GB 5009.231-2016 English PDF

GB 5009.231-2016: Determination of volatile phenolic compounds residues in fishery products Spectrophotometric method
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GB 5009.231-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Determination of
Volatile Phenol Residues in Aquatic Products
ISSUED ON: AUGUST 31, 2016
IMPLEMENTED ON: MARCH 01, 2017
Issued by: National Health and Family Planning Commission of the PRC
Table of Contents
Foreword ...3
1 Scope ...4
2 Principle ...4
3 Reagents and materials ...4
4 Instruments and apparatuses ...6
5 Analysis steps ...6
6 Description of the analysis result ...7
7 Precision ...8
8 Detection-limit ...8
Appendix A Reference schematic diagram of the water-vapor distilling apparatus ...9
National Food Safety Standard - Determination of
Volatile Phenol Residues in Aquatic Products
1 Scope
This Standard specifies the spectrophotometric method for the determination of
volatile phenol residues in aquatic products.
This Standard applies to the determination of volatile phenol residues in edible parts
of aquatic products.
2 Principle
Use alkaline solution to destroy the structure of the sample; under acidic conditions,
use water vapor to distill off the volatile phenolic compound; in the presence of
potassium ferricyanide, it reacts with 4-aminoantipyrine to form an orange-red
antipyrine dye; use trichloromethane to extract; measure the absorbance quantity at
the wavelength of 460 nm.
3 Reagents and materials
Unless otherwise specified, all the reagents in this method are analytical reagents, the
water is grade-3 water that is specified by GB/T 6682.
3.1 Reagents
3.1.1 Trichloromethane (CHCl3).
3.1.2 Ammonia solution (NH3·H2O).
3.1.3 Sulfuric acid (H2SO4).
3.1.4 Sodium hydroxide (NaOH).
3.1.5 Potassium ferricyanide (K3[Fe(CN)6].
3.1.6 Copper sulfate (CuSO4·5H2O).
3.1.7 Methyl orange (C14H15N3NaO3S).
3.1.8 Ammonium chloride (NH4Cl).
3.4.2 Standard working solution: take an appropriate amount of phenol standard
solution; use phenol-free water to dilute to 1.00 μg of phenol per millimeter; use it
within 2 hours after preparation.
4 Instruments and apparatuses
4.1 Water vapor distiller or 500 mL glass water-vapor distilling apparatus (see
Appendix A).
4.2 Balance: the sensitivity is 0.1mg and 0.01g.
4.3 500 mL (pear-shaped) separatory funnel.
4.4 Magnetic stirrer.
4.5 Spectrophotometer.
4.6 Constant-temperature electric furnace or thermostat electric heating sleeve.
4.7 Tissue masher.
5 Analysis steps
5.1 Sample preparation and storage
Use the tissue masher to homogenate the edible part of the aquatic products; stir the
mixture uniformly; package; seal and refrigerate or freeze to store.
5.2 Sample processing
5.2.1 Distillation extraction
Weigh 10 g ~ 20 g of pretreated sample (accurate to 0.01g, and do a blank test at the
same time) into the beaker; add 75 mL of sodium hydroxide solution; use a magnetic
stirrer to stir for 10 min. Then, add 3 ~ 5 drops of methyl orange solution; use sulfuric
acid solution to adjust the pH ≤ 4 (the solution is orange-red); add 5 mL of copper
sulphate solution; mix; then put it in a water-vapor distiller or a 500 mL distilling flask;
use a small amount of phenol-free water to wash the flask; merge the washing liquid
into a water-vapor distilling apparatus or a distilling flask, and add several glass beads.
