低压微波消解——ICP-AES法测定聚氯乙烯塑料及其制品中的Pb、Cd、Cr和Hg

采用低压微波消解系统, 以HNO3、HCl、H2O2、HClO4和HF消解样品, 用H3BO3络合过量的F-, 并研究了Cl-对测汞的影响、共存元素的干扰、H3BO3对各元素的影响, 建立了低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中Pb、Cd、Cr和Hg的方法. Pb、Cd、Cr和Hg的检出限(3σ)分别为: 0.012、0.002、0.006、0.020 μg/mL, 相对标准偏差为0.5%～4.0%, 回收率为95%～101%. 该方法可推广应用到其它塑料中Pb、Cd、Cr和Hg的测定, 已应用于实际的检测工作.     

ICP-MS法测定亚热带水果中的重金属含量

用电感耦合等离子体质谱(ICP–MS)法测定亚热带水果中Pb,Cd,As,Hg元素的含量,对实验条件进行优化,样品用微波消解法进行预处理,用Bi,In,Ge作内标校正基体干扰和漂移。Pb,Cd,As的线性范围为0.0～20.0ng/mL,Hg的线性范围为0.0～2.0 ng/mL,线性相关系数均为0.999 9。Pb,Cd,As,Hg元素的检出限分别为0.027,0.008,0.011,0.051 ng/mL,测定结果的相对标准偏差(n=6)在3.63%～5.72﹪之间,加标回收率为90.2%～102.0%。用该法测定茶叶、大米和小麦3种国家标准物质,测定结果均在标称值范围内。     

低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中的Pb、Cd、Cr和Hg

采用低压微波消解系统,以HNO3、HCl、H2O2、HClO4和HF消解样品,用H3BO3络合过量的F-,并研究了Cl-对测汞的影响、共存元素的干扰、H3BO3对各元素的影响,建立了低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中Pb、Cd、Cr和Hg的方法。Pb、Cd、Cr和Hg的检出限(3σ)分别为:0.012、0.002、0.006、0.020μg/mL,相对标准偏差为0.5%~4.0%,回收率为95%~101%。该方法可推广应用到其它塑料中Pb、Cd、Cr和Hg的测定,已应用于实际的检测工作。     

微波消解-石墨炉原子吸收光谱法测定污水厂污泥和进、出水中的镉、铅

建立了微波消解–石墨炉原子吸收光谱法测定污水处理厂进出水和污泥中重金属Cd,Pb的方法。分别向污水样品中加入5.0 mL硝酸,污泥样品中加入4.0 mL硝酸和2.0 mL双氧水,放入微波消解炉中进行消解。消解好的样品用1%NH_4H_2PO_4作为基体改进剂,在0.5%HNO_3介质中采用塞曼扣除背景,石墨炉程序升温方式进行Cd,Pb的原子化,用石墨炉原子吸收光谱法测定Cd,Pb的含量。Cd,Pb的质量浓度分别在0~2.00μg/L,0~40.0μg/L范围内与其吸收峰高呈良好的线性关系,线性相关系数分别为0.999 1,0.999 6。Cd,Pb检出限分别为0.104 9,0.394 5μg/L,测定结果的相对标准偏差分别为1.34%~3.61%,2.12%~2.80%(n=11),加标回收率分别为98.2%~102.6%,94.0%~100.4%。该方法简单,高效,结果准确度高,重现性好,适用于污水处理厂的进出水和污泥中重金属铅和镉的检测。     

微波消解-石墨炉原子吸收法快速检测葡萄酒中铅、镉

葡萄酒样品采用电热消解仪140 ℃预消解30 min后,经过微波消解仪处理,消解条件为:V(HNO3)∶V(H2O2)＝7∶1,180 ℃,800 W,10 min,然后采用石墨炉原子吸收法对其中铅、镉含量进行测定.研究表明,将本法应用于葡萄酒样品中Pb、Cd的测定,结果令人满意,Pb和Cd的检测限分别为3.0 μg/L和0.5 μg/L,RSD均小于5.0%,回收率Pb 74.5%～101.5%,77.3%～104.3%.     

