UV-photolysis assisted digestion of food samples for the determination of selenium by electrothermal atomic absorption spectrometry (ETAAS)

An UV-oxidation procedure has been developed to completely digest biological/food samples for the determination of trace levels of selenium. A combined use of UV photolysis and hydrogen peroxide in the presence of an oxidant (HNO₃), results in the complete oxidation of the organic matter. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. The clear solution obtained was analysed for the selenium content by graphite furnace atomic absorption spectrometry. Unreduced palladium-nitrate modifier was used in all cases. However, in case of samples that are known to contain sulfur (like mushroom, Brazil nut, etc.), reduced palladium was used as modifier. The method was verified using three standard reference materials i.e., Whole egg powder-8415, Tuna fish-IAEA 350, Oyster tissue-1566a, and the results were in agreement at 95% confidence level. By using standards addition as calibration method, accurate results were obtained for the certified reference material, the precision for the CRM’s were in the range of 3.5–8%. The characteristic mass of selenium is assessed as 10 pg. The detection limits were in the range of 35–40 ng/g.     

Chromium determination in food by slurry sampling graphite furnace atomic absorption spectrometry using classical and permanent modifiers

A simple method, using permanent modifiers, has been developed for chromium (Cr) determination in food of plant origin by the slurry sampling graphite furnace atomic absorption spectrometry. In particular comparison of the action of Mg(NO₃)₂, iridium (Ir)/niobium (Nb) and iridium (Ir)/tungsten (W) was examined. Finally, for chromium determination in food, the mixture of 2 μg of Ir with 10 μg of Nb was used as permanent modifier. The analytical procedure was optimised carefully on the basis of the data from pyrolysis and atomisation temperature curves studies. The results obtained for four certified reference materials using external calibration with aqueous standards were in good agreement with the certified values. The precision and accuracy of Cr determination by the described method were also acceptable: the RSD were lower than 10% and recoveries for CRMs were in the range of 95-103%. The characteristic mass for chromium was determined to be 3.9 pg and the detection limit for the optimised procedure at the 0.75% (w/v) slurry concentration - 86.6 ng g⁻¹.     

原子吸收法测定海带微量元素的含量

用灰化法溶解试样,配制混合标准系列溶液,采用空气-乙炔火焰原子吸收法测定海带中11种微量元素含量。建立了优化的仪器测试条件,方法简便、准确。结果表明,干海带中含Ca、Mg、K为1.65～62.31mg/g;Sr为185.9μg/g;Fe为529.3μg/g;Ni、Cu、Mn、Zn为16.28～52.48μg/g;Cd为0.93μg/g;Pb为1.35μg/g,结果满意。     

Study of a microwave digestion method for total arsenic determination in marine mussels by electrothermal atomic absorption spectrometry: application to samples from the Ria de Arousa

Arsenic determination in mussel tissue was performed by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman background correction and using iridium as a chemical modifier. Samples were digested by microwave heating using a mixture of nitric and sulphuric acids. This mixture makes possible the destruction of organoarsenic compounds, specifically arsenobetaine, prior to the graphite furnace determination. Optimum pyrolysis and atomization temperatures were 1,100 and 1,800 °C, respectively. The method was precise (with RSD% < 10), accurate (study of a certified reference material: 18.4 ± 1.4 μg As g⁻¹ vs. a certified content: 18.0 ± 1.1 μg As g⁻¹; recoveries between 90 and 104%) and sensitive (LOD 0.21 μg g⁻¹ on a dry weight basis). The method was applied to the determination of arsenic in aquaculture mussels collected in four sampling campaigns from the productive Ría de Arousa (estuary sited in Galicia, NW of Spain).     

原子吸收光谱法测定苹果中重金属元素

采用HNO3-HClO4-H2SO4（4∶1∶1）混酸作消化液,在常压微沸条件下消解苹果样品,用火焰原子吸收光谱法（FAAS）测定了苹果中的Zn、Fe、Cu、Mn、Cd五种元素的含量,用流动注射-氢化物发生-原子吸收光谱法（FI-HG-AAS）测定了As、Hg、Pb三种元素的含量。采用正交实验研究了测定不同元素时仪器工作的最佳条件,确定了合适的样品消化体系,并作了方法的准确度、加标回收率和精密度考察。实验结果表明,苹果中的Zn、Fe、Cu、Mn、Cd、As、Hg、Pb含量分别为2.25、12.6、1.24、3.27、0.44、0.0017、0.0024、0.036mg·kg-1。方法的加标回收率为84.8%～109.6%,相对标准偏差RSD≤3.19%（n=5）。测定方法准确可靠,简单易行。      

Determination of sodium,potassium, calcium,magnesium, zinc and iron in emulsified chocolate samples by flame atomic absorption spectrometry

In this study, oil-in-water formulations were optimized to determine sodium, potassium, calcium, magnesium, zinc, and iron in emulsified chocolate samples by flame atomic absorption spectrometry (FAAS). This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures and allows the calibration to be carried out using aqueous standards. Octyl stearate was used as oily phase. Tween 80 and Triton X100 were tested as surfactants. The optimum type and proportion of formulations were determined and their choice depended on the element studied. The emulsion preparation was performed by a conventional method that involves mixing both phases at 75 ± 5 °C by magnetic stirring and phase inversion to change the water-to-oil ratio by increasing the volume of the surfactant-water external phase and correspondingly decreasing the volume of internal phase. The validation of the method was performed against a baking chocolate standard reference material (SRM 2384) and recoveries ranged from 88.6% for K to 105.5% for Zn. The proposed method allowed the evaluation of the essential metal status of chocolate with minimum sample manipulation and was reproducible and economical.     

