标准编号:	GB 5009.17-2014
中文名称:	食品安全国家标准 食品中总汞及有机汞的测定
英文名称:	National Food Safety Standard-Determination of total mercury and organic-mercury in food
行业分类:	GB    国家标准
发布机构:	中华人民共和国国家卫生和计划生育委员会
发布日期:	2015-09-21
实施日期:	2016-3-21
标准状态:	superseded
被新标准替代:	GB 5009.17-2021 食品安全国家标准 食品中总汞及有机汞的测定
被替代日期:	2022-2-4
替代旧标准:	GB/T 5009.17-2003 食品中总汞及有机汞的测定
翻译语言:	英文
文件格式:	PDF
中文字符数:	13000 字
翻译价格(元):	240.0
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard supersedes “Determination of Total Mercury and Organic-mercury in Foods” (GB/T 5009.17-2003). There are some significant changes in this standard over GB/T 5009.17-2003: - the name of this standard was revised as "National Food Safety Standard - Determination of Total Mercury and Organic-mercury in Foods"; - dithizone colorimetry for determination of total mercury, gas chromatography and cold-vapor atomic absorption method for determination of organic mercury were deleted; - liquid chromatogram - atomic fluorescence spectrometry (LC-AFS) for determination of methyl mercury was added. Contents Foreword i 1 Scope 1 2 Principles 1 3 Reagents and Materials 1 4 Instruments and Apparatus 2 5 Analytical Procedures 3 6 Calculation (Expression) of Analytic Result 5 7 Precision 5 8 Others 5 9 Principle 6 10 Reagents and Materials 6 11 Instruments and Apparatus 7 12 Analytical Procedures 7 13 Calculation (Expression) of Analytical Result 8 14 Precision 8 15 Others 9 16 Principle 9 17 Reagents and Materials 9 18 Instruments and Apparatus 11 19 Analytical Procedures 11 20 Calculation (Expression) of Analytical Result 12 21 Precision 12 22 Others 13 Appendix A Reference Condition of Microwave Digestion 14 Appendix B Chromatogram 15 National Food Safety Standard Determination of Total Mercury and Organic-mercury in Foods 食品安全国家标准 食品中总汞及有机汞的测定 1 Scope Volume I of this standard specifies method for determination of total mercury in foods. Volume I of this standard is applicable to the determination of total mercury in foods. Volume II of this standard specifies the liquid chromatogram - atomic fluorescence spectrometry (LC-AFS) for determination of methyl mercury content in foods. Volume II of this standard is applicable to the determination of methyl mercury content in foods. Volume I Determination of Total Mercury in Foods Method 1 Atomic Fluorescence Spectrometry 2 Principles After being heated and digested in acid, the mercury in the specimen will be reduced to the atomic mercury by the potassium borohydride (KBH4) or sodium borohydride (NaBH4) in acid medium and is carried into the atomizer by the carrier gas (argon gas), the mercury atoms at ground state will be activated to the super-high energy state with the irradiation of the hollow-cathode lamp of special mercury; when the mercury atoms are deactivated to the ground state and eradiate out the fluorescent of characteristic wavelength, the fluorescence intensity is proportional to the mercury content and shall be quantified by comparing with the standard series solution. 3 Reagents and Materials Note: Unless otherwise specified, reagents used in this method are all super pure, and water is Grade 1 water specified in GB/T 6682. 3.1 Reagents 3.1.1 Nitric acid (HNO3). 3.1.2 Hydrogen peroxide (H2O2). 3.1.3 Sulfuric acid (H2SO4). 3.1.4 Potassium hydroxide (KOH). 3.1.5 Potassium borohydride (KBH4): analytically pure; 3.2 Reagent preparation 3.2.1 Nitric acid solution (1+9): measure 50mL nitric acid, slowly pour it into 450mL water. 3.2.2 Nitric acid solution (5+95): measure 5mL nitric acid and slowly pour it into 95mL water. 3.2.3 Potassium hydroxide solution (5g/L): weigh 5.0g potassium hydroxide and dissolve it in pure water, dilute the solution to 1 000mL and mix it uniformly. 3.2.4 Potassium borohydride solution (5g/L): weigh 5.0g potassium borohydride and dissolve it in 5g/L potassium hydroxide solution, dilute the solution to 1 000mL and mix it uniformly, this reagent is prepared freshly before use. 3.2.5 Nitric acid solution of potassium dichromate (0.5g/L): weigh 0.05g potassium dichromate and dissolve it in 100mL nitric acid solution (5+95). 3.2.6 Nitric acid - perchloric acid mixed solution (5+1): measure 500mL nitric acid and add in 100mL perchloric acid, and mix it uniformly. 3.3 Standard sample Mercuric chloride (HgCl2): purity ≥99%. 