吹扫捕集-气相色谱-冷原子荧光法测定大闸蟹中的甲基汞含量

建立了吹扫捕集-气相色谱/冷原子荧光测定出口大闸蟹中甲基汞的方法。样品经过硝酸(30 %,V/V)提取,采用乙基化试剂进行衍生将其转化为易挥发的甲基乙基汞,在线吹扫捕集至Tenax管,在高纯氩作载气时加热使Tenax捕集管中各种形态的汞热脱附,进入GC柱分离,在700℃~900℃高温下热解还原为元素汞(Hg_⁰),进入冷原子荧光检测器进行检测。结果表明,在0.0125~25 pg/mL范围内甲基汞的线性关系好,相关系数为1.000,方法的检出限和定量限分别为0.022 μg/kg和0.072 μg/kg。在样品中分别添加10、20、50 μg/kg甲基汞标准品进行加标回收率试验,平均回收率为98.1 % ~ 108.7 %,相对标准偏差为1.2 %~2.5 %(n=6)。该法具有操作简单、快速、灵敏度高等优点,对出口大闸蟹的品质及安全评价起到一定指导作用。     

液相色谱-原子荧光法测定鱼肉中有机汞形态

建立微波辅助萃取-液相色谱-原子荧光(MAE-LC-AFS)测定鱼肉中甲基汞和乙基汞的分析方法。优化了液相色谱流动相、微博辅助萃取技术的提取剂浓度和萃取温度。在0~50μg/L范围内甲基汞和乙基汞的线性关系良好,线性相关系数大于0.999,甲基汞和乙基汞检出限(S/N=3)分别为0.07、0.13μg/L。3种样品在0.25、0.5、1.0 mg/kg 3个加标水平下的平均回收率为甲基汞80.3%~91.4%,乙基汞72.2%~83.3%,相对标准偏差(RSD)分别为2.4%~5.8%、2.3%~5.5%。该法适用于鱼肉中甲基汞和乙基汞的测定。     

LC-AFS法测定新疆阿勒泰狗鱼中的无机汞、甲基汞、乙基汞

建立了液相色谱-原子荧光光谱法测定新疆阿勒泰狗鱼中无机汞、甲基汞、乙基汞的方法。结果表明在20.0~100.0μg/L浓度范围内,无机汞、甲基汞、乙基汞的峰面积与其浓度呈良好的线性关系,检出限分别为0.02,0.005和0.01 mg/kg,加标回收率为88.2%~101.3%,相对标准偏差RSD为1.5%~2.8%(n=6),能够满足新疆阿勒泰狗鱼中无机汞、甲基汞、乙基汞残留量的测定。     

鱼酥制品中甲基汞和乙基汞的检测研究

建立了同时测定鱼酥制品中甲基汞和乙基汞的液相色谱-电感耦合等离子体质谱的分析方法。样品以盐酸为提取液微波辅助萃取,采用5%甲醇+(0.10 mol/L乙酸铵-1 g/L L-半胱氨酸)为流动相,SB-C18柱(150 mm×4.6mm,5μm)进行分离,用电感耦合等离子体质谱仪进行检测,整个检测过程可在1 h内完成。试验优化了液相色谱流动相、微波萃取的萃取时间和温度等条件。在0~50μg/L范围内甲基汞和乙基汞的线性关系良好,线性相关系数大于0.999,甲基汞和乙基汞检出限(S/N=3)分别为0.001 8 mg/kg和0.003 6 mg/kg。样品在3个加标水平下的甲基汞和乙基汞的平均回收率分别为91.0%~98.8%和80.5%~87.6%,相对标准偏差(RSD)分别为2.6%~4.0%,3.3%~4.1%。该方法前处理简便,精密度高,准确性好,适用于鱼酥中甲基汞和乙基汞的测定。     