原子吸收光谱法测定守宫木中的微量元素

采用火焰原子吸收光谱法连续测定了守宫木中Co、Cr、Cu、Zn、Ni、Fe、Mg、Ca和Pb九种微量元素的含量。其方法的相对标准偏差RSD为0.35%～2.34%,平均回收率在98.5%～110.4%之间。分析结果表明:守宫木中含有人体所需的微量元素,其含量顺序为:Mg>Ca>Fe>Zn>Cu>Ni>Co>Cr,未检测出有害元素Pb,说明守宫木具有较高的食用价值。     

火焰原子吸收光谱法测定大豆豆渣中镁的含量

应用火焰原子吸收分光光度法测定大豆豆渣中镁的含量,实验结果表明,该方法有很好的线性关系,相关系数为0.994,加标回收率为90.4%～109.5%,相对标准偏差为5.5%,该方法简便、快速、准确度高、重现性好。     

浊点萃取-火焰原子吸收光谱法测定啤酒中痕量铅

研究了以双硫腙作为络合剂、聚乙二醇辛基苯基醚（TritonX-100）为萃取剂的浊点萃取-火焰原子吸收光谱法（CPE-FAAS）测定酒中痕量铅的方法。研究了pH、平衡温度和平衡时间、络合剂用量、萃取剂用量和共存离子干扰等对萃取效果的影响。方法线性范围为100～800μg/L,检出限为3.25μg/L,回收率在95.9%～98.7%之间。方法简单、安全、快捷、灵敏、高效,适于啤酒中痕量铅的含量测定。      

火焰原子吸收光谱测定铜基金刚石工具中的镍

铜基结合剂金刚石工具中镍的测定,使用化学分析和可见光光度法测定时,步骤烦琐,试剂使用量大。实验采用火焰原子吸收分光光度法测定铜基金属结合剂中镍的含量,不需分离基体铜,直接测定镍含量。回收率98.9%～99.5%,相对标准偏差RSD为1.96%～2.46%,工作曲线的回归系数：γ=0.99834,方法可靠。     

火焰原子吸收分光光度法测定土壤中的钴元素

本文介绍了利用火焰原子吸收分光光度法测定土壤中钴元素.通过改进土壤电热板消解方法使土壤中的钴元素完全消解于溶液中,该方法快速、准确、方便.在土壤实际样品分析中,回收率为91％-111％,相对标准偏差为1.2％-5.0％,对实际样品测试取得了满意的结果.     

原子吸收光谱法测定辣椒及辣椒食品中的微量元素

应用火焰原子吸收光谱法对辣椒及辣椒食品中的Cu、Na、Fe、K、Sr、Mg、Ca、Mn、Zn等9种微量元素的含量进行测定分析。结果显示:Cu、Na、Fe、K、Sr、Mg、Ca、Mn、Zn的标准曲线相关系数为0.9999、0.9820、0.9997、0.9927、0.9982、0.9965、0.9991、1.0000和0.9985;辣椒及辣椒食品中均能检出这9种微量元素,其中辣椒籽中的Cu、Mg、Mn、Zn含量很高;制成辣椒食品后,Na含量大幅度增加,而相对于其他香辣酱,鲜食辣椒酱Na含量最低;辣椒制成辣椒食品后部分微量元素富集(如Cu、Na、Fe、Ca等)比鲜冻辣椒中微量元素含量高。      

Direct determination of copper,lead and cadmium in aniseed spirits by electrothermal atomic absorption spectrometry

Direct determination of copper, lead and cadmium by electrothermal atomic absorption spectrometry in aniseed spirits was proposed. The methods were validated by studying quality parameters such as trueness, precision, linearity and sensitivity. Recoveries ranging between 96% and 104% were obtained from spiked samples at several concentration levels. Repeatability was less than 5% and intermediate precision was less than 8%. The procedure is fast and shows limits of detection of 0.6, 0.7 and 0.04 μg l⁻¹ for Cu, Pb and Cd, respectively. Samples were just diluted in a water/ethanol/nitric acid mixture. Cu was present at higher concentrations, with values in the range 6–473 μg l⁻¹. Minor levels of Pb and Cd were present with concentrations of less than 6 and 1.4 μg l⁻¹, respectively.     