3.4 Preparation of standard solution 3.4.1 Standard stock solution of mercury (1.00mg/mL): accurately weigh 0.1354g dried mercuric chloride, dissolve it in the nitric acid solution of potassium dichromate (0.5g/L), transfer the liquid into a 100mL-volumetric flask and dilute it to the scale, mix it uniformly finally. Concentration of this solution is 1.00mg/mL. Being protected from light in 4℃ refrigerator, it may be preserved for 2 years. Or standard solution material approved and awarded with reference material certificate by the nation shall be purchased. 3.4.2 Standard intermediate solution of mercury (10μg/mL): pipet 1.00mL standard stock solution of mercury (1.00mg/mL) to a 100mL-volumetric flask, dilute the solution to the scale with nitric acid solution of potassium dichromate (0.5g/L), mix it uniformly finally. Concentration of this solution is 10μg/mL. Being protected from light in 4℃ refrigerator, it may be preserved for 2 years. 3.4.3 Standard working solution of mercury (50ng/mL): pipet 0.50mL standard intermediate solution of mercury (10μg/mL) to a 100mL-volumetric flask, dilute the solution to the scale with nitric acid solution of potassium dichromate (0.5g/L), mix it uniformly finally. This solution concentration is 50ng/mL, and is prepared freshly before use. 4 Instruments and Apparatus Note: Both the glassware and polytetrafluoroethylene digestion inner tank require to be soaked in nitric acid solution (1+4) for 24h, washed with water repeatedly, and finally washed cleanly with deionized water. 4.1 Atomic fluorescence spectrometer. 4.2 Balance: with sensibility of 0.1mg and 1mg. 4.3 Microwave digestion system. 4.4 Pressure digester. 4.5 Constant-temperature drying oven, (50℃~300℃). 4.6 Temperature control electric hot plate (50℃~200℃). 4.7 Ultrasonic water bath. 5 Analytical Procedures 5.1 Pretreatment of specimen 5.1.1 The specimen shall be protected against contamination during the sampling and preparing process. 5.1.2 After the sundries are removed from such samples as grain and bean, the sample shall be uniformly grinded and put into clean polyethylene bottle; seal and preserve it for standby. 5.1.3 As for such fresh samples as vegetables, fruits, fish, meats and eggs, clean them and dry them in the air, take the homogenate of the edible part and put it into clean polyethylene bottle, seal the bottle and put it into 4℃ refrigerator for standby. 5.2 Specimen digestion 5.2.1 Pressure tank digestion method Weigh 0.2g~1.0g (to the nearest of 0.001g) of solid specimen, 0.5g~2.0g of fresh sample or take 1mL~5mL (to the nearest of 0.001g) of liquid specimen, put it into digestion inner tank, and add into 5mL of nitric acid and soak overnight. Cover the inner cap and screw stainless steel enclosure, put inside constant-temperature drying oven at 140℃~160℃ for 4h~5h, and cool it to room temperature naturally. Then, slowly unscrew the stainless steel enclosure, take out the digestion inner tank, wash the inner cap with a small amount of water, put it on temperature control electric hot plate or in ultrasonic water bath at 80℃ or ultrasonic degas for 2min~5min to force brown gas out. Take out the digestion inner tank, transfer the digestive solution into a 25mL-volumetric flask, wash the inner tank for 3 times with a small amount of water, merge the washing solutions to volumetric flask, scale the volume to the scale and mix it uniformly for standby; Blank test is conducted simultaneously. 5.2.2 Microwave digestion method Weigh solid specimen of 0.2g~0.5g (to the nearest 0.001g), fresh sample of 0.2g~0.8g or liquid specimen of 1mL~3mL, put it to digestion tank, and add into 5mL~8mL nitric acid, cover the cap and place overnight, screw the tank cover, conduct the digestion according to standard operating procedure of the microwave digestion instrument (see Table A.1 of Appendix A for reference condition of digestion). Take out the tank after it being cooled, slowly uncover it, wash the inner cap with a small amount of water, put the digestion tank on temperature control electric hot plate or in ultrasonic water bath at 80℃ or ultrasonic degas for 2min~5min to force brown gas out. Take out the digestion inner tank, transfer the digestive solution into a 25mL-plastic volumetric flask, wash the inner tank for 3 times with a small amount of water, merge the washing solutions to volumetric flask , scale the volume to the scale and mix it uniformly for standby; Blank test is conducted simultaneously.