吹扫捕集-气质联用法测定皮革中富马酸二甲酯

建立了吹扫捕集和气相色谱/质谱仪联用测定皮革中富马酸二甲酯(DMF)残留量的方法。样品经吹扫、捕集及热脱附后,于气相色谱-质谱联用仪测定,外标法定量。DMF的质量浓度与其峰面积在一定的浓度范围内呈线性关系,方法的检出限为4.8μg/kg,标准加入回收率在84.9%～103.7%(n=6)之间,相对标准偏差在3.9%～5.7%。该方法灵敏、简便,可用于皮革中富马酸二甲酯的测定。     

吹扫捕集气相色谱-质谱法测定饮用水中 挥发性有机物

建立饮用水中55种挥发性有机物的吹扫捕集气相色谱质谱分析方法。采用吹扫捕集法对饮用水55种挥发性有机物进行富集,热解吸后导入气相色谱-质谱仪,并选用选择离子模式(SIM)进行检测。其回收率在87.90%~118.03%,其中40种化合物的两个水平回收率均在90%~110.0%范围;相对标准偏差均小于10%;进样量为5 m L时,方法的定量下限(LOQ)范围为0.006μg/L~0.123μg/L(S/N=10)。该方法且具有富集效率高、无试剂再污染等特点,适用饮用水中55种挥发性化合物的分析测定。     

吹扫捕集-气相色谱-质谱联用法测定白酒中氰化物

目的建立一种应用吹扫捕集-气相色谱-质谱联用法测定白酒中氰化物的方法。方法白酒加入氢氧化钠调节pH值(使pH12),在碱性条件下水浴蒸干白酒样品,再加入氯胺T和磷酸,以吹扫捕集-气相色谱-质谱联用法进行测定。结果本方法氰化物线性范围在10~200μg/L内,线性良好,线性方程为y=42563x+24231,相关系数(r)为0.999 2。样品加标量为50、100、150μg/L时,回收率范围在75.8%~92.8%之间,相对标准偏差(RSD)范围为3.1%~7.8%;白酒中氰化物的定量限(LOQ)为50μg/L、检出限(LOD)为15μg/L。结论本文建立的白酒中微量氰化物测定方法操作简便、灵敏度高、结果可靠,适用于实验室对白酒中氰化物的定量检测。     

吹扫捕集-GC/MS法测定织物中39种挥发性有机物

建立了吹扫捕集-气相色谱/质谱联用法测定织物中多种挥发性有机化合物的方法。样品经吹扫、捕集及热脱附后,用气相色谱-质谱联用仪测定,外标法定量。39种挥发性有机化合物的质量浓度与其峰面积在一定的浓度范围内呈线性关系,方法的检出限在4.0~6.1μg/kg,平均回收率在82.7%~107.4%,相对标准偏差在2.9%~8.8%。该方法灵敏、简便,可用于织物中挥发性有机物的测定。     

液相色谱-电感耦合等离子体质谱法测定水产品中的4种形态汞

目的建立一种微波萃取-高效液相色谱分离-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry,HPLC-ICP/MS)测定水产品中无机汞(inorganic me rcury,IMC)、甲基汞(methyl mercury,MMC)、乙基汞(ethyl mercury,EMC)和苯基汞(phenyl mercury,PMC)的方法。方法样品经25%四甲基氢氧化胺微波萃取后,用流动相定容,0.45μm微孔滤膜过滤后备用。样品经反相色谱柱分离,ICP/MS检测。结果4种形态的汞在质量浓度0.5~20 ng/mL的范围内呈线性关系,虾仁样品在0.01、0.02、0.2 mg/kg添加水平下的回收率为61.3%~113.7%;鳕鱼在0.01、0.02、0.5 mg/kg添加水平下回收率为60.8%~109.8%;金枪鱼在0.01、0.02、1.0 mg/kg添加水平下回收率为75.5%~115.9%,日内相对标准偏差小于8%,日间相对标准偏差小于10%;4种形态汞的检出限均为4μg/kg.结论该方法快速、准确、灵敏,适合用于水产品中4种汞形态分析检测。     

