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食品安全国家标准 食品中锑的测定
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GB 5009.137-2016
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标准编号: GB 5009.137-2016 (GB5009.137-2016)
中文名称: 食品安全国家标准 食品中锑的测定
英文名称: National food safety standard -- Determination of antimony in foods
行业: 国家标准
中标分类: C53
国际标准分类: 67.040
字数估计: 7,766
发布日期: 2016-12-23
实施日期: 2017-06-23
旧标准 (被替代): GB/T 5009.137-2003
标准依据: National Health and Family Planning Commission Notice No.17 of 2016
发布机构: 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
范围: 本标准规定了食品中锑的氢化物原子荧光光谱测定方法。本标准适用于食品中锑的测定。
GB 5009.137-2016: 食品安全国家标准 食品中锑的测定
GB 5009.137-2016 英文名称: National food safety standard -- Determination of antimony in foods
1 范围
本标准规定了食品中锑的氢化物原子荧光光谱测定方法。
本标准适用于食品中锑的测定。
2 原理
试样经酸加热消解后,在酸性介质中,试样中的锑与硼氢化钠或硼氢化钾反应生成挥发性的锑氢化
物,以氩气为载气,将锑氢化物导入电热石英原子化器中原子化,在锑空心阴极灯照射下,基态锑原子被
激发至高能态,再由高能态回到基态时,发射出特征波长的荧光,其荧光强度与锑含量成正比,根据标准
系列进行定量。
3 试剂和材料
除非另有说明,本方法所用试剂均为优级纯,水为GB/T 6682规定的二级水。
3.1 试剂
3.1.1 硝酸 (HNO3)。
3.1.2 过氧化氢 (H2O2)。
3.1.3 盐酸 (HCl)。
3.1.4 硫酸(H2SO4)。
3.1.5 高氯酸 (HClO4)。
3.1.6 硫脲[(NH2)2CS]:分析纯。
3.1.7 碘化钾(KI):分析纯。
3.1.8 抗坏血酸(C6H8O6):分析纯。
3.1.9 硼氢化钾(KBH4)或硼氢化钠 (NaBH4)。
3.1.10 氢氧化钾(KOH)或氢氧化钠 (NaOH)。
3.2 试剂的配制
3.2.1 硝酸-高氯酸混合酸(10+1):分别量取硝酸500mL与高氯酸50mL,混匀。
3.2.2 盐酸溶液(1+9):量取50mL盐酸,加入到450mL水中,混匀。
3.2.3 硫脲-抗坏血酸溶液:分别称取10g硫脲、10g抗坏血酸,溶于100mL水中,混匀。
3.2.4 硫脲-碘化钾溶液:分别称取2g硫脲、10g碘化钾,溶于100mL水中,混匀。
3.2.5 氢氧化钾溶液(2g/L):称取1g氢氧化钾,溶于500mL水中,混匀,临用现配。该溶液中的氢氧
化钾也可用氢氧化钠代替。
3.2.6 硼氢化钾碱溶液(20g/L):称取10g硼氢化钾,溶于500mL氢氧化钾溶液(2g/L)中,混匀,临
用现配。该溶液中的硼氢化钾也可用等摩尔数的硼氢化钠代替。
3.3 标准品
锑标准溶液:1000mg/L。或其他经国家认证并授予标准物质证书的一定浓度的锑标准溶液。
3.4 标准溶液的配制
3.4.1 锑标准中间液(100mg/L):准确吸取1mL锑标准溶液(1000mg/L)于10mL容量瓶中,加水
定容至刻度,混匀。
3.4.2 锑标准使用液(1.00mg/L):准确吸取1mL锑标准中间液(100mg/L)于100mL容量瓶中,加
水定容至刻度,混匀。
3.4.3 锑标准系列溶液:分别准确吸取锑标准使用液(1.00mg/L)0mL、0.100mL、0.200mL、
0.400mL、1.00mL和2.00mL于100mL容量瓶中,加入少量水稀释后,加入10mL盐酸溶液(1+9)、
10mL硫脲-碘化钾溶液或硫脲-抗坏血酸溶液,加水定容至刻度,混匀。此锑标准系列溶液的质量浓度
为0μg/L、1.00μg/L、2.00μg/L、4.00μg/L、10.0μg/L、20.0μg/L。放置30min后测定。
注:可根据仪器的灵敏度及样品中锑的实际含量确定标准系列溶液中锑元素的质量浓度范围。
4 仪器和设备
注:所有玻璃器皿及四氟乙烯消解内罐均需硝酸溶液(1+5)浸泡过夜,用自来水反复冲洗,最后用水冲洗干净。
4.1 原子荧光光谱仪,配锑空心阴极灯。
4.2 天平:感量为1mg。
4.3 可调式电热板。
4.4 可调式电炉。
4.5 微波消解系统:配聚四氟乙烯消解罐。
4.6 恒温干燥箱。
5 分析步骤
5.1 试样制备
注:在采样和试样制备过程中,应避免污染。
5.1.1 粮食、豆类样品
样品去除杂物后,粉碎,储于塑料瓶中。
5.1.2 蔬菜、水果、鱼类、肉类等水分含量高的样品
