同位素稀释热电离质谱法测定人血清中痕量铜和锌

采用热电离同位素稀释质谱法(ID-TIMS)准确测定了欧盟标准物质与测量研究院(EC-JRC-IRMM)组织的国际测量评估计划IMEP-17人血清样品中的痕量铜和锌。由于锌和铜都是易受污染的元素,本工作建立了仅用少量硝酸消解的低流程本底和适于热电离质谱测量的生物基体血清中痕量铜和锌的样品前处理方法;采用适当比例的硅胶和磷酸作为电离增强剂,在热电离质谱(TIMS)测量时获得了较高强度且稳定的铜和锌离子束;血清中痕量铜和锌的测量结果可直接溯源到国际单位mole。2种人血清样品中铜和锌测量结果的不确定度(k=2)分别为0.94%、0.83%和0.49%,测量值被EC-JRC-IRMM采用作为该样品的标准值。     

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 Ba, Cd, Cu, Pb and Zn in saliva by isotope dilution direct injection inductively coupled plasma mass spectrometry

Trace elements in small sample volumes of saliva were determined by coupling a high efficiency direct injection nebulizer to inductively coupled plasma mass spectrometry and employing quantification by isotope dilution. Aliquots of 0.4 ml of human saliva were mixed with 0.1 ml of concentrated nitric acid and diluted to 2 ml with water. Sample solutions were spiked with an isotopic solution enriched in 135Ba, 112Cd, 65Cu, 206Pb and 66Zn. The amount of each isotope added to the samples and the measurement procedure were adjusted to attain precise analytical results calculated from the isotope ratios 135Ba/138Ba, 112Cd/114Cd, 65Cu/63Cu, 206Pb/208Pb and 66Zn/68Zn. Data acquisition for Ba, Cu and Zn isotopes was performed for a single sample injection of 50 microl and in another sample injection the Cd and Pb isotopes were measured. Concentrations ranging from 5.0 to 16 microg l(-1) for Ba, from 0.50 to 1.1 microg l(-1) for Cd, from 6.0 to 50 microg l(-1) for Cu, from 0.8 to 18.8 microg l(-1) for Pb and from 46.0 to 230 microg l(-1) for Zn were found in saliva samples. Detection limits of 0.11, 0.03, 0.40, 0.05 and 0.59 microg l(-1) were determined for Ba, Cd, Cu, Pb and Zn, respectively. The concentrations found by isotope dilution were in agreement with those of the completely digested samples quantified by external calibration. The direct analysis of 30 samples per hour was attained with the proposed procedure, avoiding time-consuming digestion steps, contamination risks and matrix effects.     

Evaluation of Ammonium Oxalate for Fractionating Metallic Trace Elements in Soils by Sequential Extraction

Abstract

Ammonium oxalate is largely used to extract the trace elements bound to Mn-oxides, amorphous compounds and crystalline Fe-oxides. The objective of this work was to evaluate the selectivity and the efficiency of ammonium oxalate for extracting Cd, Cu, Ni, Pb and Zn by sequential extraction of soils. For this purpose, three schemes were selected and applied to three different soil samples of the Swiss Jura. Each extraction scheme consisted of six steps, where different reagents were used to extract Cd, Cu, Ni, Pb and Zn bound to the Mn and Fe compounds. The results showed that metallic trace elements extraction with ammonium oxalate are very dependant on the metal studied. The reason could be the capability of oxalate to form stable complexes with the metals considered which sometimes are only slightly soluble.     

Multielemental Analysis of Human Serum by Dynamic Reaction Cell–Inductively Coupled Plasma Mass Spectrometry

The selection of the most suitable dilution methods for determination of trace elements in human serum using inductively coupled plasma mass spectrometry is reported. The trace elements were Al, V, Cr, Fe, Mn, Co, Cu, Zn, As, Cd, Sn, Tl, and Pb. The performance of various dilution methods was assessed by precision, linearity, detection limits, quantification limits, fortified recoveries, and the analysis of reference materials. The results demonstrate that diluted solution containing only nitric acid is most suitable for As, Cr, Mn, and Co in serum. Dilute solutions containing nitric acid and Triton X-100 were most appropriate for Cu, Zn, Cd, and Tl. The optimum conditions for Al, V, Mn, Fe, Cr, Co, Sn, and Pb used tetra-n-butylammonium hydroxide, Triton X-100, and ethylenediamine tetraacetic acid.     

