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This standard replaces GB/T 21911-2008 Determination of Phthalate Esters in Food and SN/T 3147-2012 Determination of Phthalate Esters in Export Food.
The following main changes have been made with respect to GB/T21911-2008 (the previous edition):
——The standard is renamed as "National Food Safety Standard - Determination of Phthalate Esters in Food";
——The two target compounds (diallyl phthalate and diisononyl ortho-phthalate) are added;
——Quantative determination via isotope internal standard method is added as Method I;
——The pretreatment method is modified;
——The detection limit of methods is modified.
National Food Safety Standard
Determination of Phthalate Esters in Food
1 Scope
In this standard, Method I specifies the determination method of content of 16 phthalate esters in foods via gas chromatography-mass spectrometry (GC-MS) and Method II specifies the determination method of content of 18 phthalate esters in foods via gas chromatography-mass spectrometry (GC-MS).
In this standard, Method I is applicable to the determination and confirmation of content of dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), bis(2-methoxyethyl) phthalate (DMEP), bis(4-methyl-2-pentyl) phthalate (BMPP), bis(2-ethoxyethyl) phthalate (DEEP), dipentyl phthalate (DPP), dihexyl phthalate (DHXP), benzyl butyl phthalate (BBP), bis(2-n-butoxyethyl) phthalate (DBEP), dicyclohexyl phthalate (DCHP), bis(2-ethylhexyl) phthalate (DEHP), diphenyl phthalate (DPhP), di-n-octyl phthalate (DNOP) or dinonyl phthalate (DNP) in foods via internal standard method, and Method II is applicable to determination and confirmation of content of dimethyl phthalate (DMP), diethyl phthalate (DEP), diallyl phthalate (DAP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), bis(2-methoxyethyl) phthalate (DMEP), bis(4-methyl-2-pentyl) phthalate (BMPP), bis(2-ethoxyethyl) phthalate (DEEP), dipentyl phthalate (DPP), dihexyl phthalate (DHXP), benzyl butyl phthalate (BBP), bis(2-n-butoxyethyl) phthalate (DBEP), dicyclohexyl phthalate (DCHP), bis(2-ethylhexyl) phthalate (DEHP), diphenyl phthalate (DPhP), di-n-octyl phthalate (DNOP), diisononyl ortho-phthalate (DINP) or dinonyl phthalate (DNP) in foods via external standard method.
Method I Gas Chromatography - Mass Spectrometry:
Isotope Internal Standard Method
2 Principle
Add deuterated phthalate into the specimen as internal standard, and determine the various foods with gas chromatograph - mass spectrometer after they are extracted and purified. Adopt the scan pattern of feature Selective Ion Monitoring (SIM), and carry out the qualitative determination by retention time and abundance ratio of qualitative ion fragment and the quantative determination via isotope internal standard method.
3 Reagents and Materials
Unless otherwise specified, chromatographically pure reagents and Class-II water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 n-hexane (C6H14).
3.1.2 Acetonitrile (C2H3N).
3.1.3 Acetone (CH3COCH3).
3.1.4 Dichloromethane (CH2Cl2).
3.2 Standard product
3.2.1 16 phthalate standard products
As for dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), bis(2-methoxyethyl) phthalate (DMEP), bis(4-methyl-2-pentyl) phthalate (BMPP), bis(2-ethoxyethyl) phthalate (DEEP), diamyl phthalate (DPP), dihexyl phthalate (DHXP), benzyl butyl phthalate (BBP), bis(2-n-butoxyethyl) phthalate (DBEP), dicyclohexyl phthalate (DCHP), bis(2-ethylhexyl) phthalate (DEHP), di-n-ocyl phthalate (DNOP), dinonyl phthalate (DNP) and diphenyl phthalate (DPhP), the concentration of mixed liquid standard products is 1,000 μg/mL; see Annex A for the information and purity of standard products.
3.2.2 16 phthalates containing deuterium isotope internal standard
D4-dimethyl phthalate (D4-DMP), D4-diethyl phthalate (D4-DEP), D4-diisobutyl phthalate (D4-DIBP), D4-dibutyl phthalate (D4-DBP), D4-bis(2-methoxyethyl) phthalate (D4-DMEP), D4-bis(4-methyl-2-pentyl) phthalate (D4-BMPP), D4-bis(2-ethoxyethyl) phthalate (D4-DEEP), D4-diamyl phthalate (D4-DPP), D4-dihexyl phthalate (D4-DHXP), D4-benzyl butyl phthalate (BBP), D4-bis(2-n-butoxyethyl) phthalate (D4-DBEP), D4-dicyclohexyl phthalate (D4-DCHP), D4-bis(2-ethylhexyl) phthalate (D4-DEHP), D4-diphenyl phthalate (D4-DPhP), D4-di-n-ocyl phthalate (D4-DNOP) and D4-dinonyl phthalate (D4-DNP): the purity is greater than 99%.
3.3 Preparation of standard solutions
3.3.1 Standard intermediate solutions of 16 phthalates (10 μg/mL): accurately transfer 1mL of standard phthalates respectively (1,000 μg/mL) into 100mL-volumetric flasks, and accurately dilute the solutions to the scale with n-hexane.
3.3.2 Solutions of 16 phthalates containing deuterium isotope internal standard (100\μg/mL): accurately weigh 0.01g (accurate to 0.0001g) of 16 phthalates containing deuterium isotope internal standard respectively, and put them into 100mL-volumetric flasks, dissolve them and accurately dilute the solutions to the scale with n-hexane.