Foreword i 1 Scope 2 Principles 3 Reagents and Materials 4 Instruments and Apparatus 5 Analytical Procedures 6 Calculation (Expression) of Analytic Result 7 Precision 8 Others 9 Principle 10 Reagents and Materials 11 Instruments and Apparatus 12 Analytical Procedures 13 Calculation (Expression) of Analytical Result 14 Precision 15 Others 16 Principle 17 Reagents and Materials 18 Instruments and Apparatus 19 Analytical Procedures 20 Calculation (Expression) of Analytical Result 21 Precision 22 Others Appendix A Reference Condition of Microwave Digestion Appendix B Chromatogram

食品安全国家标准 食品中总汞及有机汞的测定 1 范围 本标准第一篇规定了食品中总汞的测定方法。 本标准第一篇适用于食品中总汞的测定。 本标准第二篇规定了食品中甲基汞含量测定的液相色谱原子荧光光谱联用方法(LC-AFS)。 本标准第二篇适用于食品中甲基汞含量的测定。 第一篇 食品中总汞的测定 第一法 原子荧光光谱分析法 2 原理 试样经酸加热消解后，在酸性介质中，试样中汞被硼氢化钾或硼氢化钠还原成原子态汞，由载气(氩气)带入原子化器中，在汞空心阴极灯照射下，基态汞原子被激发至高能态，在由高能态回到基态时，发射出特征波长的荧光，其荧光强度与汞含量成正比，与标准系列溶液比较定量。 3试剂和材料 注：除非另有说明，本方法所用试剂均为优级纯，水为GB/T 6682规定的一级水。 3.1 试剂 3.1.1 硝酸(HNO3)。 3.1.2过氧化氢(H2O2)。 3.1.3硫酸(H2SO4)。 3.1.4氢氧化钾(KOH)。 3.1.5硼氢化钾(KBH4)：分析纯。 3.2试剂配制 3.2.1 硝酸溶液(1+9)：量取50 mL硝酸，缓缓加入450 mL水中。 3.2.2 硝酸溶液(5+95)：量取5 mL硝酸，缓缓加入95 mL水中。 3.2.3氢氧化钾溶液(5 g/L)：称取5.0 g氢氧化钾，纯水溶解并定容至1 000 mL，混匀。 3.2.4 硼氢化钾溶液(5 g/L)：称取5.0 g硼氢化钾，用5 g/L的氢氧化钾溶液溶解并定容至1 000 mL，混匀。现用现配。 3.2.5重铬酸钾的硝酸溶液(0.5 g/L)：称取0.05 g重铬酸钾溶于100 mL硝酸溶液(5+95)中。 3.2.6 硝酸-高氯酸混合溶液(5+1)：量取500 mL硝酸，100 mL高氯酸，混匀。 3.3 标准品 氯化汞(HgCl2)：纯度≥99％。 3.4标准溶液配制 3.4.1 汞标准储备液(1.00 mg/mL)：准确称取0.135 4 g经干燥过的氯化汞，用重铬酸钾的硝酸溶液(0.5 g/L)溶解并转移至100 mL容量瓶中，稀释至刻度，混匀。此溶液浓度为1.00 mg/mL。于4℃冰箱中避光保存，可保存2年。或购买经国家认证并授予标准物质证书的标准溶液物质。 3.4.2 汞标准中间液(10 μg/mL)：吸取1.00 mL汞标准储备液(1.00 mg/mL)于100 mL容量瓶中，用重铬酸钾的硝酸溶液(0.5 g/L)稀释至刻度，混匀，此溶液浓度为10 μg/mL。于4℃冰箱中避光保存，可保存2年。 3.4.3 汞标准使用液(50 ng/mL)：吸取0.50 mL汞标准中间液(10 μg/mL)于100 mL容量瓶中，用0.5 g/L重铬酸钾的硝酸溶液稀释至刻度，混匀，此溶液浓度为50 ng/mL，现用现配。 