微波消解ICP-MS测定海洋沉积物中微量元素

采用微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定海洋沉积物中的Cr、Co、Ni、Cu、Zn、Cd、Pb7种微量元素。对微波消解酸体系和微波程序进行了优化,结果表明:由4 mL HNO3与2 mL HF组成的混合酸对沉积物消解效果好;阶段升温,最高温度200℃,消解30 min有着最佳的消解效果。采用本实验方法对7种不同类型的海洋沉积物标准物质进行了测定,测定结果与标准值一致。各元素的检出限在0.009~0.17 ng/g之间。该方法快速简便、准确度高,可用于海洋沉积物样品中多元素同时测定。     

球形立方相纳米二氧化铈-ICP-MS法同时测定痕量铅和镉

采用室温固相法合成球形立方相纳米CeO2,建立了纳米CeO2富集分离,ICP-M S同时测定痕量Pb(Ⅱ)和Cd(Ⅱ)的方法。在pH 7.0,10 mg CeO2,吸附15min后,纳米CeO2对Pb(Ⅱ),Cd(Ⅱ)的吸附率均可达100%;以2mL 0.05 mol/L HCl溶液为洗脱剂、洗脱20 min后,对Pb(Ⅱ)和Cd(Ⅱ)的洗脱率可分别达到98%和95%以上;纳米CeO2对Pb(Ⅱ),Cd(Ⅱ)的最大静态吸附容量分别为496.9μg/g和243.1μg/g,富集倍数均可达250倍,共存离子影响小。优化ICP-MS仪器工作条件,选择205Bi和115In为在线内标进行Pb(Ⅱ)和Cd(Ⅱ)的测定,检出限分别为1.7 pg/mL和9.2 pg/mL,RSD分别为4.8%和0.94%。方法应用于实际水样,回收率分别为Pb(Ⅱ)93.6%~106.4%,Cd(Ⅱ)96.2%~108.9%。     

电感耦合等离子体质谱法分析死后人体血液与一般人群血液中9种金属元素含量差异

建立了血液样本中金属元素的微波消解-电感耦合等离子体质谱(ICP-MS)检测方法。通过优化消解条件,以铋(Bi)和铟(In)双内标校正,对死后人体血液样本和一般人群对照样本中镁(Mg)、铬(Cr)、砷(As)、锶(Sr)、镉(Cd)、钡(Ba)、汞(Hg)、铊(Tl)、铅(Pb)9种金属元素含量进行了检测,并运用统计学方法比较了其差异与关联性。结果表明,在2 mL双氧水、5 mL硝酸、190℃的消解条件下,样品的消解效果较好。9种元素线性良好,相关系数(r²)不小于0.997 7,检出限为0.000 4～0.049 6 ng/mL,加标回收率为86.5%～110%,日内相对标准偏差(RSD)为0.50%～5.9%,日间RSD为2.5%～8.5%,回收率和精密度符合检测要求。9种金属元素数据均不符合Komogorov-Smirnov正态性检验,而两组数据的Mann-Whitney U检验结果存在显著差异(P <0.05)。采用Spearman秩相关分析金属之间的相关性,发现大多数金属元素之间显著相关。通过建立二分类Logistic回归模型,研究了样本类型与血样...     

智能石墨消解–ICP–MS法测定空气PM2.5中的Pb和Cd

建立电感耦合等离子体质谱(ICP–MS)测定空气PM2.5中的Pb和Cd元素的分析方法。采用连续β射线–DHS PM2.5大气颗粒物浓度监测仪采集空气中的PM2.5,以智能石墨消解PM2.5滤膜样品,ICP–MS测定其中的Pb和Cd元素含量。在优化的仪器条件下,元素Pb和Cd标准曲线的线性相关系数均为0.999 9,检出限分别为0.018,0.52ng/m3,满足HJ 657–2013的要求。Pb和Cd的加标回收率分别为95.8%~101.4%,99.3%~104.9%,测定结果的相对标准偏差分别为4.20%和2.38%(n=6)。对滤膜标准样品进行了测定,测定结果与标准值一致。该方法测定结果准确、可靠,可用于测定空气PM2.5中的Pb和Cd。     

