GB/T 5009.190-2003 Determination of polychlorinated biphenyls in seafood

This standard specifies the method for determining the content of polychlorinated biphenyls (PCBs) in seafood. This standard is applicable to the determination of polychlorinated biphenyls (PCBs) in seafood. GB/T 5009.190-2003 Determination of polychlorinated biphenyls in seafood GB/T5009.190-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.190—2003
Replaces GB/T9675--1988
Determination of polychlorobiphenyls (PCBs) in marine foods
Issued on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implemented on January 1, 2004
GB/T5009.190—2003
This standard replaces GB/T9675—1988 "Determination of polychlorobiphenyls in seafood". Compared with GB/T9675-1988, the main changes of this standard are as follows: the Chinese name of the subject has been modified, and the Chinese name of the standard has been changed to "Determination of polychlorinated biphenyls in seafood", - the structure of the original standard has been modified in accordance with GB/T20001.4-2001 "Standard Preparation Rules Part 4: Chemical Analysis Methods".
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Zhejiang Academy of Medical Sciences. The original standard was first issued in 1988, and this is the first revision. 508
1 Scope
Determination of polychlorinated biphenyls in seafood
This standard specifies the method for determining the content of polychlorinated biphenyls (PCBs) in seafood. This standard is applicable to the determination of polychlorinated biphenyls (PCBs) in seafood. 2 Principle
GB/T5009.190 —2003
In seafood, polynitrogen biphenyl residues are extracted with hexane (or petroleum ether). The extract is purified, separated by silica gel column, concentrated, and its total content is determined by gas chromatograph with electron capture detector. 3 Reagents
3.1 Hexane: analytical grade, redistilled in an all-glass distiller. 3.2 Petroleum ether: analytical grade.
3.3 Concentrated sulfuric acid: high-grade pure.
3.4 ​​Anhydrous sodium sulfate: high-grade pure, calcined at 550℃, stored in a desiccator. 3.5 Silica gel: for chromatography, 60 mesh 100 mesh, heated at 360℃ for 10h~12h, added 3.0% water after cooling, shaken for 2h, and stored in a desiccator.
3.6 Polychlorinated biphenyl standard solution: Accurately weigh 10.0mgPCB and PCBs+ and place them in two 100mL volumetric flasks respectively, and dilute with n-hexane To the mark, mix well. The concentration of the solution is 100μg/mL. Dilute with n-hexane to a standard working solution before use. This working solution contains 0.20μg of PCB and PCBs per ml.
4 Instruments
4.1 100mL Erlenmeyer flask with stopper.
4.2 Graduated centrifuge tube with stopper.
4.3 10mm×150mm glass chromatography column with stopper. 4.4 Centrifuge. | |tt||4.5 Constant temperature water bath.
4.6 KD concentrator. bzxZ.net
Gas chromatograph ECDNi.
5 Analysis steps
5.1 Chromatographic conditions
5.1.1 The chromatographic column is a glass column with an inner diameter of 3 mm and a length of 2 m. 5.1.2 Stationary phase:
a) 2.8% OV-210 + 0.23% OV-17 Chromosor bWAWDMCS80~100 mesh. b) 3%OV-101ChromosorbWAWDMCs80~100 mesh. 5.1.3 Temperature: Column temperature 210℃, detector 250℃, vaporizer 230℃. 5.1.4 Carrier gas: high purity nitrogen (99.99%). 5.2 Sample preparation and extraction
Take 5g of the edible fish sample, add about 20g of anhydrous sodium sulfate and grind it into sand, put it in a stoppered conical flask, add 40mL of hexane, 509
GB/T5009.190—2003
vibrate for 0.5h or soak overnight, filter, and rinse the residue with 10mL of hexane twice each time. Combine the filtrate in a graduated stoppered centrifuge tube, concentrate to 5mL, add 5mL of concentrated sulfuric acid, shake, centrifuge at 3000r/min for 15min, and take out the hexane extract. 5.3 Purification of extract
Take 1ml of hexane extract and place it in a column filled with 2g of silica gel (wet column filling). The upper and lower layers of the silica gel are each filled with 1cm high anhydrous sodium sulfate. Use 7mL of hexane for elution. The flow rate is preferably drop by drop (about 30 drops/min). The eluent is concentrated to 1.0mL and can be used for chromatographic determination. 5.4 Determination
Take the same volume of sample extract and polynitrobiphenyl standard solution and enter the chromatograph under the same chromatographic operating conditions. Use PCB and PCB, the sum of the peak heights of the main peaks for determination. PCB, at least one main peak is used, PCB, at least the sum of three main peaks is used to calculate the low. See peaks 1, 2, 3, and 4 in Figure 1. 1—PCB, main peak,
-PCB, main peak.
Figure 1 PCB, +PCBs standard sample chromatogram
6 Result calculation
Where:
X—the content of polyphenylene oxide in the sample, in milligrams per kilogram (mg/kg), Hr
—the sum of the peaks of polyphenylene oxide in the sample, in millimeters (mm), H,-the sum of the peak heights of polychlorinated biphenyls in the standard working solution, in millimeters (mm); the concentration of polyphenylene oxide in the standard working solution, in micrograms per milliliter (μg/mL); the injection volume (μL) is equivalent to the mass of the sample, in grams (g). Note: The type, mesh size and storage time of silica gel after deactivation have a certain influence on the adsorption effect. Before use, standard polyphenylene oxide should be loaded on the column to test the amount of eluent. The amount of silica gel used depends on the organic oxygen content in the seafood sample to eliminate the interference of organochlorine pesticide DDT. 510
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