测汞仪/高效液相色谱-电感耦合等离子体质谱联 用法测定鱼松中总汞和甲基汞的含量

目的测汞仪和高效液相色谱-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry,HPLC-ICP-MS)测定鱼松中总汞及甲基汞的含量。方法样品粉碎均匀后,无需前处理环节,直接通过测汞仪内置的模块对样品中的总汞进行一站式检测。以L-半胱氨酸-乙酸铵-甲醇-盐酸为提取液,高效液相色谱分离,ICP-MS为检测手段对样品中的甲基汞进行测定。结果在优化的检测条件下,总汞的检出限为0.05μg/kg,甲基汞的检出限为0.001 mg/kg;5种鱼松样品中总汞的加标回收率为80.2%~109.6%,甲基汞的回收率为85.0%~108.5%,样品中总汞和甲基汞的相对标准偏差均小于8.0%。样品中甲基汞在总汞中的含量约为49.3%~82.5%,是汞的主要存在形态。结论该方法操作简便、提取效率高,可实现鱼松样品中总汞和甲基汞的快速测定。     

Total Mercury, Inorganic Mercury and Methyl Mercury Determination in Red Wine

This study deals with the development of a method for total Hg, inorganic Hg and methylmercury (MeHg) determination in red wine by using flow injection-cold vapour generation–inductively coupled plasma mass spectrometry (FI-CVG-ICP-MS) and gas chromatography-ICP-MS (GC-ICP-MS). For Hg speciation analysis, a derivatization step was carried out using a 1% (m/v) sodium tetraphenylborate (NaBPh₄) solution, followed by extraction of Hg species and their quantification by GC-ICP-MS. The main parameters evaluated were the make-up gas flow rate, volume of the NaBPh₄ solution, time for derivatization reaction/analyte extraction and solvent used for Hg species extraction. Accuracy was evaluated by analyte recovery, whereas recoveries ranged from 99% to 104% for Hg(II) and MeHg. The limits of detection (LODs) for Hg(II) and MeHg were 0.77 and 0.80 μg L⁻¹, respectively. Wine from Argentina, Brazil, Chile and Uruguay were analysed. The wine samples were also acid digested for total Hg determination by FI-CVG-ICP-MS. The LOD of the method used for total Hg determination was 0.01 μg L⁻¹. The concentrations of Hg species in red wine measured by GC-ICP-MS were lower than the respective LODs. Only total Hg was detected in the analysed samples, where the highest concentration of Hg found was 0.55 ± 0.02 μg L⁻¹.     

直接测汞仪测定食品中的总汞

目的建立食品中总汞的测定方法。方法对不同类型的食品和膳食样品(主要是谷类、奶粉、鱼类、蔬菜水果等)进行了汞含量的分析测定。采用直接测汞仪,样品无需任何消解,无论固体样品还是液体样品均可用汞原子蒸气在253.65nm处的共振线具有强烈的特征吸收进行测定。结果本方法线性范围:0～1mg/kg,检出限为0.008ng,相关系数(r)优于0.9990,相对标准偏差(RSD)均在5.0%以内。测定美国NIST标准物质牡蛎粉(oyster tissue,NBS1566)、菠菜粉(spinach,NBS1570)和国家标准参考物质鱼肉(GBW10029),测定值均在标准值范围内。采用本方法两次参加FAPAS国际比对,测定结果的Z评分均在0.5之内。结论本方法灵敏度高、简便、快速、准确,便于推广,适用于各类食品中总汞的测定。     