微波消解-ICP-AES法测定塑料中Pb和Cd

采用微波消解法进行溶样,以ICP-AES法测定塑料中Pb和Cd的含量。Pb、Cd的回收率分别为96.0%~102.0、93.3%~105.0%。Pb、Cd测定结果的相对标准偏差分别为0.567%、1.19%(n=10)。Pb和Cd的检出限分别为0.02、0.005 mg/L。该方法适用于多种塑料中Pb和Cd含量的快速分析。     

Preconcentration of trace metals from salt solutions using thiuram disulphide as collector

Traces of Fe, Co, Ni, Cu, Zn, Cd and Pb in salt solutions (e.g. KCl, Ca(NO₃)₂, A1₂(SO₄)₃, Cr₂(SO₄)₃, (NH₄)₂SO₄) are determined by flame AAS after preconcentration with thiuram disulphide (TDS) as collector precipitate. The preconcentration recovery is mainly influenced by pH, TDS amount and its aging in the sample solution. Conditions of an optimal preconcentration procedure were elaborated. Detection limits vary from 0.5 ng/ml (for Cd) to 8.3 ng/ml (for Pb) and the relative standard deviation is 2 to 6 %. The accuracy of the results was checked by differential pulse anodic stripping voltammetry and by electrothermal AAS.     

Solid phase extraction and flame atomic absorption spectrometric determination of trace amounts of cadmium and lead in water and biological samples using modified TiO2 nanoparticles

A solid phase extraction procedure for the separation and preconcentration of trace amounts of Cd(II) and Pb(II) using the alizarin red S modified TiO₂ nanoparticles prior to their determination by flame atomic absorption spectrometry has been proposed. The influences of some analytical parameters such as pH, flow rates of sample and eluent, type and concentration of the eluent, and interfering ions on the recovery of Cd(II) and Pb(II) by the sorbent were investigated. The analytes were quantitatively sorbed from the aqueous solution at pH 5.5 onto a microcolumn packed with the sorbent and recovered with 2.0?mL of 1.5?mol?L^?1 hydrochloric acid. Under the optimum experimental conditions, the detection limits for Cd(II) and Pb(II) were 0.11 and 0.30?ng?mL^?1 and the relative standard deviations for ten replicate measurements of 5.0 and 50.0?ng?mL^?1 of Cd(II) and Pb(II) were 2.1 and 1.9%, respectively. A sample volume of 200?mL resulted in a preconcentration factor of 100. The method was successfully applied to the determination of Cd(II) and Pb(II) in water and biological samples, and accuracy was examined by the recovery experiments, independent analysis using electrothermal atomic absorption spectrometry, and analysis of a water standard reference material (SRM 1643e).     

间断多次扫描电位溶出分析方法的研究

间断多次扫描电位溶出分析是在多次扫描电位溶出分析和间断扫描伏安法的基础上提出的一种新的电位溶出分析技术,它不仅具有多次扫描电位溶出分析灵敏度高的优点,又克服了多次扫描电位溶出分析对多元素分析时元素之间相互干扰的缺点。文章讨论了间断多次扫描电位溶出分析的实验条件,同时用这种方法分析了人尿中镉、铅的含量。间断多次扫描电位溶出分析在电积10分钟时,最低可检测到0.005ng/mL的镉和0.01ng/mL的铅。镉、铅浓度为4ng/mL时,相对标准偏差分别为2.9%和3.2%,证明间断多次扫描电位溶出分析可以同脉冲阳极溶出伏安法媲美。     

Use of thermal ionization isotope dilution mass spectrometry (TI-IDMS) as an oligo-element method for the determination of photographically relevant trace elements in AgCl emulsions