3.3.3 Standard working solutions of 16 phthalates containing deuterium isotope internal standard (10 μg/mL): accurately transfer 10mL of 16 phthalates containing deuterium isotope internal standard (100 μg/mL) into 100mL-volumetric flasks respectively, add n-hexane and accurately dilute the solution to the scale.
3.3.4 Standard series working solutions of 16 phthalates: accurately pipet 16 phthalate standard intermediate solutions (10μg/mL) and dilute them level by level with n-hexane so as to prepare them into standard series solutions with concentration of 0.00μg/mL, 0.02μg/mL, 0.05μg/mL, 0.10μg/mL, 0.20μg/mL, 0.50μg/mL and 1.00μg/mL respectively, meanwhile add internal standard working solutions (10μg/mL) in such a way that the internal standard concentration is 0.125 μg/mL; prepare immediately before use.
4 Instruments and Apparatus
Note: the to-be-used glass ware shall be cleaned well, rinsed with redistilled water for three times, immersed in acetone for 1h, baked at 200℃ for 2h and cooled to room temperature for subsequent use.
4.1 Gas chromatograph - mass spectrometer (GC-MS).
4.2 Analytical balance: with accuracy of 0.0001 g.
4.3 Nitrogen blowing instrument.
4.4 Vortex oscillator.
4.5 Supersonic generator.
4.6 Centrifuge: with rotation speed ≥4,000r/min.
4.7 Grinder.
4.8 Solid-phase extraction (SPE) device.
4.9 Solid-phase extraction column: glass column with PSA/Silica composite filler (1,000 mg; 6mL).
5 Analysis Steps
5.1 Specimen preparation
5.1.1 Liquid sample: take about 200 mL of sample, mix uniformly and pour it into a ground-glass stoppered flask for subsequent use.
5.1.2 Semisolid and solid samples: respectively take about 200g of samples, crush them and put them into ground-glass stoppered flasks for subsequent use.
5.2 Specimen processing
5.2.1 Liquid specimen
5.2.1.1 Liquid Specimen A: liquid milk, beverage, soy sauce, vinegar, white spirit, honey, etc.
Accurately weigh 1.0g (accurate to 0.0001g) of specimen and put it into a 25mL-ground centrifugal tube with stopper, add 125 μL of isotope internal standard working solution, add 2mL~5mL of distilled water, mix by vortexing, accurately add 10mL of n-hexane, swirl for 1min, fiercely shake for 1 min, carry out ultrasonic extraction for 30 min, centrifuge at 1,000 r/min for 5min, and take the supernatant for GC-MS analysis
5.2.1.2 Liquid Specimen B: vegetable oil, etc.
Mix the liquid fat uniformly, accurately weigh 0.5 g (accurate to 0.0001g) and put into a 10mL-ground centrifugal tube with stopper, add 25 μL of isotope internal standard working solution, add 100 μL of n-hexane and 2mL of acetonitrile in sequence, swirl for 1 min, carry out ultrasonic extraction for 20 min and centrifuge at 4,000 r/min for 5min, and collect the supernatant. Add 2mL of acetonitrile into the residue, whirl for 1 min, and centrifuge at 4,000 r/min for 5min. Add 2mL of acetonitrile to extract once again, merge the 3 portions of supernatant for SPE purification.
5.2.2 Semisolid specimen
5.2.2.1 Semisolid Specimen A: jelly, sweet soybean paste, etc.
Accurately weigh 0.5g (accurate to 0.0001g) of the uniformly mixed specimen and put it into a 25mL-ground centrifugal tube with stopper, add 125 μL of isotope internal standard working solution, add 2mL~5mL of distilled water, mix by vortexing, accurately add 10mL of n-hexane, whirl for 1 min, fiercely shake for 1min, carry out ultrasonic extraction for 30 min and centrifuge at 1,000 r/min for 5min, take the supernatant for GC-MS analysis.
5.2.2.2 Semisolid Specimen B: sesame paste, oily sauce, etc.
Thoroughly crush the sample and mix uniformly, accurately weigh 0.5 g (accurate to 0.0001g) and put into a 10mL-ground centrifugal tube with stopper, add 25 μL of isotope internal standard working solution, add 1mL of n-hexane, whirl for 2min, add 5mL of acetonitrile, whirl for 1 min, carry out ultrasonic extraction for 20 min, centrifuge at 4,000 r/min for 5min and collect the supernatant. Add 5mL of acetonitrile and extract once again, and merge all the supernatant. Blow to dry it with nitrogen at 40℃, add 6mL of acetonitrile, mix by vortexing for SPE purification.
Foreword i
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Apparatus
5 Analysis Steps
6 Expression of Analysis Results
7 Precision
8 Miscellaneous
9 Principle
10 Reagents and Materials
11 Instruments and Apparatus
12 Analysis Steps
13 Expression of Analysis Results
14 Precision
15 Miscellaneous
Annex A Table of Information on Common Phthalate Plasticizers
Annex B Monitored Ion Parameters of Phthalates in Isotope Internal Standard Method
Annex C Total Ion Chromatogram of Phthalate Standard Solutions (Isotope Internal Standard Method)
Annex D Monitored Ion Parameters of Phthalates in External Standard Method
Annex E Total Ion Chromatogram of Phthalate Standard Solutions (External Standard Method)
