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食品安全国家标准 食品中硼酸的测定
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GB 5009.275-2016
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标准编号: GB 5009.275-2016 (GB5009.275-2016)
中文名称: 食品安全国家标准 食品中硼酸的测定
英文名称: Method for determination of Boric acid in Foods
行业: 国家标准
中标分类: X09
字数估计: 5,538
发布日期: 2016-12-23
实施日期: 2017-06-23
旧标准 (被替代): GB/T 21918-2008
标准依据: National Health and Family Planning Commission Notice No.17 of 2016
GB 5009.275-2016: 食品安全国家标准 食品中硼酸的测定
GB 5009.275-2016 英文名称: Method for determination of Boric acid in Foods
中华人民共和国国家标准
1 范围
本标准规定了食品中硼酸的测定方法。
本标准适用于水产品、肉制品(如肉丸)、豆类、面食类、腐竹、粽子、糕点、酱油、凉粉、凉皮等食品中硼酸的测定。
5 分析步骤
5.1 试样制备
固体样品:称取经高速捣碎机捣碎的样品2g~10g(精确至0.01g)于150mL塑料烧杯中,加
40mL~60mL水混匀,缓慢滴加2mL硫酸,超声10min促进溶解混合。加乙酸锌溶液5mL,亚铁氰
化钾溶液5mL,加水定容至100mL,过滤后作为制备的试样溶液。根据样品含量取1.00mL~
3.00mL制备的试样溶液于25mL塑料试管中,加水至5mL。加硫酸溶液(1+1)1mL,振荡混匀,加
EHD-CHCl3 溶液5.00mL,盖上盖子,涡旋振荡器振摇2min,静置分层,吸取下层的EHD-CHCl3 溶液
并通过ϕ7cm干燥快速滤纸过滤。过滤液作为样品测试液。
液体样品:称取样品2g~10g(精确至0.01g)于150mL塑料烧杯中,加40mL水混匀,加乙酸锌
溶液5mL,亚铁氰化钾溶液5mL,加水定容至100mL,过滤后作为制备的试样溶液。根据样品含量取
1.00mL~3.00mL制备的试样溶液于25mL塑料试管中,加水至5mL,加硫酸溶液(1+1)1mL,振荡
混匀,加EHD-CHCl3 溶液5.00mL,盖上盖子,涡旋振荡器振摇2min,静置分层,吸取下层的EHD-
CHCl3 溶液并通过ϕ7cm干燥快速滤纸过滤。过滤液作为样品测试液。
注:如果萃取过程出现乳化现象,可将萃取液3000r/min离心3min或在测定体系中加入1mL甲醇以避免乳化
或沉淀现象,如加入甲醇应保持加水定容总体积为5mL。
5.2 标准曲线的制作
准确吸取硼酸标准溶液0.00mL、1.00mL、2.00mL、3.00mL、4.00mL、5.00mL于25mL塑料试
管中,各加水至5mL。加硫酸溶液(1+1)1mL,振荡混匀,加EHD-CHCl3 溶液5.00mL,盖上盖子,涡
旋振荡器振摇2min,静置分层,吸取下层的EHD-CHCl3 溶液并通过ϕ7cm干燥快速滤纸过滤。
各取1.00mL过滤液于50mL塑料试管中,依次加入姜黄-冰乙酸溶液1.0mL,硫酸0.5mL,摇
匀,静置30min,加无水乙醇25mL,静置10min,于550nm处1cm比色皿测定吸光度。以标准系列
的硼酸含量(μg)为横坐标,以吸光度为纵坐标绘制标准曲线。
5.3 试样溶液的测定
准确吸取样品测试液1.00mL于50mL塑料试管中,以下操作同5.2中的显色、比色步骤。测定吸
光度值,根据标准曲线得到试样溶液中硼酸的浓度。
7 精密度在重复性条件下获得的两次独立测定结果的绝对差值不得超过算术平均值的10%。
8 其他本方法的检出限为2.50mg/kg,定量限为7.50mg/kg。
GB 5009.275-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Boric Acid in Food
ISSUED ON. DECEMBER 23, 2016
IMPLEMENTED ON. JUNE 23, 2017
Issued by. National Health and Family Planning Commission of PRC;
China Food and Drug Administration.
