GB 5009.260-2016 English PDF (GB5009.260-2016)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB 5009.260-2016
Historical versions: GB 5009.260-2016
Preview True-PDF (Reload/Scroll if blank)

GB 5009.260-2016: Determination of sodium copper chlorophyllin in foods -- Spectrophotometric method
GB 5009.260-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Determination of
sodium copper chlorophyll in foodstuffs
ISSUED ON. AUGUST 31, 2016
IMPLEMENTED ON. MARCH 01, 2017
Issued by. National Health and Family Planning Commission of PRC
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Principle ... 4 
3 Reagents and materials ... 4 
4 Apparatus ... 5 
5 Analysis steps ... 6 
6 Expression of analysis results ... 7 
7 Precision ... 7 
8 Other ... 8 
Foreword
This Standard replaces GB/T 23749-2009 “Determination of sodium copper
chlorophyllin in foods - Spectrophotometric method”.
Compared with GB/T 23749-2009, the main deviations in this Standard are as
follows.
- changed the standard name as “National Food Safety Standard -
Determination of sodium copper chlorophyll in foodstuffs”;
- modified the measuring wavelength of GB/T 23749-2009;
- modified the measuring steps of GB/T 23749-2009.
National Food Safety Standard - Determination of
sodium copper chlorophyll in foodstuffs
1 Scope
This Standard specifies the determination methods for sodium copper
chlorophyll in fruit and vegetable juice (pulp) drinks, carbonated drinks, flavored
drinks, blended wine, candies, canned food.
This Standard is applicable to the determination of sodium copper chlorophyll
in fruit and vegetable juice (pulp) drinks, carbonated drinks, flavored drinks,
blended wine, candies, canned food.
2 Principle
Sodium copper chlorophyll in the specimen, under acidic conditions, is
absorbed by polyamide powder, is eluted by desorption solution, is determined
by spectrophotometer, is quantified by the standard curve method.
3 Reagents and materials
Unless otherwise stated, the reagents used in this method are of analytically
pure; the water is grade three water specified in GB/T 6682.
3.1 Reagents and materials
3.1.1 Sodium hydroxide.
3.1.2 Ammonium acetate.
3.1.3 Methanol.
3.1.4 Glacial acetic acid.
3.1.5 Polyamide powder. particle size of 0.150mm ~ 0.180mm.
3.2 Reagent preparation
3.2.1 Sodium hydroxide solution (4 mol/L). weigh 16.0 g of sodium hydroxide,
use water to dissolve and set volume to 100 mL.
3.2.2 Sodium hydroxide solution (0.1 mol/L). weigh 0.40 g of sodium hydroxide,
use water to dissolve and set volume to 100 mL.
3.2.3 Ammonium acetate buffer solution (0.2 mol/L). weigh 7.708 g of
ammonium acetate, use water to dissolve and set volume to 500 mL.
3.2.4 Desorption solution. 0.1 mol/L sodium hydroxide solution + methanol =
1+10 (volume ratio).
3.3 Standard product
Sodium copper chlorophyll, content ≥99.0%.
3.4 Preparation of standard solution
3.4.1 Standard stock solution
Accurately weigh 0.0500 g of sodium copper chlorophyll standard product that
has been dried at 105°C ± 1°C to constant weight and is converted to 100%
mass by its purity. Use water to dissolve and set volume to a 100mL brown
volumetric flask. The concentration of this solution is 500 μg/mL. Prepare it at
the same day when use it. Store it from light.
3.4.2 Standard working solution
Accurately pipette 10 mL of 500 μg/mL standard solution to a 100mL beaker.
Add 30 mL of 0.2 mol/L ammonium acetate solution. Use 4 mol/L sodium
hydroxide solution and glacial acetic acid to adjust pH 5 ~ 6. Add into 3.0 g of
polyamide powder. Completely stir 2min. Place it still from light 5min. Use about
20 mL of distilled water to transfer into G3 sand core funnel for suction-filtration.