样品用水洗净,晾干,取可食部分,制成匀浆,储于塑料瓶中。
5.1.3 饮料、酒、醋、酱油等液体样品
将样品摇匀。
5.2 试样消解
5.2.1 湿法消解
准确称取固体试样0.5g~3g(精确至0.001g)或准确移取液体试样1.00mL~5.00mL,置于
50mL~100mL消化容器中(锥形瓶),加入硝酸-高氯酸混合酸(10+1)5mL~10mL浸泡放置过夜。
次日,置于电热板上加热消解,如消解过程溶液色泽较深,稍冷后补加少量硝酸,继续消解,消解至冒白
烟,消化液呈无色透明或略带黄色,加入20mL水,再继续加热赶酸至0.5mL~1mL止,冷却后用少量
水转入10mL容量瓶中,加入2mL盐酸溶液(1+9),用水定容至刻度。准确吸取试样消化液
5.00mL,加入硫脲-碘化钾溶液或硫脲-抗坏血酸溶液1mL,用水稀释定容至10mL,摇匀,放置30min
后测定。同时做试剂空白试验。
5.2.2 微波消解
准确称取固体试样0.2g~0.8g(精确至0.001g)或准确移取液体试样1.00mL~3.00mL,置于微
波消解罐中,加硝酸5mL、过氧化氢1mL。微波消解程序可以根据仪器型号调至最佳条件,推荐条件
可参见附录A。消解完毕,待消解罐冷却后打开,加入20mL水,加热赶酸至0.5mL~1mL止,用少
量水分三次冲洗消解罐,将溶液转移至10mL容量瓶中,加入2mL盐酸溶液(1+9),用水定容至刻度。
准确吸取试样消化液5.00mL,加入硫脲-碘化钾溶液或硫脲-抗坏血酸溶液1mL,用水稀释定容至
10mL,摇匀,放置30min后测定。同时做试剂空白试验。
5.2.3 压力罐消解
准确称取固体试样0.2g~1g(精确至0.001g)或准确移取液体试样1.00mL~5.00mL,置于聚四
氟乙烯内罐中,加硝酸2mL~4mL浸泡过夜。再补加硝酸2mL~4mL。盖好内盖,旋紧不锈钢外
水,加热赶酸至0.5mL~1mL止,用少量水分三次冲洗消解罐,将溶液转移至10mL容量瓶中,加入
2mL盐酸溶液(1+9),用水定容至刻度。准确吸取试样消化液5.00mL,加入硫脲-碘化钾溶液或硫脲-
抗坏血酸溶液1mL,用水稀释定容至10mL,摇匀,放置30min后测定。同时做试剂空白试验。
5.3 仪器参考条件
调整仪器性能至最佳状态,仪器参考条件:光电倍增管电压,300V;空心阴极灯电流,60mA;原子
化器高度,8mm;载气流速,300mL/min。根据各自仪器性能调至最佳状态。
5.4 标准曲线的制作
设定好仪器最佳条件,将炉温升至所需温度后,稳定20min~30min开始测量。以盐酸溶液(5%)
为载流,硼氢化钾碱溶液(20g/L)为还原剂,连续用标准系列溶液的零管进样,待读数稳定之后,锑标准
相应的荧光值为纵坐标,绘制标准曲线。
注:如有自动进样装置,也可用程序自动稀释来配制标准系列。
5.5 试样溶液测定
在与测定标准溶液系列相同的实验条件下,将空白溶液和试样溶液分别导入仪器,测定荧光值,与
标准系列比较定量。
6 分析结果的表述
试样中锑的含量按式(1)计算。
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20%。
当称样量为0.5g(或0.5mL),定容体积为10mL时,本方法的检出限为0.01mg/kg(或0.01mg/L),
定量限为0.04mg/kg(或0.04mg/L)。
GB 5009.137-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Antimony in Foods
ISSUED ON. DECEMBER 23, 2016
IMPLEMENTED ON. JUNE 23, 2017
Issued by. National Health and Family Planning Commission of the
People’s Republic of China;
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 Application Scope ... 4
2 Principle ... 4
3 Reagents and Materials ... 4
4 Apparatus ... 6
5 Analytical Procedures ... 6
6 Expression of Analytical Results ... 8
7 Precision ... 9
8 Others ... 9
Annex A Temperature Programming of Microwave Digestion ... 10
National Food Safety Standard -
Determination of Antimony in Foods
1 Application Scope
This Standard specifies the hydride atomic fluorescence spectrometric method for the
determination of antimony in foods.
This Standard applies to the determination of antimony in foods.
