Single-step microwave digestion with HNO(3) alone for determination of trace elements in coal by ICP spectrometry

A microwave digestion method with HNO₃ alone was conducted at a temperature as high as 250 °C for determination of 19 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Hg, and Pb) in coal jointly by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and flow injection ICP-MS (FI-ICP-MS). The validity of determination was assessed by using three standard coals, SRM 1632c, BCR 180, and SARM 19. It was found that the high-temperature digestion led to an extensive decomposition of the organic matrix and clay in coal, and no dissolved and solid carbon remained in the final solution after evaporation. Good recoveries were observed for all trace elements in three coals, with the exception of V, Rb, and Cs in high-ash SARM 19. Additionally, FI-ICP-MS combined with the present digestion without evaporation pretreatment was proved to be a rapid and efficient approach for determination of ultra-trace elements such as Se, Cd, and Hg in coal.     

Separation of trace antimony and arsenic prior to hydride generation atomic absorption spectrometric determination

A separation method utilizing a synthetic zeolite (mordenite) was developed in order to eliminate the gas phase interference of Sb(III) on As(III) during quartz furnace hydride generation atomic absorption spectrometric (HGAAS) determination. The efficiency of the proposed separation method in the reduction of suppression effects of transition metal ions on As(III) signal was also investigated. Among the volatile hydride-forming elements and their different oxidation states tested (Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), and Te(VI)), only Sb(III) was found to have a signal depression effect even at low (μg l⁻¹) concentrations under the experimental conditions employed. It has been shown that mordenite adsorbs Sb(III) quantitatively, even at a concentration of 1000 μg l⁻¹, at pHs greater than two, and also, it reduces the initial concentrations of the transition metal ions to lower levels which can be tolerated in many studies. The adsorption of Sb(III) on mordenite follows the Freundlich isotherm and is endothermic in nature.     

植物类中药材及饮片中18种重金属及有害元素研究

建立植物类中药材及饮片中铅、镉、总砷、总汞、铜、锑、锡、铬、镍、钡、锰、铊、银、铍、镝、铝、硒、钼共18种重金属及有害元素含量的检测方法和限量。样品经微波消解处理后,采用电感耦合等离子体质谱法(ICP-MS)对100批植物类中药材中的重金属及有害元素进行测定和方法研究。各元素线性关系良好,相关系数(r)均大于0.999 5,方法检出限为0.000 22~0.023 0 mg/kg,回收率为90.2%~108.7%,相对标准偏差为1.8%~4.9%。该方法准确、简便、灵敏,可为植物类中药材中重金属及有害元素的检测与控制提供方法参考。     

Evaluation of strontium isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of ciders

In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the ⁸⁷Sr/⁸⁶Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with ⁸⁷Sr/⁸⁶Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and ⁸⁷Sr/⁸⁶Sr isotope abundance ratio as original variables.     

Determination of Inorganic and Total Arsenic in Wines by Hydride Generation Atomic Absorption Spectrometry

A method is described for the determination of inorganic arsenic species and total arsenic in wines by means of hydride generation atomic absorption spectrometry (HGAAS). Simple ethanol evaporation is the only pretreatment procedure proposed for wine samples prior to direct measurement of inorganic arsenic (AsIII) and As(V) species by HGAAS. The total arsenic content is determined after microwave digestion of the wine samples. The optimal parameters for the microwave digestion procedure and the next HGAAS measurement of arsenic are established. The detection limits achieved are 0.1µgL^–1 for inorganic and total arsenic determination. The relative standard deviation for both procedures and for ten independent determinations varied between 8 and 15% for arsenic species in the range of 1–30µgL^–1. The accuracy of the procedure for total arsenic determination was proved by comparative analysis using electrothermal atomic absorption spectrometry.     

电解分离-电感耦合等离子体质谱法测定高纯铜中的杂质元素

建立了电解分离-电感耦合等离子体质谱法测定纯铜中17种杂质元素(Be,Mg,Al,P,Ti,Cr,Mn,Co,Ni,As,se,Zr,Cd,Sn,Sb,Te和Pb)的方法.通过控制电流分离基体铜,大于99%的铜沉积至阴极,各杂质元素的回收率大于90%.研究了电解后电解液的酸效应、残余铜的影响和基体效应.结果表明,选用合...     