Hollow-fiber liquid-phase microextraction prior to low-temperature electrothermal vaporization ICP-MS for trace element analysis in environmental and biological samples

A new method of hollow-fiber liquid-phase microextraction (HF-LPME) prior to electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi, based on gaseous compounds introduction into the plasma as their diethyldithiocarbmate (DDTC) chelates, was developed. The use of the reagent DDTC as chemical modifier could not only enhance the analytical signals, but also decrease the vaporization temperature. At a temperature of 1300 degrees C, trace Cu, Zn, Pd, Cd, Hg, Pb and Bi can be vaporized completely into the ICP. The factors affecting the formation of the chelates and their vaporization behaviors were investigated in detail, and the microextraction conditions were optimized. Under the optimized conditions, the detection limits of the proposed method were 12.4, 28.7, 7.9, 4.5, 3.3, 4.8 and 1.6 pg ml(-1) for Cu, Zn, Pd, Cd, Hg, Pb and Bi, respectively. Enrichment factors of 305, 284, 24, 29, 20, 73 and 43 could be achieved within 15 min of extraction time, and the relative standard deviations (RSDs) for the seven determinations of 0.5 ng ml(-1) of target analytes were 8.8, 6.9, 7.1, 9.4, 10.2, 6.1 and 10.8%, respectively. The newly developed method has been applied to the determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi in environmental water and human serum samples, and the recoveries for the spiked samples were in the range of 88-116%. In order to validate this method, two certified reference materials, GBW08501 peach leaves and GBW(E)080040 seawater, were analyzed, and the determined values were in good agreement with the certified values.     

松口蘑中微量元素的测定

采用火焰原子吸收法同时测定了松口蘑中K、Ca、Na、Mg、Fe、Pb、Cd、Co、Cr、Zn、Mn、Cu等12种元素的含量。方法的相对标准偏差在0.08％－2.32％范围,回收率在97.1%－108.3%范围。结果表明,在三种松口蘑样品中,除含有较高的K、Na、Ca、Mg和一定量的有害元素Cd、Pb外,其余6种对人体有益的微量元素较为丰富。     

原子吸收光谱法测定皇冠草地上部分的7种微量元素

采用原子吸收光谱法测定了皇冠草地上部分所含微量元素铜、锰、锌、铁、镉、铅、铬.结果表明,皇冠草地上部分含有较丰富的铜、锰、锌、铁,RSD≤4.23％(n=4),加标回收率99.20％～103.00％.     

The interlaboratory comparison "IMEP-19 trace elements in rice"—a new approach for measurement performance evaluation

The aim of IMEP is to present objectively the quality of chemical measurements. Participants in IMEP compare their reported measurement results with independent external certified reference values with demonstrated traceability and uncertainty, as evaluated according to international guidelines. IMEP-19 focused on measurements of trace elements in rice aiming to support the Commission Regulation (EC) No. 466/2001 on maximum levels for certain contaminants in foodstuff. Measurement results for the elements Cd, Cu, Pb and Zn were reported by 267 field laboratories involved in food analysis from 43 countries. Performance criteria for the evaluation of the reported measurement results in IMEP-19 are suggested. The chosen performance indicators not only take into account the deviation of the reported measurement value from the certified reference value, but also set criteria for maximum and minimum acceptable uncertainty. The IMEP-19 participants' performance is reviewed by means of using new simple graphical tools, called "Naji plots".     