Use the glass water-vapor distilling apparatus (or water-vapor distiller) to perform
distillation - the water-vapor distilling apparatus shall be connected well to ensure strict
gas leakage; take a 250 mL conical flask to receive the distillate; distillate at medium
speed for 60 min ~ 90 min; until the distillate is about 240 mL, stop the distillation, and
use 10 mL of phenol-free water to wash the condenser; merge the washing liquid into
the distillate (which remains acidic during the distillation). The distillate shall be
GB 5009.231-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Determination of
Volatile Phenol Residues in Aquatic Products
ISSUED ON: AUGUST 31, 2016
IMPLEMENTED ON: MARCH 01, 2017
Issued by: National Health and Family Planning Commission of the PRC
Table of Contents
Foreword ...3
1 Scope ...4
2 Principle ...4
3 Reagents and materials ...4
4 Instruments and apparatuses ...6
5 Analysis steps ...6
6 Description of the analysis result ...7
7 Precision ...8
8 Detection-limit ...8
Appendix A Reference schematic diagram of the water-vapor distilling apparatus ...9
National Food Safety Standard - Determination of
Volatile Phenol Residues in Aquatic Products
1 Scope
This Standard specifies the spectrophotometric method for the determination of
volatile phenol residues in aquatic products.
This Standard applies to the determination of volatile phenol residues in edible parts
of aquatic products.
2 Principle
Use alkaline solution to destroy the structure of the sample; under acidic conditions,
use water vapor to distill off the volatile phenolic compound; in the presence of
potassium ferricyanide, it reacts with 4-aminoantipyrine to form an orange-red
antipyrine dye; use trichloromethane to extract; measure the absorbance quantity at
the wavelength of 460 nm.
3 Reagents and materials
Unless otherwise specified, all the reagents in this method are analytical reagents, the
water is grade-3 water that is specified by GB/T 6682.
3.1 Reagents
3.1.1 Trichloromethane (CHCl3).
3.1.2 Ammonia solution (NH3·H2O).
3.1.3 Sulfuric acid (H2SO4).
3.1.4 Sodium hydroxide (NaOH).
3.1.5 Potassium ferricyanide (K3[Fe(CN)6].
3.1.6 Copper sulfate (CuSO4·5H2O).
3.1.7 Methyl orange (C14H15N3NaO3S).
3.1.8 Ammonium chloride (NH4Cl).
3.4.2 Standard working solution: take an appropriate amount of phenol standard
solution; use phenol-free water to dilute to 1.00 μg of phenol per millimeter; use it
within 2 hours after preparation.
4 Instruments and apparatuses
4.1 Water vapor distiller or 500 mL glass water-vapor distilling apparatus (see
Appendix A).
4.2 Balance: the sensitivity is 0.1mg and 0.01g.
4.3 500 mL (pear-shaped) separatory funnel.
4.4 Magnetic stirrer.
4.5 Spectrophotometer.
4.6 Constant-temperature electric furnace or thermostat electric heating sleeve.
4.7 Tissue masher.
5 Analysis steps
5.1 Sample preparation and storage
Use the tissue masher to homogenate the edible part of the aquatic products; stir the
mixture uniformly; package; seal and refrigerate or freeze to store.
5.2 Sample processing
5.2.1 Distillation extraction
Weigh 10 g ~ 20 g of pretreated sample (accurate to 0.01g, and do a blank test at the
same time) into the beaker; add 75 mL of sodium hydroxide solution; use a magnetic
stirrer to stir for 10 min. Then, add 3 ~ 5 drops of methyl orange solution; use sulfuric
acid solution to adjust the pH ≤ 4 (the solution is orange-red); add 5 mL of copper
sulphate solution; mix; then put it in a water-vapor distiller or a 500 mL distilling flask;
use a small amount of phenol-free water to wash the flask; merge the washing liquid
into a water-vapor distilling apparatus or a distilling flask, and add several glass beads.
Use the glass water-vapor distilling apparatus (or water-vapor distiller) to perform
distillation - the water-vapor distilling apparatus shall be connected well to ensure strict
gas leakage; take a 250 mL conical flask to receive the distillate; distillate at medium
speed for 60 min ~ 90 min; until the distillate is about 240 mL, stop the distillation, and
use 10 mL of phenol-free water to wash the condenser; merge the washing liquid into
the distillate (which remains acidic during the distillation). The distillate shall be