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食品安全国家标准 动植物油脂中聚二甲基硅氧烷的测定
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GB 5009.254-2016
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标准编号: GB 5009.254-2016 (GB5009.254-2016)
中文名称: 食品安全国家标准 动植物油脂中聚二甲基硅氧烷的测定
英文名称: National Food Safety Standard -- Determination of dimethylsiloxane in animal and vegetable fats and oils
行业: 国家标准
中标分类: X09
字数估计: 7,743
发布日期: 2016-08-31
实施日期: 2017-03-01
标准依据: 国家卫生和计划生育委员会公告2016年第11号
GB 5009.254-2016: 食品安全国家标准 动植物油脂中聚二甲基硅氧烷的测定
GB 5009.254-2016 英文名称: National Food Safety Standard -- Determination of dimethylsiloxane in animal and vegetable fats and oils
中华人民共和国国家标准
1 范围
本标准规定了动植物油脂中聚二甲基硅氧烷的测定方法。
本标准适用于动植物油脂中聚二甲基硅氧烷的测定。
第一法 电感耦合等离子体原子发射光谱法
5 分析步骤
5.1 试样制备
称取5g(精确到0.01g)试样于25mL容量瓶中,加入15mL航空煤油1#,充分混匀,置于70℃
水浴中超声提取2h,用航空煤油1#定容至刻度。然后全部转移至50mL塑料离心管中,再加入
15mL1.37mol/L盐酸充分混匀,于水浴中静置分层,取上清液10mL于15mL塑料离心管备用,同
时做试剂空白试验。易凝固的油脂应置于70℃水浴中,取出后立即测定。
5.2 仪器参考条件见表A.1。
5.3 标准曲线的制作
将标准系列工作液分别吸入电感耦合等离子体原子发射光谱仪中,测定相应的发射强度,以标准工
作液中聚二甲基硅氧烷的浓度为横坐标,以发射强度值为纵坐标,绘制标准曲线。
5.4 试样溶液的测定
将空白和试样溶液吸入电感耦合等离子体原子发射光谱仪中,测定发射强度值,根据标准曲线得到
待测液中聚二甲基硅氧烷的浓度(μg/mL)。
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15%。
8 其他当试样取5.0g时,方法的检出限为0.3mg/kg,定量限为1.0mg/kg。
第二法 火焰原子吸收光谱法
9 原理试样中的聚二甲基硅氧烷经4-甲基-2-戊酮提取,采用配有一氧化二氮-乙炔系统的火焰原子吸收
光谱仪测定试样提取液中的硅含量,外标法定量。
10 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规定的一级水。
10.1 试剂4-甲基-2-戊酮[(CH3)2CHCH2COCH3]。
10.3 标准溶液的配制
10.3.1 聚二甲基硅氧烷标准储备液(1000μg/mL):准确称取100.0mg聚二甲基硅氧烷于50mL烧杯中,用
4-甲基-2-戊酮溶解转移至100mL容量瓶中,定容至刻度,摇匀。该溶液可在冰箱中4℃保存12个月。
10.3.2 聚二甲基硅氧烷标准工作液:称取4g(精确到0.01g)植物油或动物油或氢化植物油空白油脂
(空白油脂为不含聚二甲基硅氧烷的市售油脂)于10mL容量瓶中,需熔化的置于70℃水浴锅中,加入
2mL~3mL4-甲基-2-戊酮稀释,分别移取0μL、40μL、100μL、200μL、300μL、500μL聚二甲基硅氧
烷标准储备液,用4-甲基-2-戊酮定容至刻度,摇匀。得到以植物油或动物油或氢化植物油为基体的
0μg/mL、4μg/mL、10μg/mL、20μg/mL、30μg/mL、50μg/mL的聚二甲基硅氧烷标准工作液。易
凝固的油脂应置于70℃水浴中,取出后立即测定。
11 仪器与设备
11.1 原子吸收光谱仪:附硅空心阴极灯;一氧化二氮-乙炔气路系统(配加热装置的减压阀);一氧化二氮-乙炔系统专用燃烧头。
11.2 天平:感量为0.1mg。
11.3 水浴锅:带控温装置。
11.4 容量瓶:10mL、100mL。
12 分析步骤
12.1 试样制备
植物油或动物油或氢化植物油:称取4g(精确到0.01g)试样于10mL容量瓶中,需熔化的置于
70℃ 水浴锅中,加入4-甲基-2-戊酮稀释至刻度,摇匀。同时做空白试验。
12.2 仪器参考条件
12.2.1 波长:251.6nm。
12.2.2 光谱通带:0.2nm。
12.2.3 灯电流:10mA。
12.2.4 乙炔流量:4.0L/min。
12.2.5 一氧化二氮流量:6.0L/min。
12.3 标准曲线的制作
将标准系列工作液分别吸入原子吸收光谱仪中,测定相应的吸光度值。以标准工作液中聚二甲基
硅氧烷的浓度为横坐标,以吸光度值为纵坐标,绘制标准曲线。
12.4 试样溶液的测定
将空白及试样溶液吸入原子吸收光谱仪中,测定吸光度值。根据标准曲线得到待测溶液中聚二甲
基硅氧烷的浓度(μg/mL)。
14 精密度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15%。
15 其他
当试样取4.0g时,方法的检出限为0.6mg/kg(植物油)、2.4mg/kg(动物油或氢化植物油);方法
的定量限为2.0mg/kg(植物油)、8.0mg/kg(动物油或氢化植物油)。
附 录 A
仪器参考条件
电感耦合等离子体原子发射光谱仪的参考条件见表A.1。
GB 5009.254-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Standard for Food Safety - Determination of
Polydimethylsiloxane in Animal and Vegetable Fats and Oils
ISSUED ON. AUGUST 31, 2016
IMPLEMENTED ON. MARCH 1, 2017
Issued by. National Health and Family Planning Commission of the
People’s Republic of China
Table of Contents
1 Scope ... 3
Method I Inductively Coupled Plasma Atomic Emission Spectrometry
(ICP-AES) ... 3
2 Principle ... 3
3 Reagents and Materials ... 3
4 Instruments and Equipment ... 4
5 Analytical Procedures ... 4
6 Expression of Analysis Results ... 5
7 Precision ... 6
8 Others ... 6
Method II Flame Atomic Absorption Spectrometry ... 6
9 Principle ... 6
10 Reagents and Materials... 6
11 Instruments and Equipment ... 7
12 Analytical Procedures ... 7
13 Expression of Analysis Results ... 8
14 Precision ... 9
15 Others ... 9
Appendix A Instrument Reference Conditions ... 10
National Standard for Food Safety - Determination of
Polydimethylsiloxane in Animal and Vegetable Fats and Oils
1 Scope
This Standard specifies the method of determining polydimethylsiloxane in animal and
vegetable fats and oils.