3. No action is required - Full-copy of this standard will be automatically &
immediately delivered to your EMAIL address in 0~60 minutes.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle ... 4
3 Reagents and Materials ... 4
4 Apparatus ... 5
5 Analytical Procedures ... 6
6 Expression of Analytical Results ... 7
7 Precision ... 7
8 Others ... 7
National Food Safety Standard -
Determination of Boric Acid in Food
1 Scope
This Standard specifies the method for determination of boric acid in food.
This Standard is applicable to the determination of boric acid in the following foods
such as aquatic products, meat products (e.g. meatballs), beans, pasta, dried bean-
curd stick, rice dumplings, cookies, soy sauce, bean jelly, cold noodles, etc.
2 Principle
Rapidly enrich, extract the boric acid in the sample through the ethyl hexanediol-
chloroform solution; remove the effect of the coexisting salt; use the protonated
turmeric mixed through the sulfuric acid and turmeric to react with the boric acid to
generate red product. The color depth of the solution is proportional the amount of
boric acid in the sample; the boric acid content in the sample can be determined
through colorimetry.
3 Reagents and Materials
Unless otherwise is specified, the reagents used in this method is analytically pure;
while the used water is Class-III water stipulated in GB/T 6682.
3.1 Reagents
3.1.1 Sulfuric acid (H2SO4).
3.1.2 Anhydrous ethanol (CH3CH2OH).
3.1.3 Methanol (CH3OH).
3.1.4 Potassium ferrocyanide [K4Fe(CN)6•3H2O].
3.1.5 Zinc acetate [Zn(CH3COO)2•2H2O].
3.1.6 Curcumin.
3.1.7 Glacial acetic acid (CH3COOH).
4.4 Vortex oscillator.
5 Analytical Procedures
5.1 Specimen preparation
Solid sample. take 2g~10g (accurate to 0.01g) of sample mashed by high-speed
grinder into 150mL plastic beaker; add 40mL~60mL of water to mix evenly; slowly
titrate 2mL of sulfuric acid; perform ultrasound for 10min to promote the dissolution and
mixing. Add 5mL of zinc acetate solution; add 5mL of potassium ferrocyanide solution;
add water to make constant volume of 100mL; after filtration, it serves as the prepared
specimen solution. Pipette 1.00mL~3.00mL of prepared specimen solution according
to the sample content into 25mL plastic tube; add water to 5mL. Add 1mL of sulfuric
acid solution (1+1); shake evenly; add 5mL of EHD-CHCl3 solution; cover it; shake for
2min by the vortex oscillator; stand for stratification; pipette the lower-layer of EHD-
CHCl3 solution; filter by Φ7cm drying fast filter paper. The filtrate is used as the sample
test solution.
Liquid sample. take 2g~10g (accurate to 0.01g) of sample into 150mL plastic beaker;
add 40mL of water to mix evenly; add 5mL of zinc acetate solution; add 5mL of
potassium ferrocyanide solution; add water to make constant volume of 100mL; after
filtration, it serves as the prepared specimen solution. Pipette 1.00mL~3.00mL of
prepared specimen solution according to sample content into 25mL plastic tube; add
water to 5mL; add 1mL of sulfuric acid solution (1+1); shake evenly; add 5.00mL of
EHD-CHCl3 solution; cover it; shake for 2min by vortex oscillator; stand for stratification;
pipette the lower-layer EHD-CHCl3 solution; filter by Φ7cm drying fast filter paper. The
filtrate is used as the sample test solution.
be centrifuged for 3min at 3000r/min, or add 1mL of methanol into the measurement system to
avoid emulsification or precipitation phenomenon; for instance, the adding methanol shall keep
the water-adding constant-volume of 5mL.
5.2 Drawing of standard curve
Accurately pipette 0.00mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, 5.00mL of boric acid
standard solution into 25mL plastic tube; separately add water to 5mL. Add 1mL of
sulfuric acid solution (1+1); shake evenly; add 5.00mL of EHD-CHCl3 solution; cover it;
shake for 2min by the vortex oscillator; stand for stratification; pipette the lower-layer
EHD-CHCl3 solution; filter by Φ7cm drying fast filter paper.
1.0mL of turmeric-glacial acetic acid solution; 0.5mL of sulfuric acid; shake evenly;
stand for 30min; add 25mL of anhydrous ethanol; stand for 10min; measure the
absorbance at 550nm by 1cm cuvette. Draw the standard curve with the standard
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