Comparison of tungsten coil electrothermal vaporization and thermospray sample introduction methods for flame furnace atomic absorption spectrometry

Flame furnace atomic absorption spectrometry (FF-AAS) is a newly developed flame atomic absorption spectrometric technique based on arranging a flame furnace onto the top of the flame burner head. In this fundamental investigation, 25 elements were carefully tested by using either thermospray FF-AAS or tungsten coil electrothermal vaporization FF-AAS, of which 15 volatile and semi-volatile elements (Cd, Tl, Ag, Pb, Zn, Hg, Cu, Sb, Bi, Te, In, As, Se, Sn and Au) exhibited better limits of detection compared to those by conventional FAAS; however, non-volatile or refractory elements (Fe, Co, Ni, Cr, Mn, Pd, Pt, Al, Be and V) showed inferior sensitivities by the proposed methods.     

ICP-AES analysis of metal content in shell of mussel Mytilus galloprovincialis from Croatian coastal waters

Metal content in samples of shell of mussel Mytilus galoprovincialis was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The efficiency of conversion of crude samples into solution by acid digestion in an open plate and in a microwave oven was examined by use of certified reference material of marine sediment and laboratory made standards of calcite and aragonite. Influence of high Ca content matrix on emission intensities of Al, Ba, Cd, Cu, Fe, Mg, Mn, Na, Ni, Pb, Sr and Zn was observed as depression of emission signal for most of the measuring elements, ranging from 0.8% to 8%. Greater values were noted at Ba and Ni emission lines. Enhancement of signals was observed for Na and Mg lines. The determination of As, Sb, Se and Sn was performed by HG/ICP-AES. The greater abundance of Sn was found in samples collected near the Al-processing industry centre. No detectable concentrations of As, Sb, and Se were found in shell samples. Results of ICP-AES metal analysis showed that samples collected near harbours, city waste or sewage outlets, and chemical industry centres indicate the certain level of contamination. It is shown that shell analysis provides useful data in determination of marine environment status.     

Multiple microflame quartz tube atomizer: Study and minimization of interferences in quartz tube atomizers in hydride generation atomic absorption spectrometry

A systematic study was performed to evaluate the performance of a multiple microflame (MM) quartz tube atomizer (QTA) for minimizing interferences and to improve the extent of the calibration range using a batch system for hydride generation atomic absorption spectrometry (HG AAS). A comparison of the results with conventional QTA on the determination of antimony, arsenic, bismuth and selenium was performed. The interference of As, Bi, Se, Pb, Sn and Sb was investigated using QTA and MMQTA atomizers. Better performance was found for MMQTA, and no loss of linearity was observed up to 160 ng for Se and Sb and 80 ng for As, corresponding to an enhancement of two times for both analytes when compared to QTA (analyte mass refers to a volume of 200 μl). For Bi, the linear range was the same for QTA and MMQTA (140 ng). With the exception of Bi, the tolerance limits for hydride-forming elements were improved more than 50% in comparison to the conventional QTA system, especially for the interferences of As, Sb and Se. However, for Sn as an interferent, no difference was observed in the determination of Se and Sb using the MMQTA system. The use of MMQTA-HG AAS complied with the relatively high sensitivity of conventional QTA and also provided better performance for interferences and the linear range of calibration.     

Determination of trace elements by inductively coupled plasma mass spectrometry of biomass and fuel oil reference materials using milligram sample sizes

Most of the analytical techniques used to quantify elements associated with solid samples suffer from high detection limits and cannot be used for trace elements in biomass samples, particularly when only 20 mg are available for analysis. Inductively coupled plasma mass spectrometry (ICP-MS) can achieve detection limits of parts-per-trillion with liquid sample introduction by solution nebulisation. This technique was therefore tested with two standard biomass reference materials: oriental tobacco leaves and cabbage leaves. Two preparations successfully used on coal standards were used to digest the solid samples: a total digestion method (wet ashing digestion) and a partial leaching (microwave extraction). The concentrations of up to seventeen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn) were measured after the two preparations. The accuracy and sensitivity of the measurements improved when the dilution factor decreased from 5000 to 1000 and to 500. Since the proportion of mineral matter in biomass samples is small (5%), the microwave digestion extracted elements that are generally not completely extracted from coal samples (e.g. Sb). However, some trace element concentrations were below the limit of quantification after microwave extraction, even with a reduced dilution factor (As, Se and Mo) and could not be quantified. A fuel oil was also digested. The trace element concentrations were very low (between 28 and 0.1 microgram g(-1)) but acceptable results were obtained by applying a dilution factor of 100. Only six elements in the fuel oil (As, Ba, Co, Ni, Se and V) had certified or indicated values. Factors affecting the accuracy and sensitivity of the analyses are discussed. The reproducibility of analysis of the tobacco leaf standard was checked over a period of nine months by both digestion methods. The wet ashing method gave acceptable reproducibility for Ba, Cd, Co, Cu, Ga, Mn, Mo, Ni, Pb, V and Zn but poor precision for Cr, Se and Sn and showed evidence of residual chloride interference for As. The microwave extraction gave good reproducibility for As, Ba, Cd, Co, Cr, Cu, Mo, Ni and Zn but poor precision for Se and low recoveries for Ga, Mn, Sn and V. In spite of the small quantities of material analysed, it proved possible to determine the trace elements at levels down to 0.1 microgram g(-1) in the reference materials.     