Discard the filtrate. Use 75 mL of desorption solution to desorb the pigment in
3 times. Pour about 25 mL of desorption solution each time. Soak 2min. Then
shake 2min. Perform suction-filtration. Use 20 mL of desorption solution to wash
the residual liquid clean in the filter bottle. Collect the filtrate. Use desorption
solution to set volume to 100 mL. Prepare a standard solution with a
concentration of 50 μg/mL. Prepare this solution when it is required.
4 Apparatus
4.1 Spectrophotometer.
4.2 Balance. resolution of 0.0001g.
4.3 G3 sand core funnel.
4.4 Suction-filtration device. vacuum pump, suction-filtration bottle.
4.5 Constant temperature drying oven.
4.6 Small sample mincer.
4.7 Porcelain mortar.
5 Analysis steps
5.1 Specimen preparation
5.1.1 Pretreatment of determination specimen of sodium copper
chlorophyll
5.1.1.1 Pretreatment of beverage, alcohol samples
Well shake the sample. Accurately weigh 5mL ~ 10mL (to the nearest of 0.1 mL)
of sample to a 100mL beaker. Heat in 55°C ~ 60°C water bath for 3min ~ 5min.
Remove alcohol.
5.1.1.2 Pretreatment of canned food sample
Place a representative sample in the mincer to fully mash. Accurately weigh 1g
~ 10g of (to the nearest of 0.001g) well-mixed slurry to a 100mL beaker.
5.1.1.3 Pretreatment of candy sample
Place the sample in the porcelain mortar to finely grinded and well mixed.
Accurately weigh 1g ~ 10g of (to the nearest of 0.001g) sample into a 100mL
beaker.
5.1.2 Post-treatment of testing sample solution
Add 30mL of 0.2 mol/L ammonium acetate solution into a 100mL beaker that
contains testing sample powder or sample slurry. Dissolve and well mix the
sample solution. Use 4 mol/L sodium hydroxide solution and glacial acetic acid
to adjust pH 5 ~ 6. Add into 3.0 g of polyamide powder. Completely stir 2min.
Use about 20mL of 60°C ± 2°C distilled water to transfer the sample solution to
G3 sand core funnel for suction-filtration. Discard the filtrate. Then use 75mL of
desorption solution to desorb the pigment in 3 times. Perform suction-filtration.
And use 20 mL of desorption solution to wash the residual liquid clean in the
filter bottle. Collect the filtrate. Use desorption solution to set volume to 100 mL.
5.2 Apparatus conditions
5.2.1 Measuring wavelength. 405nm.
5.2.2 Cuvette. 1cm.
5.3 Production of standard curve
Respectively take 0mL, 5.0mL, 10mL, 20mL, 30mL, 40mL, 50mL of standard
working solutions into 100mL volumetric flasks. Use desorption solution to dilute
to the scale. Prepare into standard series with concentrations of 0 μg/mL, 5
μg/mL, 10 μg/mL, 20 μg/mL, 30 μg/mL, 40 μg/mL, 50 μg/mL. Take 0 μg/mL
solution as blank. Determine its absorbance value. Draw the standard curve of
which the concentration is the abscissa and the absorbance is the ordinate.
5.4 Determination of specimen solution
Take the sample preparation solution that has been pretreated. Take the 0
μg/mL of the standard curve as blank. Determine its absorbance value. Obtain
the concentration of sodium copper chlorophyll in the sample solution based on
the standard curve.
6 Expression of analysis results
The content of sodium copper chlorophyll in the specimen is calculated
according to formula (1).
where,
X - the content of sodium copper chlorophyll in the specimen, in grams per
kilogram (g/kg) or grams per liter (g/L);
c - the concentration of sodium copper chlorophyll obtained from the standard
curve, in micrograms per milliliter (μg/mL);
V - the set volume of the sample, in milliliters (mL);
m - the sample amount weighed, in grams or milliliters (g or mL).
The calculated results are expressed as the arithmetic mean of two
independent determinations obtained under repetitive conditions. The result
remains three digits after the decimal point.
7 Precision
The absolute difference between two independent determinations obtained
under repeatability conditions sha...