Method validation for determination of 13 elements in honey samples by ICP-MS

A method for simultaneous ICP-MS determination of 13 elements in three types of honey from Poland is described. The method was validated, and the uncertainty budget was set up. The results obtained for the relative expanded uncertainties U _rel (k = 2) were 15.1% for Al, 18.6% for B, 18.8% for Ba, 7.9% for Ca, 24.4% for Cd, 7.24% for Cu, 7.9% for K, 4.8% for Mg, 8.3% for Mn, 12.7% for Na, 14.9% for Ni, 12.5% for Pb and 13.4% for Zn. Traceability of the measurement results was established based on the use of the corn flour CRM INCT-CF-3 and the apple leaves CRM SRM 1515 and by analyzing spiked samples. Recovery rates between 94% (Zn) and 107% (Na) were found. The detection limits of all elements studied showed the suitability of the procedure for routine analyses. Summarizing it can be concluded that the described analytical procedures to measure the mass fractions of 13 elements in honey samples with established traceability and evaluated uncertainty allow to obtain reliable and internationally comparable results.     

海水中铜锌铅镉的萃取-反萃取法同时提取-原子吸收光谱法测定

采用萃取-反萃取法同时提取出海水中Cu、Zn、Pb、Cd,Cu、Pb、Cd石墨炉法测定,Zn用火焰法测定.对样品的前处理方法和最佳仪器条件进行了研究,并通过加标实验验证了方法的可靠性.结果表明:萃取-反萃取法能完全满足海水中Cu、Zn、Pb、Cd的前处理要求,可节省一半前处理时间,有溶液稳定、环保、节省试剂等优点.     

六极杆碰撞反应池–ICP–MS法测定海水中痕量金属元素

建立了直接稀释法测定海水中痕量金属元素Cr,Cu,Zn,Cd,Pb的方法。样品经稀释10倍后,使用基体匹配及内标校正,采用六极杆碰撞反应池–电感耦合等离子体质谱仪直接测定稀释后海水样品中的5种元素Cr,Cu,Zn,Cd,Pb。各元素在0.0~100μg/L范围内均呈现良好的线性关系,线性相关系数(r~2)均大于0.999 0,方法检出限为0.004~0.209μg/L。测定结果的相对标准偏差为2.4%~4.4%(n=6),加标回收率为92%~113%。该方法简单快捷,适用于近岸海水中痕量元素Cr,Cu,Zn,Cd,Pb的分析。     

Interlaboratory study of trace and other elements in the iaea powdered human hair reference material,HH-1

A powdered intercomparison material for trace element studies was prepared from human scalp hair and distributed to more than 100 laboratories of which 66 reported results for altogether more than 40 elements. By statistical evaluation of these data certified concentration values were derived for 20 elements, namely As, Au, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Mg, Mn, Na, Pb, S, Sb, Se, Sr and Zn. The data also made it possible to compare different methods of analysis and to judge the value of different levels of experience on the part of the analyst concerned; these comparisons are presented here with special reference to the elements As, Cd, Hg, Pb and Sb.     

Certified reference material for the quality control of cadmium,copper nickel and zinc determination in estuarine water (CRM 505)

Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V.     

Certified reference material for the quality control of cadmium, copper nickel and zinc determination in estuarine water (CRM 505)

Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V.     

Simultaneous determination of speciation parameters of Cu,Pb, Cd and Zn in model solutions of Suwannee River fulvic acid by pseudopolarography

There is a growing awareness of the importance of quantitative determinations of speciation parameters of the trace metals Cu, Zn, Cd and Pb in aqueous samples containing chemically heterogeneous humic substances, especially when they are present together, interacting with one another and competing for specific binding sites of the humic substances. Such determinations require fundamental knowledge and understanding of these complex interactions, gained through basic laboratory-based studies of well-characterized humic substances in model solutions. Since the chemical heterogeneity of humic substances plays an important role in the thermodynamics (stability) and kinetics (lability) of trace metal competition for humic substances, a metal speciation technique such as pseudopolarography that can reveal the special, distinctive nature of metal complexation is required, and it was therefore used in this study. A comparison of the heterogeneity parameters (Gamma) for Zn(II), Cd(II), Pb(II) and Cu(II) complexes in model solutions of Suwannee River fulvic acid (SRFA) shows that GammaCd>GammaZn>GammaPb>GammaCu, suggesting that SRFA behaves as a relatively homogeneous complexant for Zn(II) and Cd(II), whereas it behaves as a relatively heterogeneous complexant for Pb(II) and an even more heterogeneous complexant for Cu(II) under the experimental conditions used. The order of values of log K* (from the differential equilibrium function, DEF) for the trace metals at pH 5.0 follow the sequence: log K*Cu>log K*Pb>log K*Zn>log K*Cd. These results are in good agreement with the literature values. The results of this work suggest the possibility of simultaneously determining several metals in a sample in a single experiment, and hence in a shorter time than required for multiple experiments.     