This Standard shall be applicable to the determination of polydimethylsiloxane in
animal and vegetable fats and oils.
Method I Inductively Coupled Plasma Atomic
Emission Spectrometry (ICP-AES)
2 Principle
Extract polydimethylsiloxane from 1# aviation kerosene in the sample. Adopt
inductively coupled plasma atomic emission spectrometer to determine the content of
silicon in the sample extract. Adopt the external standard method to quantify the
content.
3 Reagents and Materials
Unless otherwise indicated, the reagents adopted under this method are of analytical
purity. The water is first-grade water as specified in GB/T 6682.
3.1 Reagents
3.1.1 1# Aviation kerosene (or it can be considered as organic solvents that can be
directly injected into inductively coupled plasma atomic emission spectrometer and
dissolve polydimethylsiloxane).
3.1.2 Hydrochloric acid (HCl).
3.1.3 Hydrochloric acid solution (1.37 mol/L). weigh-take 114 mL of hydrochloric acid;
add water to dilute to 1,000 mL.
3.2 Standards
1.37 mol/L hydrochloric acid, and mix it thoroughly. Start static stratification in water
bath, then, take 10 mL of supernatant and reserve it in 15 mL plastic centrifuge tube.
Simultaneously start reagent blank test. Easily solidified grease shall be placed in
water bath at 70°C, and immediately measured after being taken out.
5.2 Instrument Reference Conditions
Please refer to Table A.1.
5.3 Formulation of Standard Curve Lines
Inhale the standard series of working fluid into inductively coupled plasma atomic
emission spectrometer; determine the intensity of emission. Take the density of
polydimethylsiloxane in the standard working fluid as the x-coordinate, and the value
of emission intensity as the y-coordinate. Draw the standard curve line.
5.4 Determination of Sample Solution
Inhale the blank and sample solution into inductively coupled plasma atomic emission
spectrometer; determine the intensity of emission. Obtain the density (μg/mL) of
polydimethylsiloxane in the test solution in accordance with the standard curve line.
The content of polydimethylsiloxane in the sample shall be calculated in accordance
with Formula (1).
Where.
Xi - The content of polydimethylsiloxane in the sample, expressed in (mg/kg);
pi - The density of polydimethylsiloxane in the extracted solution, expressed in
(μg/mL);
po - The density of polydimethylsiloxane in the blank grease solution, expressed in
(μg/mL);
V - The volume of the sample, expressed in (mL);
F - Dilution factor;
1000 - Conversion factor.
10.3.2 Standard working fluid of polydimethylsiloxane. weigh-take 4 g (accurate to
0.01 g) of vegetable oil or animal oil or hydrate vegetable oil blank grease (blank
grease is a kind of grease that doesn’t include polydimethylsiloxane in the market),
then, place it in 10 mL volumetric flask. Place what’s need to be dissolved into water
bath kettle at 70°C; add 2 mL~3 mL of 4-methyl-2-pentanone to dilute. Respectively
transfer and take 0 μL, 40 μL, 100 μL, 200 μL, 300 μL and 500 μL of standard stock
solution of polydimethylsiloxane. Add 4-methyl-2-pentanone to dilute to the constant
and 50 μg/mL of standard working fluid of polydimethylsiloxane based on the
vegetable oil or animal oil or hydrate vegetable oil. Easily solidified grease shall be
placed in water bath at 70°C, and immediately measured after being taken out.
11 Instruments and Equipment
11.1 Atomic absorption spectrometer. silicon-attached hollow cathode lamp; nitrous
oxide-acetylene gas system (pressure reducing valve with heating device);
combustion head exclusive for nitrous oxide-acetylene gas system.
11.2 Balance. division value is 0.1 mg.
11.3 Water bath kettle. with temperature-regulating device.
12 Analytical Procedures
12.1 Preparation of Samples
Vegetable oil or animal oil or hydrate vegetable oil. weigh-take 4 g (accurate to 0.01 g)
and place it in 10 mL volumetric flask. Place what’s need to be dissolved into water
bath kettle at 70°C; add 4-methyl-2-pentanone to dilute to the constant volume, then,
shake it well. Simultaneously start reagent blank test.
12.2 Instrument Reference Conditions
12.2.1 Wavelength. 251.6 nm.
12.2.2 Spectral passband. 0.2 nm.
12.2.4 Acetylene flow. 4.0 L/min.
12.2.5 Nitrous oxide flow. 6.0 L/min.
12.3 Formulation of Standard Curve Lines
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