Promulgated
Ministry of Standardization of the People's Republic of China
Administrative Committee of Standardization of the People's Republic of China
Implementation on 2004-01-01
GB/T 5009.129-2003
This standard replaces GB/T 1551S—1551 Test method for ethoxyguin residues in fruits. Compared with GR/T15819-1995, the main modifications of this standard are as follows: the Chinese name of the standard is changed to "Determination of residues of ethyl chloramine in fruits" and the structure of the original standard is modified in accordance with GB/T20001.4-2001 Standard Numbering Rules Part 4: Chemical Analysis Methods.
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. Drafting units of this standard: Shanghai Import and Export Inspection Bureau, Hangzhou Lewei Food Factory, Shanghai Shanshan Food Hygiene Inspection Institute, main drafters of this standard: Gui Weikun, Lou Yun, Zhi Yicheng, the original standard was first issued in 1995, this is the second time to order
Determination of ethoxylated residues in fruits
GB/T 5009.129-2003
This standard specifies the sampling, sample preparation and gas chromatography determination method for the detection of ethoxylated residues in fruits and vegetables. This standard is applicable to the determination of ethoxylated residues in fruits such as apples. The limit of this standard is 0.33mg/kg,
2 Sampling and sample preparation
2. 1 Inspection batch
No more than 1 batch is an inspection batch,
the goods in the inspection batch have relevant characteristics, such as packaging, marking, origin, specifications and grades. 2.2 Sample weight (see 1)
Maximum weight of the sample
28-169
251-1500
2.3 Sample preparation
Quantity/characteristics
2.2 The sample is to be opened by the machine. Take at least 50℃ of each sample as the original sample. The total weight of the original sample shall not exceed 4kg: after sealing, mark it and send it to the laboratory immediately. 2.4 Sample preparation
Separate the representative sample, take the edible part and cut it into 1/4 pieces, cut it into 2 pieces, put it in a commercial knitting machine, and make it into a veneer. Divide it into two parts, put it in a clean container, seal it and mark it with the date. 2.5 Sample storage
Store the sample in cold storage for 10-19 days.
And: In the process of sampling and sample preparation, the test sample was prevented from changing to the target and the content changed from time to time. 3 Source Processing bZxz.net
The acetylazoles in the fruit were extracted with n-hexane and then washed with water. Then they were directly determined by gas chromatograph equipped with nitrogen detector. The concentration was determined by using unsaturated fatty acid as internal standard. 4 Samples and Materials
4.1 n-hexane: 53% to 60% of the solution was collected. 4.2 anhydrous sodium sulfate: purified by analysis.
4.3 N,N-hexamethylthiocarbamate (purity 99.0%). 4.4 acetylthiocarbamate, purity 98.0%.
4.5 Preparation of standard solution. Weigh appropriate amount of ethoxycarbon and chloramine standard substances, respectively, and prepare stock solutions with a concentration of 1.0 (g/ml). The stock solution needs to be diluted into a standard working solution with an appropriate concentration, of which the concentration of ethoxycarbon should be 10g/mL or similar to that of chloramine in the sample solution, and the concentration of chloramine should be 2g/mL. Prepare 1 new solution before use!
GB/T5009.129—2003
5 Apparatus and equipment
5.1 Gas chromatograph equipped with nitrogen detector. 5. 2. Vibrator,
5.3 Bottle, 25Gml.,
5.4 Volume 50.00m
5.5 Report to sit and shoot, 10L.
6 Analysis step
6.1 Extraction
Difficult to determine the sample (research.CC name) ten-dimensional shape determination: if about 20 water-free after the removal of the liquid, then add f5ml. n-heptane and 1ml.2R/ml. no rate of enemy internal standard liquid: shake the ball 20min filter, wash with n-heptane, add loss, reduce, adjust to 0 mL of oxygen-free bottle, mix. Pipette 5 mL of the upper hexane extract into a 1 mL centrifuge tube with a solvent holder, add 3 mL of distilled water, and infuse. After the layers are separated, take the upper hexane extract for gas chromatography. 6.2 Analysis
6.2.1 Chromatographic conditions
6.2.1.1 Chromatographic column: 2m1. Inner diameter Amm, filled with a (mass fraction> ()V-t01 divided by ChrnnsnrlhWP (_00 day ~: 120).
6.2.1.2 Chromatography at temperature: 153°C. 6.2.1.3 Inlet temperature: 202°C.
6.2.1.4 Detector temperature: 225°C.
6.2.1.5 Gas: purity 99.99%, flow rate 16 ml./n.inm5.2.1. 6
Air, 140mL/min
Hydrogen: 23mL/min
6. 2. 1. 7
6.2.2 Chromatographic determination
Respectively inject the standard working volume of the above samples into the spectrometer. The retention time of the unexposed peak is about 3.%m, and the retention time of the ethoxylated peak is 5.8min. The peak test: except that the sample is not weighed, the rest are carried out according to the above steps. 6.3 Calculation
Use the chromatographic data to calculate the ethoxylated content in the sample according to the following formula: X-SXAxAXm
Where:
CXAXAXn
The ethoxylated content in the sample is expressed in mg/kg: Standard Standard working liquid concentration, unit is microgram per liter (μg/m3): Standard working liquid concentration of ethoxylates, unit is microgram per liter (μg/m3); ...
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