4仪器和设备 注：玻璃器皿及聚四氟乙烯消解内罐均需以硝酸溶液(1+4)浸泡24 h，用水反复冲洗，最后用去离子水冲洗干净。 4.1原子荧光光谱仪。 4.2天平：感量为0.1 mg和1 mg。 4.3微波消解系统。 4.4压力消解器。 4.5恒温干燥箱(50℃～300℃)。 4.6控温电热板(50℃～200℃)。 4.7超声水浴箱。 5分析步骤 5.1试样预处理 5.1.1 在采样和制备过程中，应注意不使试样污染。 5.1.2 粮食、豆类等样品去杂物后粉碎均匀，装入洁净聚乙烯瓶中，密封保存备用。 5.1.3 蔬菜、水果、鱼类、肉类及蛋类等新鲜样品，洗净晾干，取可食部分匀浆，装入洁净聚乙烯瓶中，密封，于4℃冰箱冷藏备用。 5.2 试样消解 5.2.1压力罐消解法 称取固体试样0.2 g～1.0 g(精确到0.001 g)，新鲜样品0.5 g～2.0 g或液体试样吸取1 mL～5 mL称量(精确到0.001 g)，置于消解内罐中，加入5 mL硝酸浸泡过夜。盖好内盖，旋紧不锈钢外套，放入恒温干燥箱，140℃～160℃保持4 h～5 h，在箱内自然冷却至室温，然后缓慢旋松不锈钢外套，将消解内罐取出，用少量水冲洗内盖，放在控温电热板上或超声水浴箱中，于80℃或超声脱气2 min～5 min赶去棕色气体。取出消解内罐，将消化液转移至25 mL容量瓶中，用少量水分3次洗涤内罐，洗涤液合并于容量瓶中并定容至刻度，混匀备用；同时作空白试验。 5.2.2微波消解法 称取固体试样0.2 g～0.5 g(精确到0.001 g)、新鲜样品0.2 g～0.8 g或液体试样1 mL～3 mL于消解罐中，加入5 mL～8 mL硝酸，加盖放置过夜，旋紧罐盖，按照微波消解仪的标准操作步骤进行消解(消解参考条件见附录A表A.1)。冷却后取出，缓慢打开罐盖排气，用少量水冲洗内盖，将消解罐放在控温电热板上或超声水浴箱中，于80℃加热或超声脱气2 min～5 min，赶去棕色气体，取出消解内罐，将消化液转移至25 mL塑料容量瓶中，用少量水分3次洗涤内罐，洗涤液合并于容量瓶中并定容至刻度，混匀备用；同时作空白试验。 5.2.3 回流消解法 5.2.3.1 粮食 称取1.0 g～4.0 g(精确到0.001 g)试样，置于消化装置锥形瓶中，加玻璃珠数粒，加45 mL硝酸、10 mL硫酸，转动锥形瓶防止局部炭化。装上冷凝管后，小火加热，待开始发泡即停止加热，发泡停止后，加热回流2 h。如加热过程中溶液变棕色，再加5 mL硝酸，继续回流2 h，消解到样品完全溶解，一般呈淡黄色或无色，放冷后从冷凝管上端小心加20 mL水，继续加热回流10 min放冷，用适量水冲洗冷凝管，冲洗液并入消化液中，将消化液经玻璃棉过滤于100 mL容量瓶内，用少量水洗涤锥形瓶、滤器，洗涤液并入容量瓶内，加水至刻度，混匀。同时做空白试验。 5.2.3.2植物油及动物油脂 称取1.0 g～3.0 g(精确到0.001 g)试样，置于消化装置锥形瓶中，加玻璃珠数粒，加入7 mL硫酸，小心混匀至溶液颜色变为棕色，然后加40 mL硝酸。以下按5.2.3.1“装上冷凝管后，小火加热……同时做空白试验”步骤操作。 5.2.3.3薯类、豆制品 称取1.0 g～4.0 g(精确到0.001 g)，置于消化装置锥形瓶中，加玻璃珠数粒及30 mL硝酸、5 mL硫酸，转动锥形瓶防止局部炭化。以下按5.2.3.1“装上冷凝管后，小火加热……同时做空白试验”步骤操作。 5.2.3.4 肉、蛋类 称取0.5 g～2.0 g(精确到0.001 g)，置于消化装置锥形瓶中，加玻璃珠数粒及30 mL硝酸、5 mL硫酸、转动锥形瓶防止局部炭化。以下按5.2.3.1“装上冷凝管后，小火加热……同时做空白试验”步骤操作。 5.2.3.5孔及孔制品 称取1.0 g～4.0 g(精确到0.001 g)乳或乳制品，置于消化装置锥形瓶中，加玻璃珠数粒及30 mL硝酸，乳加10 mL硫酸，乳制品加5 mL硫酸，转动锥形瓶防止局部炭化。以下按5.2.3.1“装上冷凝管后，小火加热……同时做空白试验”步骤操作。 5.3 测定 5.3.1 标准曲线制作 分别吸取50 ng/mL汞标准使用液0.00 mL、0.20 mL、0.50 mL、1.00 mL、1.50 mL、2.00 mL、2.50 mL于50 mL容量瓶中，用硝酸溶液(1+9)稀释至刻度，混匀。