Mercury in Food

Since mercury is ubiquitous, everyone consumes trace amounts. It can be found in all food and water, with higher concentrations in foods grown in areas having higher concentrations of mercury in soil. The short-chain alkyl mercury compounds, methyl, dimethyl and ethyl mercury, are more toxic than elemental mercury, inorganic salts of mercury and the aryl mercury compounds. Since mercury is excreted in feces, sweat and exhaled breath as well as in urine, a daily intake of 1.0 mg per day of elemental mercury or inorganic mercury salts appears safe. The USDL established an allowable level of 0.1 mg elemental mercury vapor or inorganic salts of mercury and 0.01 mg alkyl mercury per cubic meter of air for industrial exposures. The average U.S. diet contains less than 1/50 this amount. Epidemiological studies in several locations of elevated mercury content show no cases of methyl mercury poisoning resulting from fish consumption in the U.S. F&DA does not allow the sale of fish containing more than 0.5 ppm (0.5 mg/kg) of mercury, and the canned tuna industry now includes mercury content as one of their quality specifications. The naturally occurring element, mercury, does not appear to pose a toxic hazard in the food supply of the U.S. and there is no evidence that alkyl mercury formed by microorganisms in nature has led to methyl mercury poisoning; however, this does not imply there is no reason to control the release of elemental mercury and inorganic salts of mercury into the environment from industrial operations. It does indicate the problem has been recognized. Steps have been taken to reduce discharges of elemental mercury and inorganic salts of mercury and to reduce or eliminate use of mercurials in agriculture providing an increasing margin of safety against the possibility of an excessive amount of mercury in any form finding its way into any portion of the U.S. food supply.     

Mercury and methylmercury bioaccessibility in swordfish

Concentrations of mercury (Hg) in swordfish (Xiphias gladius) present a food safety problem for many countries. This study analyses total Hg (t-Hg) concentrations in 27 samples of swordfish marketed in Spain in 2005 and in their bioaccessible fractions (soluble concentration in gastrointestinal medium), obtained after applying an in vitro digestion method. Methylmercury (MeHg) was also determined in the bioaccessible fractions. t-Hg concentrations in the samples were 0.41–2.11 mg kg^?1 wet weight, with a mean of 0.96 ± 0.47 mg kg^?1 wet weight. A total of 37% of the samples exceeded the Hg limit set by Spanish legislation (1.0 mg kg^?1 wet weight). Bioaccessible t-Hg concentrations were 0.17–1.72 mg kg^?1 wet weight (0.63 ± 0.4 mg kg^?1 wet weight), corresponding to 38–83% (64% ± 14%) of t-Hg. Bioaccessible MeHg concentrations, representing 94% of the bioaccessible t-Hg concentrations, were 0.16–1.53 mg kg^?1 wet weight, with a mean of 0.49 ± 0.32 mg kg^?1 wet weight. Children and adults who regularly consume this product in Spain have Hg and MeHg intakes that exceed the tolerable daily intake limits recommended by the Food and Agricultural Organization/World Health Organization (FAO/WHO) and US Environmental Protection Agency (USEPA). These results show the need for recommendations about swordfish consumption by population groups at risk in Spain.     

酵母源金属硫蛋白对慢性汞中毒小鼠氧化损伤的修复作用

探讨具有自主知识产权的两种酵母源金属硫蛋白（metallothionein,MT）亚型（MT-1和MT-2）对慢性汞中毒小鼠氧化损伤的修复作用。实验小鼠经氯化汞染毒,连续灌胃两种酵母源MT及二巯基丙磺酸钠（dimercaptopropansulfonate sodium,DMPS）28 d后测定小鼠体质量、全血汞含量及血清超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活力,丙二醛（malondialdehyde,MDA）含量及机体总抗氧化能力（total antioxidative capacity,T-AOC）。与正常对照组小鼠相比,模型对照组小鼠体质量显著下降（P＜0.05）,灌胃给药28 d后,两种酵母源MT亚型高剂量组小鼠体质量显著升高（P＜0.05）;各给药组小鼠血液、肝脏及肾脏汞含量显著低于模型对照组（P＜0.05）,两种酵母源MT亚型高剂量组的排汞效果显著优于DMPS组（P＜0.05）;各给药组小鼠血清中GSH-Px、SOD活力和MDA水平及总抗氧化能力接近正常对照组小鼠水平（P＞0.05）,其中酵母源MT高剂量组的作用效果最佳,且在改善机体T-AOC方面的效果优于DMPS组（P＜0.05）,酵母源MT-1亚型升高小鼠血清SOD活力和降低血清MDA含量的作用效果明显好于酵母源MT-2亚型。两种酵母源MT对慢性汞中毒小鼠具有良好的氧化损伤保护作用及排汞效果。