GB/T 17778-2005 PDF in English
GB/T 17778-2005 (GB/T17778-2005, GBT 17778-2005, GBT17778-2005)
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Determination of d-biotin in premix
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| GB/T 17778-1999 | English | 199 |
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Determination of d-biotin in compound premix
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Standards related to (historical): GB/T 17778-2005
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GB/T 17778-2005: PDF in English (GBT 17778-2005) GB/T 17778-2005
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 65.120
B 46
Replacing GB/T 17778-1999
Determination of d-biotin in premix
ISSUED ON: SEPTEMBER 05, 2005
IMPLEMENTED ON: FEBRUARY 01, 2006
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Method 1 - Spectrophotometry ... 4
4 Method 2 - High performance liquid chromatography (arbitration method) ... 7
Determination of d-biotin in premix
1 Scope
This standard specifies two methods for the determination of d-biotin content in
premixed feed, by spectrophotometer and high performance liquid chromatography.
Method 1 and Method 2, as specified in this standard, are applicable to the
determination of compound premix feed and vitamin premix feed, which has a d-biotin
content greater than 1.0 mg/kg. The concentration range of the extract is 2.0 μg/mL ~
20.0 μg/mL.
2 Normative references
The provisions in following documents become the provisions of this Standard through
reference in this Standard. For the dated references, the subsequent amendments
(excluding corrections) or revisions do not apply to this Standard; however, parties who
reach an agreement based on this Standard are encouraged to study if the latest versions
of these documents are applicable. For undated references, the latest edition of the
referenced document applies.
GB/T 6682 Water for analytical laboratory use - Specification and test methods (neq
ISO 3696:1987)
GB/T 14699.1 Feeding stuffs - Sampling
3 Method 1 - Spectrophotometry
3.1 Principle
Extract the d-biotin in the specimen, through the ethanol solution. The d-biotin and 4-
dimethylaminocinnamaldehyde in the sulfuric acid ethanol solution will form an orange
compound. The color depth, within a certain range, is directly proportional to the d-
biotin content.
3.2 Reagents and materials
Unless otherwise stated, only reagents of confirmed analytical grade are used in the
analysis. The water complies with the provisions of grade-3 water in GB/T 6682.
3.2.1 Absolute ethanol.
3.2.2 Ethanol solution: Mix 90 volumes of ethanol with 10 volumes of water.
3.2.3 Sulfuric acid-ethanol solution: Mix 2 volumes of sulfuric acid with 98 volumes
of absolute ethanol.
3.2.4 4-Dimethylaminocinnamaldehyde absolute ethanol solution: 2 g/L.
3.2.5 d-biotin standard solution
3.2.5.1 Standard stock solution: Accurately weigh 0.1000 g of d-biotin standard
substance. Dissolve it in ethanol solution (3.2.2). Quantitatively transfer it to a 100 mL
volumetric flask. Use ethanol water solution to dilute to the mark. Mix well.1.00 mL of
this solution contains 1.00 mg of d-biotin.
3.2.5.2 Standard working solution: Accurately pipette 1.00 mL of d-biotin standard
stock solution (3.2.5.1) into a 50 mL volumetric flask. Add ethanol solution, to dilute
to the mark. Mix well.1.00 mL of this solution contains 20.0 μg of d-biotin,
3.3 Instruments and equipment
3.3.1 Spectrophotometer (with one derivative function).
3.3.2 Ultrasonic extractor for laboratory use.
3.3.3 Analytical balance: Sensitivity 0.0001 g.
3.4 Preparation of specimens
Carry out sampling according to the method specified in GB/T 14699.1. Select a feed
sample of at least 500 g. Reduce it to 100 g by quartering. Grind it. Pass it through a
0.42 mm hole sieve. Mix it. Put it in an airtight container. Save it for later use.
3.5 Analytical procedures
3.5.1 Extraction of specimen solution
Weigh about 2 g of vitamin premix (accurate to 0.0001 g) AND about 5 g ~ 10 g of
compound premix (accurate to 0.000 1 g). Put them in a ground-bottomed flat-bottomed
flask. Add 5.00 mL of water to an ultrasonic extractor (3.3.2) for 20 min. Add 20 mL of
absolute ethanol (3.2.1). Sonicate it for 20 min. Then transfer to a 50 mL volumetric
flask. Use absolute ethanol (3.2.1) to dilute it to the mark. Filter it. Discard the first 10
mL. Use the rest as specimen extract.