Thermal ionization isotope dilution mass spectrometry (TI-IDMS) was used as an oligo-element method for the determination of Cr, Cd and Pb in photographic AgCl emulsions. After addition of an appropriate amount of isotopically enriched spikes (⁵³Cr, ¹¹⁶Cd and ²⁰⁶Pb) to the solid samples, the latter were completely dissolved in NH₃ solution, permitting isotopic exchange to take place. Thereafter, AgCl was selectively removed by precipitation, whereby ultrasonic treatment was used to enhance the recovery of the elements of interest. Despite the use of concentrated HNO₃ and H₂O₂ during further sample processing, preliminary experiments indicated the presence of a substantial remainder of the organic matrix (gelatine). Hence, the analytes of interest were isolated by means of electrolytic deposition on Pt electrodes. Subsequently, the deposits were dissolved from the Pt electrodes using a mixture of concentrated HNO₃ and H₂O₂ and the solutions evaporated to dryness. The solid residues were taken up in diluted HNO₃ and loaded onto Re filaments. In order to improve the ionization yield, prior to the sample, a silicagel suspension containing AlCl₃ was loaded onto the filament and after sample loading, both H₃BO₃ (for Cr and Pb) and H₃PO₄ (for Cd and Pb) were added as further ionization aids. Finally, the isotope ratios of interest (⁵²Cr/⁵³Cr, ¹¹⁴Cd/¹¹⁶Cd and ²⁰⁶Pb/²⁰⁸Pb) were determined using thermal ionization mass spectrometry, whereby all three analyte elements were vaporized from the same filament. The limits of detection obtained using this procedure range from 0.4 ng (for Cd) to 4 ng (for Pb). Four different AgCl emulsions were analyzed. For Cr, the concentration found was quite similar for all emulsions analyzed, as it varied between ～ 40 and ～ 100 ng/g only. For Cd, very low values were found for all samples analyzed (≤ 3 ng/g). Finally, for Pb a much larger variation from ～ 10 ng/g up to ～ 5.5 μg/g was observed. For the sample with the highest Pb content, an excellent agreement could be established between the results obtained using quadrupole-based ICP-IDMS and those using TI-IDMS. For the determination of Cr by means of quadrupole-based ICP-IDMS, an instrument equipped with a ShieldTorch system was used to avoid spectral overlap of the ⁵²Cr⁺ and ⁴⁰Ar¹²C⁺ ion signals. Also in this case, the results obtained are in very good agreement with those obtained using TI-IDMS. The comparison between TI-IDMS and ICP-IDMS also made clear that sample inhomogeneity limits the between-sample precision attainable.     

A pre-enrichment procedure using diethyldithiocarbamate-modified TiO2 nanoparticles for the analysis of biological and natural water samples by ICP-AES

In this article, a new method that utilizes a diethyldithiocarbamate-modified nanometre TiO₂ (TiO₂–DDTC) as solid-phase extractant has been developed for simultaneous preconcentration of trace Cu(II), Pb(II), Zn(II), and Cd(II) prior to measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). The separation/preconcentration conditions of analytes, which include the effects of pH, sample flow rate and volume, elution conditions, and interfering ions on the recovery of the analytes, were investigated. At pH 5, the adsorption capacity of modified nanometre TiO₂–DDTC was found to be 6.2, 19, 4.7, and 6.0?mg/g for Cu(II), Pb(II), Zn(II), and Cd(II), respectively. According to the definition of IUPAC, the detection limits (3σ) of this method for Cu(II), Pb(II), Zn(II), and Cd(II) were 0.41, 1.7, 0.39, and 0.52?ng/mL, respectively. The proposed method achieved satisfied results when applied to the determinations of trace Cu(II), Pb(II), Zn(II), and Cd(II) in biological and natural water samples.     

Determination of heavy metals and iodide by stripping voltammetry in sodium chloride on mercury-graphite electrodes

The behavior of Cd(II), Pb(II), Cu(II), and I⁻ in the aqueous solutions of sodium chloride is studied by stripping voltammetry. A new version of using an indicator electrode from carbon glass ceramics modified with mercury for the consecutive stripping determination of Cd(II), Pb(II), Cu(II), and iodide is proposed. The mercury-graphite electrode was formed in the solution of a supporting electrolyte based on NH₄Cl, HCl, 0.05 M potassium tetraoxalate (KH₃C₄O₃ · 2H₂O), and 5 × 10⁻⁵ M mercury(II). At first, Cd(II), Pb(II), Cu(II), and then iodide were determined by anodic-cathodic stripping voltammetry after adding a sample solution (table salt, 10–100 mg/mL NaCl).     