Atmospheric deposition of heavy metals in Norway studied by the analysis of moss samples using neutron activation analysis and atomic absorption spectrometry

In a study of the atmospheric deposition of trace elements in different parts of Norway, samples of the mossHylocomium Splendens were analyzed with respect to 28 elements. The determination of Cu, Zn, Cd, and Pb was carried out by atomic absorption spectrophotometry, while 24 additional elements were determined by instrumental neutron activation analysis. In samples from southernmost Norway, a substantially higher concentration was found for elements such as Pb, Sb, V, Cr, Cu, Zn, As, Se, Mo, Ag, and Cd than in samples from places located in the more northerly parts of the country. The results indicate that sources which are to the south and south-west of Scandinavia, contribute significantly to heavy metal deposition in Norway.     

微波消解-ICP-MS法测定指甲中14种金属元素的含量

有益微量元素在人体的正常生命机能和各种新陈代谢中都发挥着重要的作用,同时有害重金属含量过高会对人体产生负面的影响。指甲是微量元素代谢的途径之一,因此分析指甲中元素的含量具有重要意义。本文首先建立了指甲中元素含量测定方法,采用微波消解法对指甲样品进行前处理,再使用ICP-MS测定V、Cr、Mn、Fe、Co、Cu、Zn、As、Se、Mo、Ag、Cd、Hg和Pb元素的含量,实验结果表明该方法的准确度和精密度良好。然后对同一地区100份不同个体的指甲进行了测定,结果表明指甲中有些元素的含量受性别影响,也跟环境和饮食有关。     

Determination of Essential and Toxic Elements in Vegetables from South Korea

This study reports the determination of trace essential (Co, Cr, Cu, Se, and Zn) and toxic (Al, As, Cd, Hg, and Pb) elements in greenhouse tomatoes, peppers, and cucumbers from supermarkets of Seoul, Busan, Gangneung, Daegu, Daejeon, and Gwangju, South Korea using inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectroscopy, and direct mercury analysis. The methods were validated by linearity, limits of detection and quantification, precision, accuracy, and recovery measurements that provided satisfactory results in all cases. Among the essential trace elements, Zn was found to have the highest concentrations (0.84–2.5?mg/kg) followed by Cu (0.21–0.62?mg/kg) and Cr (0.01–0.06?mg/kg). The mean concentrations (mg/kg) of the toxic elements were in the order Al?>?Pb?>?As?>?Cd?>?Hg for tomatoes and cucumbers and Al?>?Pb?>?Cd?>?As?>?Hg for peppers; all were below the permissible limits set by World Health Organization for human consumption. The estimated dietary intake, target hazard quotients (THQs), and hazard indices of the samples were within safe levels. The combined THQ values for the toxic elements in the vegetables were from 0.002 to 0.012 with significant contribution from arsenic, aluminum, cadmium, and mercury. The results of this study show that trace and toxic elements in the analyzed vegetables do not impose any serious health harmful effects for the population upon consumption.     

羊红膻中微量元素含量的测定

采用高分辨全谱直读电感耦合等离子体发射光谱仪测定了羊红膻(Pimpinella thellungianaWolff)药材地上与地下不同部位中含Cu、K、Na、Fe、Se、Mg、As、Ca、Cd、Cr、Mn、Ni、P、Pb和Zn等15种微量元素含量,并进行了比较。结果表明,重金属As和Pb几乎检测不到,K含量均高;同时也为羊红膻药理作用及临床用药提供科学依据。