高效液相色谱-电感耦合等离子体质谱法测定玩具中可迁移六价铬

在前期工作的基础上,制备了色粉、泡泡水、塑料和涂层等4种代表性六价铬阳性样品,涵盖2009/48/EC玩具新指令涉及的三类玩具材料;考察了实际样品中色谱干扰、三价铬含量、样品基体等因素对六价铬检测的影响,为实际检测工作提供参考;以墨水为实际样品,通过加标回收测试,确定了方法定量限为2μg/kg,可以满足2009/48/EC中六价铬为5μg/kg的限值要求;实验室间比对实验结果表明,方法具有良好的精密度。     

超痕量六价铬分析仪测定模拟唾液迁移玩具中的六价铬

唾液具有较强的离子交换能力,并且合适的pH值也有利于三价铬转化为六价铬,在日常的生活中,婴幼儿玩耍玩具时非常喜欢用嘴去探索新鲜事物,含咬玩具的情况非常常见。而另一方面,唾液对于玩具材料具有良好的迁移出六价铬的能力,但作为人体最常见也是最容易接触到的体液,却没有相关的标准或法规对其迁移六价铬的危害性进行有效的限制,这无疑给玩耍的婴幼儿增加了潜在的风险。针对此情况建立了使用超痕量六价铬分析仪测定模拟唾液迁移玩具材料中六价铬的方法,采用模拟胃液迁移特定元素的迁移模型,即在180 min－1的恒温水浴振荡器中,(37±2)℃恒温避光振荡1 h后,(37±2)℃静置1h,此迁移模型能最大程度的还原婴幼儿将玩具含入口中的过程。测试仪器方面,选择硝酸铵作为流动相,以Prin-Cen ONLY WATER Kit For Cr（Ⅵ） Test Fast column色谱柱作为分析柱,使用紫外可见光检测器进行测定。结果表明,六价铬浓度在0~2μg/L范围内线性关系良好,相关系数能达到1.0000,方法检出限为0.006μg/L,方法定量限为0.019μg/L。选取三种实际样品,在低浓度和高浓度的加标回收率能达到95%~105%之间,在0.5μg/L中等浓度水平下,加标样品的相对标准偏差在3.12%-4.36%之间。选取三种阳性样品使用该方法进行测定,均能检出较大的Cr（Ⅵ）。该方法具有良好的准确度和精密度,能应对常见的样品类型,有着较强的适用性。     

顶空固相微萃取-气相色谱-质谱法测定玩具中可迁移有机锡化合物

建立了顶空固相微萃取结合气相色谱-质谱联用技术测定玩具中10种可迁移有机锡化合物的方法。玩具材料经0.07 mol/L HCl浸泡2 h后,使用醋酸-醋酸钠缓冲溶液将浸泡液的pH值调至4.7,然后加入四乙基硼化钠将浸泡液中的有机锡化合物乙基化,在振荡条件下用100 μ m聚二甲基硅氧烷(PDMS)纤维进行顶空固相微萃取,萃取完成后将纤维插入气相色谱进样口进行热解吸,使用DB-5毛细管柱对10种有机锡化合物进行分离。10种有机锡化合物的检出限为0.5~5 μg/kg。两个加标水平(0.500 μg/L和5.00 μg/L)下的回收率分别为80.7%~118.7%和86.2%~120.5%,RSD均低于15%。应用该方法测定了玩具可触及材料(包括涂层、织物、塑料、木料)中的可迁移有机锡化合物。该方法简便、快速、灵敏度高,不需使用有毒有机溶剂,绿色环保。     

共沉淀法辅助分离-离子色谱与电感耦合等离子体质谱联用测定玩具材料中三价铬及超痕量六价铬

采用0.07 mol/L盐酸萃取样品,取一部分萃取液用电感耦合等离子体质谱法(ICP-MS)测定可迁移总铬含量,另一部分萃取液通过Al(NO3)3共沉淀法去除高含量干扰阳离子后用离子色谱-电感耦合等离子体质谱联用法(IC-ICP-MS)测定六价铬(Cr(Ⅵ))含量,用可迁移总铬量减去Cr(Ⅵ)含量求得Cr(Ⅲ)含量,可迁移总铭及Cr(Ⅵ)的方法定量下限分别达0.01 mg/kg和0.003 mg/kg。选取2009/48/EC玩具新指令涉及的玩具材料进行加标及阳性样品验证,可迁移总铭及Cr(Ⅵ)的加标回收率分别为90.2%~101.5%和96.7%~106.7%,实验室间相对标准偏差分别不高于7.4%和7.9%。方法准确可靠,可实现玩具新指令所涉及的3类玩具材料中Cr(Ⅲ)及Cr(Ⅵ)的检测。     