各自相当于汞浓度为0.00 ng/mL、0.20 ng/mL、0.50 ng/mL、1.00 ng/mL、1.50 ng/mL、2.00 ng/mL、2.50 ng/mL。 5.3.2试样溶液的测定 设定好仪器最佳条件，连续用硝酸溶液(1+9)进样，待读数稳定之后，转入标准系列测量，绘制标准曲线。转入试样测量，先用硝酸溶液(1+9)进样，使读数基本回零，再分别测定试样空白和试样消化液，每测不同的试样前都应清洗进样器。试样测定结果按式(1)计算。 5.4仪器参考条件 光电倍增管负高压：240 V；汞空心阴极灯电流：30 mA；原子化器温度：300℃；载气流速：500 mL/min；屏蔽气流速：1 000 mL/min。 6分析结果的表述 试样中汞含量按式(1)计算： ………………(1) 式中： X——试样中汞的含量，单位为毫克每千克或毫克每升(mg/kg或mg/L)； c——测定样液中汞含量，单位为纳克每毫升(ng/mL)； c0——空白液中汞含量，单位为纳克每毫升(ng/mL)； V——试样消化液定容总体积，单位为毫升(mL)； 1 000——换算系数； m——试样质量，单位为克或毫升(g或mL)。 计算结果保留两位有效数字。 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20％。 8 其他 当样品称样量为0.5 g，定容体积为25 mL时，方法检出限0.003 mg/kg，方法定量限0.010 mg/kg。 第二法 冷原子吸收光谱法 9 原理 汞蒸气对波长253.7 nm的共振线具有强烈的吸收作用。试样经过酸消解或催化酸消解使汞转为离子状态，在强酸性介质中以氯化亚锡还原成元素汞，载气将元素汞吹入汞测定仪，进行冷原子吸收测定，在一定浓度范围其吸收值与汞含量成正比，外标法定量。 10试剂和材料 注：除非另有说明，所用试剂均为优级纯，水为GB/T 6682规定的一级水。 10.1 试剂 10.1.1硝酸(HNO3)。 10.1.2盐酸(HCl)。 10.1.3过氧化氢(H2O2)(30％)。 10.1.4无水氯化钙(CaCl2)：分析纯。 10.1.5高锰酸钾(KMnO4)：分析纯。 10.1.6重铬酸钾(K2Cr2O7)：分析纯。 10.1.7氯化亚锡(SnCl2·2H2O)：分析纯。 10.2试剂配制 10.2.1 高锰酸钾溶液(50 g/L)：称取5.0 g高锰酸钾置于100 mL棕色瓶中，用水溶解并稀释至100 mL。 10.2.2硝酸溶液(5+95)：量取5 mL硝酸，缓缓倒入95 mL水中，混匀。 10.2.3重铬酸钾的硝酸溶液(0.5 g/L)：称取0.05 g重铬酸钾溶于100 mL硝酸溶液(5+95)中。 10.2.4氯化亚锡溶液(100 g/L)：称取10 g氯化亚锡溶于20 mL盐酸中，90℃水浴中加热，轻微振荡，待氯化亚锡溶解成透明状后，冷却，纯水稀释定容至100 mL，加入几粒金属锡，置阴凉、避光处保存。一经发现浑浊应重新配制。 10.2.5硝酸溶液(1+9)：量取50 mL硝酸，缓缓加入450 mL水中。 10.3标准品 氯化汞(HgCl2)：纯度≥99％。 10.4标准溶液配制 10.4.1 汞标准储备液(1.00 mg/mL)：准确称取0.135 4 g干燥过的氯化汞，用重铬酸钾的硝酸溶液(0.5 g/L)溶解并转移至100 mL容量瓶中，定容。此溶液浓度为1.00 mg/mL。于4℃冰箱中避光保存，可保存两年。或购买经国家认证并授予标准物质证书的标准溶液物质。 10.4.2汞标准中间液(10 μg/mL)：吸取1.00 mL汞标准储备液(1.00 mg/mL)于100 mL容量瓶中，用重铬酸钾的硝酸溶液(0.5 g/L)稀释和定容。溶液浓度为10 μg/mL。于4℃冰箱中避光保存，可保存两年。 10.4.3汞标准使用液(50 ng/mL)：吸取0.50 mL汞标准中间液(10 μg/mL)于100 mL容量瓶中，用重铬酸钾的硝酸溶液(0.5 g/L)稀释和定容。此溶液浓度为50 ng/mL，现用现配。