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食品安全国家标准 食品中锰的测定
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GB 5009.242-2017
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标准编号: GB 5009.242-2017 (GB5009.242-2017)
中文名称: 食品安全国家标准 食品中锰的测定
英文名称: Food safety national standard -- Determination of manganese in food
行业: 国家标准
中标分类: X09
字数估计: 8,896
发布日期: 2017-04-06
实施日期: 2017-10-06
旧标准 (被替代): GB/T 5009.90-2003部分; GB 5413.21-2010部分; GB/T 14609-2008部分; GB/T 23545-2009; GB/T 18932.11-2002部分; GB/T 18932.12-2002部分; NY/T 1653-2008部分
标准依据: State Health and Family Planning Commission Notice No. 5 of 2017
GB 5009.242-2017: 食品安全国家标准 食品中锰的测定
GB 5009.242-2017 英文名称: Food safety national standard -- Determination of manganese in food
中华人民共和国国家标准
1 范围
本标准规定了食品中锰的火焰原子吸收光谱法、电感耦合等离子体发射光谱法和电感耦合等离子
体质谱法三种测定方法。
本标准适用于食品中锰的测定。
第一法 火焰原子吸收光谱法
5 分析步骤
5.1 试样制备
5.1.1 固态样品
5.1.1.1 干样豆类、谷物、菌类、茶叶、干制水果、焙烤食品等低含水量样品,取可食部分,必要时经高速粉碎机粉
碎均匀;对于固体乳制品、蛋白粉、面粉等呈均匀状的粉状样品,摇匀。
5.1.1.2 鲜样蔬菜、水果、水产品等高含水量样品必要时洗净,晾干,取可食部分匀浆均匀;对于肉类、蛋类等样品
取可食部分匀浆均匀。
5.1.1.3 速冻及罐头食品经解冻的速冻食品及罐头样品,取可食部分匀浆均匀。
5.1.2 液态样品软饮料、调味品等样品摇匀。
5.1.3 半固态样品搅拌均匀。
5.2 试样消解
5.2.1 微波消解法
称取0.2g~0.5g(精确至0.001g)试样于微波消解内罐中,含乙醇或二氧化碳的样品先在电热板
上低温加热除去乙醇或二氧化碳,加入5mL~10mL硝酸,加盖放置1h或过夜,旋紧外罐,置于微波
消解仪中进行消解(消解条件参见表A.1)。冷却后取出内罐,置于可调式控温电热板上,于120℃~
140℃赶酸至近干,用水定容至25mL或50mL,混匀备用;同时做空白试验。
5.2.2 压力罐消解法
称取0.3g~1g(精确至0.001g)试样于聚四氟乙烯压力消解内罐中,含乙醇或二氧化碳的样品先
在电热板上低温加热除去乙醇或二氧化碳,加入5mL硝酸,加盖放置1h或过夜,旋紧外罐,置于恒温
干燥箱中进行消解(消解条件参见表A.1)。冷却后取出内罐,置于可调式控温电热板上,于120℃~
140℃赶酸至近干,用水定容至25mL或50mL,混匀备用;同时做空白试验。
5.2.3 湿式消解法
称取0.5g~5g(精确至0.001g)试样于玻璃或聚四氟乙烯消解器皿中,含乙醇或二氧化碳的样品
先在电热板上低温加热除去乙醇或二氧化碳,加入10mL混合酸,加盖放置1h或过夜,置于可调式控
温电热板或电热炉上消解,若变棕黑色,冷却后再加混合酸,直至冒白烟,消化液呈无色透明或略带黄
色,放冷,用水定容至25mL或50mL,混匀备用;同时做空白试验。
5.2.4 干式消解法
称取0.5g~5g(精确至0.001g)试样于坩埚中,在电炉上微火炭化至无烟,置于525℃±25℃马
弗炉中灰化5h~8h,冷却。若灰化不彻底有黑色炭粒,则冷却后滴加少许硝酸湿润,在电热板上干燥
后,移入马弗炉中继续灰化成白色灰烬,冷却至室温后取出,用硝酸溶液溶解,并用水定容至25mL或
50mL,混匀备用;同时做空白试验。
注:婴幼儿配方食品建议选用干式消解法。
5.3 仪器参考条件
优化仪器至最佳状态,主要参考条件:吸收波长279.5nm,狭缝宽度0.2nm,灯电流9mA,燃气流量1.0L/min。
5.4 标准曲线的制作
将标准系列工作液分别注入原子吸收光谱仪中,测定吸光度值,以标准工作液的浓度为横坐标,吸
光度值为纵坐标,绘制标准曲线。
5.5 试样溶液的测定
于测定标准曲线工作液相同的实验条件下,将空白和试样溶液注入原子吸收光谱仪中,测定锰的吸
光值,根据标准曲线得到待测液中锰的浓度。
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 其他以取样量0.5g,定容至25mL计,本方法锰的检出限为0.2mg/kg,定量限为0.5mg/kg。
第二法 电感耦合等离子体发射光谱法见GB 5009.268。
第三法 电感耦合等离子体质谱法见GB 5009.268。
附 录 A
试样消解参考条件
微波消解和压力罐消解参考条件见表A.1。
GB 5009.242-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Manganese in Food
ISSUED ON. APRIL 06, 2017
IMPLEMENTED ON. OCTOBER 06, 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 ... 8
7 Precision ... 8
8 Others ... 8
Appendix A Specimen Digestion Reference Conditions ... 10
Foreword
This Standard replaced the determination parts of magnesium in the following
standards such as GB/T 5009.90-2003 Determination of iron, Magnesium and
Manganese in Foods, GB 5413.21-2010 National Food Safety Standard Determination
of Calcium, Iron, Zinc, Sodium, Potassium, Magnesium, Copper and Manganese in
Foods for Infants and Young Children, Milk and Milk Products, GB/T 14609-2008
Inspection of Grain and Oils - Determination of Copper, Iron, Manganese, Zinc,
Calcium, Magnesium in Cereals and Derived Products by Atomic Absorption and
Flame Spectrophotometry, GB/T 23545-2009 Determination of Manganese in White
Wine - Inductively Coupled Plasma Atomic Emission Spectrometry, GB/T 18932.11-
2002 Method for Determination of Potassium, Phosphorus, Iron, Calcium, Zinc,
Aluminum, Sodium, Magnesium, Boron, Manganese, Copper, Barium, Titanium,
Vanadium, Nickel, Cobalt and Chromium in Honey – Inductively Coupled Plasma
Atomic Emission Spectrometry (ICP-AES), GB/T 18932.12-2002 Method for the
Determination of Potassium, Sodium, Calcium, Magnesium, Zine, Iron, Copper,
Manganese, Chromium, Lead, Cadmium Contents in Honey - Atomic Absorption
Spectrometry, and NY/T 1653-2008 Determination for Mineral Elements In Vegetables,
Fruits and Derived Products by ICP - AES Method.