柱后衍生离子色谱法测定玩具中可迁移Cr(Ⅵ)

建立了离子色谱法测定玩具中可迁移Cr(Ⅵ)的新方法。玩具中的可迁移Cr(Ⅵ)经0.07mol/L的HCl提取后,经过AS7阴离子柱进行分离和富集,再与1,5-二苯卡巴肼(DPC)反应进行衍生,用紫外检测器在530nm处进行检测。该方法对玩具材料中Cr(Ⅵ)的检出限为0.005mg/kg;在0.1~50μg/L范围内呈现良好的线性关系,相关系数r2为0.9997;Cr(Ⅵ)的回收率范围为92.8%~102.4%,相对标准偏差为0.8%~5%。方法的灵敏度高,操作简便,基本能满足玩具新指令对玩具材料中可迁移Cr(Ⅵ)的检测要求。     

玩具油漆涂层中有机锡检测能力验证样品研制及应用分析

制备了用于可迁移有机锡检测能力验证的玩具油漆涂层样品,并开展了相关测定能力验证计划,采用迭代法、四分位法和敏感分析法3种不同统计方法对23家实验室数据进行统计分析,并对不满意结果的原因进行了分析。结果表明所研制样品的均匀性和稳定性良好,能满足能力验证要求。不同统计方法对实验室能力评定结果存在差异,但指定值差异很小,而能力评定标准差差异较大,运用卡方检验能选择出更合理的统计方法。     

高效液相色谱串联质谱法检测橡胶玩具中N-亚硝胺及其前体物

建立了橡胶玩具中N-亚硝胺和N-亚硝胺前体物的迁移量的高效液相色谱-串联质谱(HPLC-MS-MS)的检测方法。样品经甲醇提取,采用ZORBAX Eclipse Plus C18柱,以甲酸-乙腈为流动相,梯度洗脱分离后,串联四极杆质谱多反应监测方式检测。以保留时间和子离子比定性,外标法定量。在优化条件下,该方法12 min即可完成6种待测物分析。各分析物在0.01~10 mg/L范围内线性关系良好,相关系数均大于0.999。方法检出限为0.001 mg/L,低于欧盟2009/48/EC的限量要求。分析物在3个不同水平的加标回收率为79%~96%,RSD<8.2%。方法适用于橡胶玩具中N-亚硝胺类物质的快速确认和定量检测。     

儿童用品中17种欧盟玩具安全新指令限制元素迁移量分析与评估

参照欧盟玩具安全(2009/48/EC号)指令的要求,应用电感耦合等离子体原子发射光谱法(ICP-AES)测定儿童用品材料中17种元素迁移量。样品主要有儿童玩具、童车、学生用品和儿童家具四大类别。共计测试样品337批,测试样品数为1 029个。实验结果表明,部分样品中有铝、钡、镉、铬、铜、铅、锰、锶和锌检出,部分样品中铅、镉迁移量超过欧盟玩具安全新指令限量要求。     

儿童用品中17种欧盟玩具安全新指令限制元素迁移量分析与评估

参照欧盟玩具安全(2009/48/EC号)指令的要求,应用电感耦合等离子体原子发射光谱法(ICP-AES)测定儿童用品材料中17种元素迁移量。样品主要有儿童玩具、童车、学生用品和儿童家具四大类别。共计测试样品337批,测试样品数为1 029个。实验结果表明,部分样品中有铝、钡、镉、铬、铜、铅、锰、锶和锌检出,部分样品中铅、镉迁移量超过欧盟玩具安全新指令限量要求。     

气相色谱-离子阱质谱联用测定玩具中8种酯类致敏性芳香剂

建立了气相色谱-离子阱质谱联用测定玩具中丙烯酸乙酯等8种酯类致敏性芳香剂的方法。对于布绒和贴纸玩具样品,采用丙酮超声提取20 min后过0.45μm滤膜直接进样,对于塑料玩具样品,经相应溶剂提取,离心后,澄清溶液经Envi-carb石墨化碳固相萃取小柱净化,丙酮定容,过0.45μm滤膜后通过30 m HP-5 MS色谱柱分离,质谱进行检测,外标法定量。方法对于不同物质的定量限(LOQ)在0.05～8.0 mg/kg之间,线性范围为0.005～50 mg/L,在3个添加水平的平均回收率在80.2%～105.9%之间,RSD在0.7%～8.9%之间。该方法可用于玩具中丙烯酸乙酯等8种酯类致敏性芳香剂的检测。     

