9秒发货/有发票 梧三标准英文版 优质技术翻译  数据库收录:159759 最近更新:2020-06-16  
支付宝/对公账号 首页   询价  购买流程  英文样品 公司简介   购物车

GB 5009.275-2016

标准搜索结果: 'GB 5009.275-2016'
标准号码内文价格(元)第2步交付天数标准名称状态
GB 5009.275-2016 英文版 300 购买 现货,9秒内自动发货PDF,有增值税发票。 食品安全国家标准 食品中硼酸的测定 有效

   
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
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
Method for determination of Boric acid in Foods
中华人民共和国国家标准
食品安全国家标准
食品中硼酸的测定
2016-12-23发布
2017-06-23实施
中华人民共和国国家卫生和计划生育委员会
国 家 食 品 药 品 监 督 管 理 总 局 发 布
前言
本标准代替GB/T 21918-2008《食品中硼酸的测定》。
本标准与GB/T 21918-2008相比,主要变化如下:
---标准名称修改为“食品安全国家标准食品中硼酸的测定”;
---删除了第二法 电感耦合等离子体原子发射光谱法和电感耦合等离子体质谱法;
---增加了适用范围;
---增加了定量限;
---修改了检验结果表述。
食品安全国家标准
食品中硼酸的测定
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。
2 原理
通过乙基己二醇-三氯甲烷溶液对样品中的硼酸进行快速的富集、萃取,除去共存盐类的影响,利用
硫酸与姜黄混合生成的质子化姜黄与硼酸反应生成红色产物。溶液颜色的深浅与样品中硼酸含量成正
比,通过比色可以测定样品中硼酸的含量。
3 试剂和材料
除非另有说明,本方法所用试剂均为分析纯,水为GB/T 6682规定的三级水。
3.1 试剂
3.1.1 硫酸(H2SO4)。
3.1.2 无水乙醇(CH3CH2OH)。
3.1.3 甲醇(CH3OH)。
3.1.4 亚铁氰化钾[K4Fe(CN)6·3H2O]。
3.1.5 乙酸锌[Zn(CH3COO)2·2H2O]。
3.1.6 姜黄色素。
3.1.7 冰乙酸(CH3COOH)。
3.1.8 2-乙基-1,3-己二醇[CH3CH2CH2CH(OH)CH(C2H5)CH2OH]。
3.1.9 三氯甲烷(CHCl3)。
3.1.10 硼酸(H3BO3)。
3.2 试剂配制
3.2.1 硫酸溶液(1+1):取等体积的硫酸和水,将硫酸沿烧杯壁缓慢注入水中,并用玻璃棒不断搅拌,
使热量及时散失。
3.2.2 亚铁氰化钾溶液:称取106.0g亚铁氰化钾,用水溶解,并稀释至1000mL。
3.2.3 乙酸锌溶液:称取220.0g乙酸锌,先加30mL冰乙酸溶解,用水稀释至1000mL。
3.2.4 姜黄-冰乙酸溶液:称取姜黄色素0.10g溶于100mL冰乙酸中,此溶液保存于塑料容器中。
3.2.5 2-乙基-1,3-己二醇-三氯甲烷溶液(EHD-CHCl3 溶液):取2-乙基-1,3-己二醇10mL,加三氯甲
烷稀释至100mL,此溶液保存于塑料容器中。
3.3 标准溶液配制
3.3.1 硼酸标准储备液:准确称取在硫酸干燥器中干燥5h以上的硼酸0.5000g,溶于水并定容至
1000mL,保存于塑料容器中。此硼酸标准储备液的浓度为500μg/mL。
3.3.2 硼酸标准溶液:取硼酸标准储备液10.00mL,加水定容至1000mL,保存于塑料容器中。此硼
酸标准溶液的浓度为5μg/mL。所配制溶液于0℃~4℃冰箱中可储存3个月。
4 仪器和设备
注:试验中使用的容器均为塑料容器。
4.1 电子天平:感量为0.01g和0.0001g。
4.2 分光光度计。
4.3 高速捣碎机。
4.4 涡旋振荡器。
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
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。
6 分析结果的表述
试样中硼酸含量按式(1)计算:
X=
C×1000×V1
m×1000×V2
(1)
X ---试样中硼酸的含量,单位为毫克每千克(mg/kg);
C ---由标准曲线得到的试样溶液中的硼酸的浓度,单位为微克(μg);
1000---换算系数;
V1 ---试样定容体积,单位为毫升(mL);
m ---试样的质量,单位为克(g);
V2 ---测定所量取的试样溶液的体积,单位为毫升(mL)。
计算结果保留三位有效数字。
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%。
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
食品安全国家标准 食品中硼酸的测定
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.
How to BUY & immediately GET a full-copy of this standard?
2. Search --> Add to Cart --> Checkout (3-steps);
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
pipette the lower-layer EHD-CHCl3 solution; filter by Φ7cm drying fast filter paper. The
filtrate is used as the sample test solution.
NOTE. if the emulsification appears during the extraction process, the extracting solution can
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
shake for 2min by the vortex oscillator; stand for stratification; pipette the lower-layer
EHD-CHCl3 solution; filter by Φ7cm drying fast filter paper.
Separately take 1.00mL of filtrate and place into 50mL plastic tube; successively add
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
   
宁德梧三商贸有限公司 | 纳税人识别号:91350900MA32WE2Q2X | 营业执照:营业执照证书
点击联络我们 联系电邮郑文锐销售经理: Sales@gb-gbt.cn | Sales@ChineseStandard.net | 电话郑经理: 18059327808 | 增值税普通发票 / 增值税专用发票样品
对公开户银行:中国建设银行古田支行 | 账号:35050168730700000955 | 账户名称:宁德梧三商贸有限公司 | 大额行号(非必须):105403500207 对公银行账号证书
翻译支持:全资母公司新加坡场测亚洲公司(https://www.ChineseStandard.net 卖欧美后再内销)
网站备案许可:闽ICP备19012676号 http://www.beian.miit.gov.cn
隐私   ·  优质产品   ·  退款政策   ·  公平交易   ·  关于我们