Determination of heavy metal traces in metallic materials with IDMS

Summary Two pure copper samples were analysed for Cr, Ni, Zn, Cd, and Pb with isotope dilution mass spectrometry (IDMS) as a part of a certification campaign of the European Community Bureau of Reference in Brussels. Additionally, one commercially available copper powder was determined for Zn, Cd, and Pb. After dissolution of the sample in aqua regia Pb was separated from the matrix by anodic electrodeposition, the other elements by anion-exchange chromatography. Positive thermal ions were produced in a single-filament ion source using the silica gel technique with phosphoric acid for Zn, Cd, and Pb and with boric acid for Cr and Ni. Most of the heavy metals could be determined with relative standard deviations of about 1% down to the ng/g level. The detection limits were 13 ng/g for Zn, 4 ng/g for Ni, 2 ng/g for Cr, 1 ng/g for Pb, and 0.03 ng/g for Cd. The results were compared with those obtained by another IDMS laboratory and by other methods applied during the certification campaign.

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Bestimmung von Schwermetallspuren in metallischen Werkstoffen mit der massenspektrometrischen IsotopenverdünnungsanalyseTeil 1. Bestimmung von Cr, Ni, Zn, Cd und Pb in reinem Kupfer

     

Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l⁻¹ HNO₃ and in 1+1 v/v diluted wine using mixtures of Pd(NO₃)₂+Mg(NO₃)₂ and NH₄H₂PO₄+Mg(NO₃)₂ as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l⁻¹ HNO₃, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10–1.0 μg l⁻¹ Cd and 5.0–50 μg l⁻¹ Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l⁻¹ for Cd, 0.8 μg l⁻¹ for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l⁻¹ and for Pb at 500 μg l⁻¹. The relative standard deviations (n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.     

纳米Al2O3微柱分离/富集-石墨炉原子吸收法测定环境试样中的痕量铅和镉

本文将纳米氧化铝微柱分离系统与石墨炉原子吸收光谱法联用,用于测定环境水样中的痕量铅和镉。较系统地考察了纳米Al2O3材料对镉和铅离子的吸附性能及影响因素;在优化的实验条件下本法对Pb和Cd的检出限(3σ)分别为0.189 ng/mL和0.0039 ng/mL;RSD%分别为3.9%和2.9%。     

Simultaneous Determination of Aluminum,Cadmium and Lead in Whole Blood by Simultaneous Atomic Absorption Spectrometry with Oxygen Charring

A method for the simultaneous determination of aluminum (Al), cadmium (Cd) and lead (Pb) in whole blood has been developed by using simultaneous atomic absorption spectrometry (SIMAAS) with oxygen charring. The optimized conditions for the simultaneous determination of Al, Cd and Pb were obtained in the presence of palladium (Pd) as the chemical modifier, using 600 °C and 2400 °C as the pyrolysis and the atomization temperature, respectively. The whole blood samples were diluted 1+5 (v/v) directly with 0.1% (v/v) Triton X‐100. Oxygen was employed to eliminate the interference of carbonaceous residues in the charring step before pyrolysis. The calibration curves were carried out with aqueous standard solutions and the linear ranges were 0–40 ng mL⁻¹, 0–4 ng mL⁻¹ and 0–40 ng mL⁻¹ for Al, Cd and Pb, respectively. The detection limits were 0.96 ng mL⁻¹ (19.2 pg) for Al, 0.03 ng mL⁻¹ (0.6 pg) for Cd and 0.60 ng mL⁻¹ (12.0 pg) for Pb. The spiked recoveries of Al, Cd and Pb in whole blood were 98.0%, 100.0% and 101.7%, respectively. The accuracy of the proposed method was evaluated with the analysis of a whole blood certified reference material (Seronorm, level 2). The found concentrations were in agreement with the recommended values. The proposed method has been successfully applied to the simultaneous determination of Al, Cd and Pb in whole blood of healthy volunteers before and after eating barbecued foods.