印制电路板中六价铬测定方法的研究进展

阐述了近年来国内外印制电路板中六价铬Cr(Ⅵ)的测定方法,主要包括分光光度法、柱后衍生法、离子色谱-电感耦合等离子体质谱联用(IC-ICP-MS)等方法,未来印制电路板中六价铬的测定方法一定向着新技术联用方向发展。     

Quantification of total chromium and hexavalent chromium in UHT milk by ETAAS

Procedures for the quantification of total chromium and hexavalent chromium in UHT milk samples are presented. Total chromium was determined directly in milk with the addition of a surfactant and a mixture of Pd and Mg as a chemical modifier. For the selective separation of hexavalent chromium, the sample pre-treatment consisted in precipitation of proteins and elution of the supernatant through a Chromabond NH2 column. The metal was eluted with nitric acid. Both total chromium and hexavalent chromium were evaluated by atomic absorption spectrometry with electrothermal atomization using the same instrumental conditions. The detection limits were 0.2 and 0.15 microgram l-1 for total chromium and hexavalent chromium, respectively. The linearity ranges under the optimized conditions were 0.2-20 and 0.15-50 micrograms l-1. For total chromium the precision was 4.9 and 5.7% for the analytical and the over-all procedure, respectively, and for hexavalent chromium 4.3 and 4.9%, respectively. The validation of both procedures was performed by the standard additions method and the recoveries were higher than 93% in all cases. For total chromium, a certified reference material was also used to validate the methodology. The methods were applied to the determination of total chromium and hexavalent chromium in 60 UHT milk samples.     

Determination of hexavalent chromium in traditional Chinese medicines by high‐performance liquid chromatography with inductively coupled plasma mass spectrometry

An analytical method that combined high‐performance liquid chromatography with inductively coupled plasma mass spectrometry has been developed for the determination of hexavalent chromium in traditional Chinese medicines. Hexavalent chromium was extracted using the alkaline solution. The parameters such as the concentration of alkaline and the extraction temperature have been optimized to minimize the interconversion between trivalent chromium and hexavalent chromium. The extracted hexavalent chromium was separated on a weak anion exchange column in isocratic mode, followed by inductively coupled plasma mass spectrometry determination. To obtain a better chromatographic resolution and sensitivity, 75 mM NH₄NO₃ at pH 7 was selected as the mobile phase. The linearity of the proposed method was investigated in the range of 0.2–5.0 μg L^?1 (r² = 0.9999) for hexavalent chromium. The limits of detection and quantitation are 0.1 and 0.3 μg L^?1, respectively. The developed method was successfully applied to the determination of hexavalent chromium in Chloriti lapis and Lumbricus with satisfactory recoveries of 95.8–112.8%.     

Chromium removal technologies

Chromium can exist in different oxidation states (e.g. 0, III, VI). Chromium can be both beneficial and toxic to animals and humans depending on its oxidation state and concentration. At low concentration, Cr(III) is essential for animal and human health. Chromium(VI) compounds are highly soluble, mobile and bioavailable compared to trivalent chromium. Chromium(VI) is dangerous for humans due to its toxicity and carcinogenic properties. The presence of hexavalent chromium in waste water is a potential hazard to aquatic animals and humans. Various methods are adopted for the removal of hexavalent chromium from industrial effluents. Among these different techniques, biosorption is the most promising one. In this process, the various components present in biomaterial reduce the toxic hexavalent chromium to non-toxic trivalent chromium. Algae, fungi and bacteria have biosorption properties, and cell walls are responsible for biosorption of dead biomaterial. But this process removes chromium from waste water very slowly. So for chemical modification of biosorbents, optimization of biosorption parameters is required to increase the effectiveness of this process.     