原子吸收法测定奶粉中的钙、铁、锌

用硝酸和高氯酸处理奶粉后，以质量分数为0.22％硝酸镧为释放剂，采用火焰原子吸收法测定同一样品中的钙、铁、锌元素的含量．结果表明．在选用浓度为0．15mol／L硝酸作介质条件下，共存离子不干扰．测定的RSD均小于1．59％(n=5)．回收率在98.6％-101．6％之间，与国家标准方法测定的结果基本相符。     

连续光源火焰原子吸收光谱法同时测定蓝莓中Ca、Mg、Fe、Zn含量

建立高分辨率连续光源火焰原子吸收光谱法同时测定蓝莓中Ca、Mg、Fe、Zn方法。样品采用湿法消解处理样品,用连续光源原子吸收光谱仪对蓝莓中Ca、Mg、Fe、Zn的含量进行检测,并对方法的精密度、检出限和回收率进行分析。结果表明：方法测定出蓝莓中Ca、Mg、Fe、Zn含量分别为100.3、55.80、2.330、1.413 mg/kg,方法检出限分别为0.030、0.830、0.088、0.049 mg/L,相对标准偏差为1.9%～4.7%,回收率为94.6%～107.0%。本方法可对同时检测蓝莓等果蔬食品中多种金属元素的工作提供帮助,具有灵敏度高、效率高,稳定性好、操作简单的特点。     

石墨炉原子吸收法测定调味品中痕量铅

采用石墨炉原子吸收光谱法测定不同调味品中铅含量的分析方法.样品采用干法灰化处理,灰化温度为500℃,灰化时间为6h,残渣用1.0％硝酸溶解,然后加入硝酸铵做基体改进剂,优化了仪器条件后进样分析.铅浓度在0μg/L～50μg/L范围内呈良好线性关系,方法最低检出限在0.6μ g/L,回收率为83.80％～87.65％,相对标准偏差RSD为1.82％～3.40％.该方法是一种快速,灵敏,准确的分析方法,可用于调味品中铅的测定.     

微波消解-原子吸收法测定鸡精中金属元素

建立了微波消解-连续光源原子吸收光谱法测定鸡精中Ca、Fe、Mg、Zn的方法。实验选择微波消解作为样品的前处理方式,分析研究了乙炔流量和燃烧器高度对测定结果的影响,通过实验分别确定了测定Ca、Fe、Mg、Zn的最佳参数。在此条件下,利用高分辨连续光源原子吸收光谱仪测定鸡精中Ca、Fe、Mg、Zn的含量分别为:206.2、3.6、144.7、4.0μg/g,加标回收率为98.4%~106.7%,本法的精密度(RSD)为1.0%~2.2%。该方法快速、准确、稳定、污染少,具有较高的实用价值,为食品中多元素检测提供了科学依据。     

火焰原子吸收光谱法测定甜菜块根中铜、锌含量

采用微波消解——火焰原子吸收光谱法,对编号为GBW07604杨树叶、GBW07601人发的质控样及10个甜菜块根样品进行重金属铜、锌的检测,并且对这两种金属元素的最低检出限、精确度、准确度及样品差异进行分析。结果表明,应用本方法测定的铜、锌的最低检出限分别为0．0056mg／kg、0．0298mg／kg;铜在甜菜块根中的含量较低,在浓度范围0-0．8μg／mL与其吸光度呈良好的线性关系,线性方程为y=0．14579x＋0．0006,相关系数为0．9999。锌在浓度范围0-0．5μg／mL,与其吸光度也呈良好的线性关系,线性方程为Y=0．07157x＋0．0002,相关系数为0．9997。实验表明,本方法及仪器条件适合甜菜样品中铜、锌的检测。     

螯合萃取火焰原子吸收光谱法测定果汁饮料中痕量铜

利用高灵敏度的原子吸收光谱仪对果汁饮料和饮用水中的铜进行了测试。在测试中,采用了方便的HNO3消解法对样品进行预处理,通过实验研究了螯合物吡咯烷二硫代氨基甲酸铵用量对吸光度的影响,在样品测定液中加入吡咯烷二硫代氨基甲酸铵量为5ml时,完全能够满足铜离子螯合的需要;并研究了共存物质的影响。结果表明该方法选择性好,适用于果汁饮料和饮用水中痕量铜的测定。     

预富集-氢化物发生原子吸收光谱法测定水产品中的痕量硒

研究了预富集-氢化物发生原子吸收光谱法测定水产品中的痕量硒的新方法。用吡咯烷二硫代氨基甲酸铵(APDC)作配位剂,在pH4.0～6.5的条件下,用固体硅胶捕集、膜滤纸抽滤分离Se-APDC配合物,然后用0.1moL/L盐酸从膜滤纸上洗下硅胶,得到能够直接用氢化物原子吸收光谱法测定的硒悬浊液。该法操作简便,富集速度快。100mL溶液,特征质量为1.5×10-11g/1%。在最佳条件下,用这个方法测定了水产品中的痕量硒,当n=6时,标准偏差为0.0027～0.0054,变异系数为0.012～0.028,样品的加标回收率在95.2%～104.6%之间,结果较为满意。