3.5.2 Determination
3.5.2.1 Drawing of standard working curve
Accurately pipette 0.00, 1.00, 2,00, 5.00, 10.00 mL of d-biotin standard working
solution (3.2.5.2), into a 25 mL volumetric flask. Add 10.00, 9.00, 8.00, 5.00, 0.00 mL
of ethanol aqueous solution (3.2.2), respectively. Add 1 mL of sulfuric acid-ethanol
solution (3.2.3) and 2 mL of 4-dimethylaminocinnamaldehyde dehydrated ethanol
solution (3.2.4). Shake well. Place at room temperature for 1 h. Use absolute ethanol
solution (3.2.1) to dilute it to the mark. Use a 1.0 cm cuvette, to scan the first derivative
of absorbance by a spectrophotometer, at 500 nm ~ 580 nm. Draw the standard working
curve of the d-biotin content and the peak difference of the first derivative of absorbance,
at 520 nm and 546 nm.
3.5.2.2 Accurately pipette 10.00 mL of 3.5.1 specimen extract, into a 25 mL volumetric
flask. Add 1 mL of sulfuric acid-ethanol solution (3.2.3) and 2 mL of 4-
dimethylaminocinnamon yeast absolute ethanol solution (3.2.4). Shake well. Let it
stand at room temperature for 1 h. Use absolute ethanol (3.2.1) to dilute it to the mark.
Use a 1.0 cm cuvette at 500 nm ~ 580 nm, to measure the peak difference of the first
derivative of absorbance at 520 nm and 546 nm, through a spectrophotometer. Find the
d-biotin content in the specimen extract, from the standard working curve.
3.6 Calculation and presentation of analysis results
3.6.1 The content of d-biotin in the specimen is calculated according to formula (1).
Where:
X - The content of d-biotin in the specimen, in milligrams per kilogram (mg/kg);
m1 - The mass of d-biotin in the specimen extract, as obtained from the standard
curve, in micrograms (μg);
m2 - The specimen mass, in grams (g);
V1 - The volume of the specimen extraction solution, which is pipetted during
specimen determination, in milliliters (mL);
V2 - The total volume of the specimen extract, in milliliters (mL).
3.6.2 For each specimen, take two sets of samples for parallel measurement. Take the
arithmetic mean as the measurement result. Keep three significant figures.
3.7 Precision
3.7.1 Repeatability
The relative deviation of the two independent test results, which are obtained under
repeatability conditions, is specified in Table 1, on the premise that the relative
deviation greater than the specified does not exceed 5%.
standard stock solution in a 50 mL volumetric flask. Use water to dilute it to the
mark.1.00 mL of this solution contains 20.0 μg of d-biotin.
4.3 Instruments and equipment
4.3.1 Ultrasonic extractor for laboratory use.
4.3.2 High-performance liquid chromatography, which is equipped with ultraviolet or
diode matrix detectors.
4.4 Specimen preparation
Same as spectrophotometry 3.4.
4.5 Analytical procedures
4.5.1 Extraction of specimen solution
Weigh about 2 g of vitamin premixed feed (accurate to 0.0001 g) AND about 5 g of
compound premixed feed (accurate to 0.0001 g). Place them in a 100 mL volumetric
flask (if the premixed feed contains minerals, add 0.1 g of DTPA). Add two-thirds of
the volume of distilled water. Ultrasonically extract it in the ultrasonic extractor (4.3.1)
for 20 min. After cooling, use water to make its volume reach to the mark. Filter it.
Make the filtrate pass through a 0.45 µm filter membrane. Prepare for use.
4.5.2 Determination
4.5.2.1 High performance liquid chromatography conditions
Chromatographic column: A C18 column, which has a length of 250 mm, an inner
diameter of 4.6 mm, a particle size of 5 μm.
Mobile phase: 850 mL trifluoroacetic acid solution (4.2.2) plus 150 mL acetonitrile
(chromatographically pure).
Mobile phase flow rate: 1.0 mL/min.
Injection volume: 20 μL.
Detector: UV or diode matrix detector, which uses a wavelength of 210 nm.
4.5.2.2 Quantitative determination
Adjust the operating parameters of the instrument, according to the instructions of the
high-performance liquid chromatograph. Inject the standard working solution (4.2.3.2)
and the specimen extraction solution (4.5.1), into the chromatographic column, to
obtain the response value of the chromatographic peak area. Take the average value of
the peak area of the standard solution, for quantitative calculation.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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