Studies on the repassivation behavior of aluminum and aluminum alloy exposed to chromate solutions

This study explores the repassivation ability of a scratch in a chromate conversion coating (CCC) on aluminum alloy, AA2024‐T3, and hence evaluates the theory of migration of hexavalent chromium ions from the protected surface of the aluminum alloy to the exposed surface. To confirm that protection was indeed restored by hexavalent chromium ions, the repassivation of a scratch on pure aluminum exposed to a dichromate solution was studied. This forms the simplest subsystem model of the CCC on the alloy in which the CCC is replaced by pure hexavalent chromium and alloy with pure aluminum. Open‐circuit potential measurements, synchrotron infrared microspectroscopy (SIRMS) and secondary ion mass spectroscopy (SIMS) have been used judiciously to evaluate the repassivation behavior. Results indicate that the dichromate ions have high mobility. The slow migration of Cr(VI) ions from the protected surface to the scratch is observed to result in repassivation, as seen from the steady increase in the potential in 0.05 M NaCl solution. The results obtained from SIMS and SIRMS confirm the migration of the oxyanions from the protected region to the metal surface exposed by the scratch. The SIRMS results indicate the formation of an Al(III)–Cr(VI) complex, proposed and shown to be formed in the pits. Copyright © 2003 John Wiley & Sons, Ltd.     

光度法在铬(Ⅵ)测定中的研究进展

论述了2006～2009年光度法在铬（Ⅵ）测定中的研究进展．现今测定铬（Ⅵ）的光度法主要包括吸光光度法、催化动力学光度法、荧光光度法和原子吸收光谱法．近年来,人们开始关注流动注射光度法和共振光散射光谱法．这2种光度法在铬（Ⅵ）的测定分析中克服了传统方法的试剂稳定性差、选择性较差等缺点．具有灵敏度高、选择性好、试剂消耗量少和分析速度快等优点．随着分析方法的改进创新和新技术的应用,铬（Ⅵ）光度分析方法将逐步向高灵敏度、高选择性和自动化方向发展．     

六价铬测定方法的进展

文章阐述了2000-2007年来国内外Cr(Ⅵ)的测定方法,包括分光光度法、原子吸收光谱法、电化学分析法等.引用文献49篇.     

Interferences of three elements in flame photometry Cr-Co-Mn system

The correction methods proposed by two of the authors (F.B-M and J.R-M ), for interferential systems of two or three elements in flame photometry, have been applied to the interferential effects that occur in solutions containing chromium, cobalt and manganese, all three elements being present or combinations of two of them.A comparison has been made of the different systems in aqueous and sulphuric acid solutions, with concentrations which varied between 50 and 500 p.p.m. of cobalt or manganese and between 200 and 2000 p.p.m. of chromium.The correction methods that may be applied to experimental values obtained by flame photometry with these systems have been indicated. A series of examples have also been included in order to show the results obtained with prepared solutions of known concentration and with samples previously analysed by chemical methods.Finally, the possibility of increasing the accuracy of the methods by means of a double correction has been considered.     

Determination of organotin compounds in marine sediments using graphite furnace atomic absorption spectrometry

Organotin compounds, especially tributyltin, began to cause concern 10 years ago due to a high toxicity towards marine organisms. Several methods of analysing organotin compounds in various matrices have already been developed to determine organotin species simultaneously, but these are quite expensive as special equipment and specialized staff are needed. A simple screening method, which determines the organic tin compounds in the sediment, has therefore been developed and validated. The method can easily be implemented in laboratories accustomed to tracelement analyses; the sediment is extracted by a two-phase extraction and the organic extract is analysed using graphite furnace atomic absorption spectrometry (GF AA.) The screening method has been validated using high-pressure liquid chromatography-inductively coupled plasma mass spectrometry (HPLC–ICP MS).     

Sources and toxicity of hexavalent chromium

Chromium exists in oxidation states ranging from ?IV to +VI, inclusively. The compounds exhibit a wide range of geometries including square planar, tetrahedral, octahedral, and various distorted geometries. Ore refining, chemical and refractory processing, cement-producing plants, automobile brake lining, catalytic converters for automobiles, leather tanneries, and chrome pigments contribute to the atmospheric burden of chromium. Hexavalent chromium is known to have 100-fold more toxicity than trivalent chromium, for both acute and chronic exposures because of its high water solubility and mobility, as well as easy reduction. The respiratory tract is the major target organ for hexavalent chromium following the inhalation exposure in humans. Chronic inhalation exposure to hexavalent chromium results in effects on the respiratory tract, with perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and nasal itching and soreness as reported. Chronic human exposure to high levels of hexavalent chromium by inhalation or oral exposure may produce effects on the liver, kidney, gastrointestinal, and immune systems, and possibly the blood. Dermal exposure to hexavalent chromium may cause contact dermatitis, sensitivity, and ulceration of the skin.