Compared with the above-mentioned standards, this Standard has the major changes
as follows.
--- Modified the standard name into “National Food Safety Standard – Determination
of Manganese in Food”;
--- Modified the contents in the specimen preparation part;
--- Modified the contents in the specimen digestion part;
--- Modified the inductively coupled plasma emission spectrometry as the second
method, the inductively coupled plasma mass spectrometry as the third method
as the third method.
--- Added the method’s limit of detection and quantification limit;
--- Added the appendix.
National Food Safety Standard -
Determination of Manganese in Food
1 Scope
This Standard specifies three determination methods for manganese in food, namely,
flame atomic absorption spectrometry, inductively coupled plasma emission
spectrometry, and inductively coupled plasma mass spectrometry.
This Standard is applicable to the determination of manganese in food.
The First Method of Flame Atomic Absorption Spectrometry
2 Principle
After the digestion treatment, inject the specimen into the atomic absorption
spectrometer; after flame atomization, the manganese absorbs 279.5nm resonance
line; under certain concentration range, its absorbance value is proportional to the
manganese content; then quantify through comparison with the standard series.
3 Reagents and Materials
Unless otherwise is specified, the reagents used in this method shall be guarantee
reagent; while water used in this method shall be Class-II water stipulated in GB/T
6682.
3.1 Reagents
3.1.2 Perchloric acid (HClO4).
3.2 Reagents preparation
3.2.1 Mixed acid [perchloric acid + nitric acid (1+9)]. take 100mL of perchloric acid;
slowly add 900mL of nitric acid; mix evenly.
3.2.2 Nitric acid solution (1+99). take 10mL of nitric acid; slowly add 990mL of water;
5.2.2 Digestion method of pressure tank
Take 0.3g~1g (accurate to 0.001g) of specimen into the Teflon pressure digestion inner
tank; firstly, heat the sample contained ethanol or carbon dioxide at low temperature
on the electric hot plat to remove the ethanol or carbon dioxide; add 5mL of nitric acid;
temperature drying oven for digestion (the digestion condition can refer to Table A.1).
Take out inner tank after cooling; place on the adjustable temperature-control electric
hot plate; expel acid at 120°C~140°C to near dryness; use water to make constant
volume to 25mL or 50mL; mix evenly for spare-use; meanwhile do the blank test.
5.2.3 Wet digestion method
Take 0.5g~5g (accurate to 0.001g) of specimen into the glass vessel or Teflon digestion
vessel; firstly, heat the sample contained ethanol or carbon dioxide at low temperature
on the electric hot plate to remove the ethanol or carbon dioxide; add 10mL of mixed
acid; cover it to stand for 1h or stay overnight; place it on the adjustable temperature-
black; add mixed acid after cooling till the white smoke appears; the digestion solution
is colorless and transparent or slightly yellow; cool off; use water to make constant
volume to 25mL or 50mL; mix evenly for spare-use; meanwhile do the blank test.
5.2.4 Dry digestion method
Take 0.5g~5g (accurate to 0.001g) of specimen into the crucible; carbonize on the
electric furnace with slight fire to smokeless; place into 525°C±25°C muffle furnace for
ashing 5h~8h; the cool off. If the ashing is not complete and there are black carbon
particles; titrate small amount of nitric acid to moisten after cooling off; after drying on
the electric hot plate; transfer into muffle furnace to continue ashing till white ash
solution; use water to make constant volume to 25mL or 50mL; mix evenly for spare-
use; meanwhile do the blank test.
NOTE. dry digestion method is recommended to be used for the infant formula food.
5.3 Instrument reference conditions
Optimize the instrument to the best conditions; major reference conditions. absorption
wavelength 279.5nm, slit width 0.2mm, lamp current 9mA, gas flow rate 1.0L/min.
5.4 Drawing of standard curve
Separately inject the standard series working solutions into the atomic absorption
spectrometer; measure their absorbance values; draw standard curve with
as ordinate.
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