2 Principle
After the sample is digested through acid and heating, in the acidic medium, antimony
in the sample reacts with sodium borohydride or potassium borohydride to produce
volatile antimony hydride; use argon as the carrier gas to lead antimony hydride into
an electric heating quartz atomizer for atomization; under the exposure to antimony
hollow cathode lamp, the ground-state antimony atom is excited to the upper-state,
and then return to the ground-state from the upper-state; it emits fluorescence of a
characteristic wavelength whose fluorescent strength is in direct proportion to
antimony content; and quantitate in accordance with the standard series.
3 Reagents and Materials
Unless specified otherwise, all reagents used in this method are guaranteed reagents;
and all water is grade-2 water specified in GB/T 6682.
3.1 Reagents
3.1.1 Nitric acid (HNO3).
3.1.2 Hydrogen peroxide (H2O2).
3.1.3 Hydrochloric acid (HCl).
3.1.4 Sulfuric acid (H2SO4).
3.1.5 Perchloric acid (HClO4).
3.1.6 Thiocarbamide [(NH2)2CS]. analytically pure.
3.1.7 Potassium iodide (KI). analytically pure.
3.1.8 Ascorbic acid (C6H8O6). analytically pure.
3.1.9 Potassium borohydride (KBH4) or sodium borohydride (NaBH4).
3.1.10 Potassium hydroxide (KOH) or sodium hydroxide (NaOH).
3.2 Preparation of reagents
3.2.1 Nitric acid-perchloric acid mixed acid (10 + 1). measure 500 ml of nitric acid
and 50 ml of perchloric acid; and mix up.
3.2.2 Hydrochloric acid (1 + 9). measure 50 ml of hydrochloric acid; add into 450 ml
of water; and mix up.
3.2.3 Thiocarbamide-ascorbic acid solution. weigh 10 g of thiocarbamide and 10 g of
ascorbic acid; dissolve into 100 ml of water; and mix up.
3.2.4 Thiocarbamide-potassium iodide solution. weigh 2 g of thiocarbamide and 10
g of potassium iodide; dissolve in 100 ml of water; and mix up.
3.2.5 Potassium hydroxide solution (2 g/l). weigh 1 g of potassium hydroxide;
dissolve in 500 ml of water; mix up; and prepare it immediately before use. Potassium
hydroxide in the solution may be replaced with sodium hydroxide.
3.2.6 Potassium borohydride alkali solution (20 g/l). weigh 10 g of potassium
borohydride; dissolve in 500 ml of potassium hydroxide solution (2 g/l); mix up; and
prepare immediately before preparation. Potassium borohydride in the solution may
also be replaced with sodium borohydride of an equal molar ratio.
3.3 Standard substance
concentration which has been certified by the state and granted the certificate of
standard substance.
3.4 Preparation of standard solutions
3.4.1 Antimony standard intermediate solution (100 mg/l). accurately absorb 1 ml of
antimony standard solution (1 000 mg/l) to pour into a 10 ml volumetric flask; add water
dropwise to volume; and mix up.
3.4.2 Antimony standard working solution (1.00 mg/l). accurately absorb 1 ml of
antimony standard intermediate solution (100 mg/l) to pour into a 100 ml volumetric
flask; add water dropwise to volume; and mix up.
0.400 ml, 1.00 ml and 2.00 ml of antimony standard working solution to pour into 100
ml volumetric flasks respectively; after adding a small amount of water for dilution, add
10 ml of hydrochloric acid solution (1 + 9) and 10 ml of thiocarbamide-potassium iodide
solution or thiocarbamide-ascorbic acid solution; add water dropwise to volume; and
mix up. The mass concentrations of the antimony standard serial solutions are 0 μg/l,
Adjust the instrument to the optimum conditions of performance with the reference
conditions for the instrument. photomultiplier voltage, 300 V; the hollow cathode lamp
current, 60 mA; the atomizer height, 8 mm; the carrier gas flow, 300 ml/min. Adjust to
the optimum conditions in accordance with the performance of each instrument.
Set the optimum conditions of the instrument; raise the furnace temperature to the
required temperature; and start measurement after stabilizing for 20 min ~ 30 min. Use
the hydrochloric acid (5%) as the carrier, potassium borohydride alkali solution (20 g/l)
as the reducer; continuously use the standard serial solutions introduced using a zero
tube; after the readings become stable, lead the antimony standard serial solution into
the instrument from higher concentration to lower concentration; and determine the
fluorescence value. Plot the standard curve using the mass concentration of the
antimony standard serial solutions as the abscissa and the corresponding
fluorescence value as the ordinate.
dilution may also be used for the preparation of standard series.
5.5 Determination of sample solution
Under the same test conditions as those for the determination of the standard solution
series, lead the blank solution and test solution into the instrument respectively;
determine the fluorescence values; and compare with those of the standard series for
quantitation.
6 Expression of Analytical Results
The content of antimony in samples is calculated in accordance with Formula (1).
where,
ρ--the mass concentration of antimony in sample solution, in μg/l;
ρ0--the mass concentration of antimony in blank solution, in in μg/l;
V--the constant volume of sample digestive juice, in ml;
m--the weight or transferred volume of sample, in g or ml;
1 000--the conversion coefficient.
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