GB/T 13082-1991 (GB/T 13082-2021 Newer Version) PDF English
GB/T 13082-1991 (GB/T13082-1991, GBT 13082-1991, GBT13082-1991)
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| GB/T 13082-2021 | English | 170 |
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Determination of cadmium in feeds
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| GB/T 13082-1991 | English | 70 |
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Method for determination of cadmium in feeds
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Newer version: GB/T 13082-2021 Standards related to (historical): GB/T 13082-2021
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GB/T 13082-1991: PDF in English (GBT 13082-1991) GB 13082-1991
GB
NATIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Method for determination of cadmium in feeds
ISSUED ON: JULY 16, 1991
IMPLEMENTED ON: APRIL 01, 1992
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China
Table of Contents
1 Subject Contents and Scope of Application ... 3
2 Principle ... 3
3 Reagents and Solutions ... 3
4 Instruments and Apparatuses ... 4
5 Preparation of Samples ... 4
6 Determination Procedures ... 4
6.1 Sample treatment ... 4
6.2 Drawing standard curve ... 5
6.3 Determination ... 5
7 Determination Results ... 5
7.1 Computing formula ... 5
7.2 Result expression ... 6
7.3 Repeatability ... 6
Additional Explanation: ... 6
Method for determination of cadmium in feeds
1 Subject Contents and Scope of Application
This standard specifies the method for determination of cadmium in feeds.
This standard is applicable to the determination of cadmium in feeds.
2 Principle
Decompose the sample by dry ashing method. Under acid conditions and with the
existence of potassium iodide, cadmium ions and iodine ions form a complex, which is
then extraction-separated by methyl isobutyl ketone. Spray the organic phase on
air-acetylene flame to atomize cadmium. Determine its absorbance in relation to the
characteristic resonance-line 228.8 nm. Obtain the content of cadmium by comparing with
the standard series.
3 Reagents and Solutions
Unless otherwise stated, all reagents used in this standard are analytically pure, and the
water is redistilled water.
3.1 Nitric acid (GB 626), guaranteed.
3.2 Hydrochloric acid (GB 622), guaranteed.
3.3 Potassium iodide solution, 2 mol/L: weigh 332 g of potassium iodide (GB 1272),
dissolve in water, and dilute with water to 1 000 mL.
3.4 Ascorbic acid solution, 5%: weigh 5 g of ascorbic acid (C6H8O6), dissolve in water, and
dilute with water to 100 mL (prepare it before use).
3.5 Hydrochloric acid solution, 1 mol/L: weigh 10 mL of hydrochloric acid (3.2), add 110
mL of water and shake well.
3.6 Methyl isobutyl ketone [CH3COCH2CH(CH3)2, HG 3-1118].
3.7 Cadmium standard stock solution: weigh 0.100 0 g of high purity cadmium metal (Cd,
99.99%), put into a 250 mL Erlenmeyer flask, add 10 mL of 1:1 nitric acid, dissolve
completely by heating on an electric hot plate, dry up, take away and allow to cool down.
Add 20 mL of 1:1 hydrochloric acid and 20 mL of water, dissolve by heating, take away
and allow to cool down. Then, transfer to a 1 000 mL volumetric flask, dilute with water to
the scale and shake well. Each milliliter of this solution is equivalent to 100 μg of
cadmium.
3.8 Cadmium standard intermediate solution: pipette 10 mL of cadmium standard stock
solution (3.7) into a 100 mL volumetric flask, dilute with 1 mol/L hydrochloric acid (3.5) to
the scale and shake well. Each milliliter of this solution is equivalent to 10 μg of cadmium.
3.9 Cadmium standard working solution: pipette 10 mL of cadmium standard intermediate
solution (3.8) into a 100 mL volumetric flask, dilute with 1 mol/L hydrochloric acid (3.5) to
the scale and shake well. Each milliliter of this solution is equivalent to 1 μg of cadmium.
4 Instruments and Apparatuses
4.1 Analytical balance, accuracy of 0.000 1 g.
4.2 Muffle furnace.
4.3 Atomic absorption spectrophotometer.
4.4 Hard beaker, 100 mL.
4.5 Volumetric flask, 50 mL.
4.6 Colorimetric tube with stopper, 25 mL.
4.7 Measuring pipets, 1, 2, 5 and 10 mL
4.8 Transfer pipets, 5, 10, 15 and 20 mL.
5 Preparation of Samples
Collect at least 2 kg of representative feeds sample, divide into about-250 g by quartation,
put through a 1 mm sieve, mix well and seal in an airtight wide-necked sample bottle to
prevent deterioration. Store at low temperature for later use.
6 Determination Procedures
6.1 Sample treatment
Accurately weigh 5~10 g of sample, put into a 100 mL hard beaker (4.4), place in the
Muffle furnace (4.2), and leave the furnace door open slightly. Start from a low
temperature, heat up to 200℃ and hold for 1 h, then heat up to 300℃ and hold for 1 h,
finally heat up to 500℃ and burn for 16 h until the sample becomes white or gray and
does not contain any carbon granules.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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