马家塔矿煤层中有害痕量元素的质量分数特性

应用仪器中子活化（INAA）、电感耦合等离子体原子发射光谱（ICP AES）和原子吸收光谱（AAS）对神华集团马家塔露天矿2-2#煤层中Hg、As、Se、Pb、Be、Cr、Cd、Ni、Th、U、Mn、Mo、Co、Sb和Br共15种有害痕量元素的质量分数进行测定。结果表明，绝大部分痕量元素的质量分数都明显低于中国煤中元素质量分数的平均值，只有Hg和Mn的质量分数偏高，其中Hg的质量分数异常高；通过分析痕量元素在煤层垂向剖面上的质量分数变化特性，揭示出痕量元素在煤层中分布的非均一性,分析了影响痕量元素分布与富集的因素；通过痕量元素之间以及与黄铁矿硫、Fe、Al、Ca、P的聚类分析，研究了痕量元素之间以及与煤中不同矿物组分之间的亲和特性。     

Release and enrichment of 44 elements during coal pyrolysis of Yima coal, China

The coal samples were collected from Yima coal district, China. The pyrolysis experiments were carried out in a simulated bed quartz reactor with a heating rate of 20 °C/min. The 44 elements in raw coal and chars were determined by inductively coupled-plasma mass spectrometry instrument (ICP-MS). The release and enrichment behavior of 44 trace elements during coal pyrolysis of Yima coal was studied.

According to the transformation behaviors, chemical features and thermal features under different pyrolysis temperatures, the 44 elements can be categorized to 4 groups: light elements (Li and Be), nonmetal elements (Se, As, B, etc.), heavy metal elements (including 24 elements, Cu, V, Co, etc.) and rear earth elements (REE) (14 elements). The results showed that (1) the higher pyrolysis temperatures, the higher release ratio and release ratio of REE are very low; (2) the enrichment ratios of the elements in chars increase by the sequence of nonmetal elements < light elements < heavy metal elements < REE. The nonmetal elements, light elements and a few heavy metal elements will be emitted out from coal during coal pyrolysis and they will pollute environment.     

Comparative determination of Ba, Cu, Fe, Pb and Zn in tea leaves by slurry sampling electrothermal atomic absorption and liquid sampling inductively coupled plasma atomic emission spectrometry

The comparative determination of barium, copper, iron, lead and zinc in tea leaf samples by two atomic spectrometric techniques is reported. At first, slurry sampling electrothermal atomization atomic absorption spectrometry (ETAAS) was applied. The results of Ba and Pb determination were calculated using the method of standard additions, and results of Cu, Fe and Zn from the calibration graphs based on aqueous standards. These results were compared with the results obtained after microwave-assisted wet (nitric+hydrochloric+hydrofluoric acids) digestion in closed vessels followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination with the calibration by means of aqueous standards. The exception was lead determined after a wet digestion procedure by ETAAS. The accuracy of the studied methods was checked by the use of the certified reference material Tea GBW-07605. The recoveries of the analytes varied in the range from 91 to 99% for slurry sampling ETAAS, and from 92.5 to 102% for liquid sampling ICP-AES. The advantages of slurry sampling ETAAS method are simplicity of sample preparation and very good sensitivity. Slurry sampling ETAAS method is relatively fast but if several elements must be determined in one sample, the time of the whole microwave-assisted digestion procedure and ICP-AES determination will be shorter. However, worse detection limits of ICP-AES must also be taken into the consideration in a case of some analytes.     

乳化辅助微波消解-ICP-ORS-MS快速测定霜膏类化妆品中17种微量元素

采用乳化剂和硝酸体系微波消解样品,带八极杆碰撞/反应池(ORS)的电感耦合等离子体质谱(ICP-MS)法同时测定了霜膏类化妆品中铍、硼、铝、钛、铬、锌、砷、硒、银、镉、锡、锑、碘、钕、汞、铊和铅等17种微量元素.通过优化样品前处理和ICP-MS操作条件,降低了质谱干扰,各元素的检出限(3σ)在0.003 ～0.058 ...     

Using dried-droplet laser ablation inductively coupled plasma mass spectrometry to quantify multiple elements in whole blood

This paper describes a simple procedure for the direct analysis and determination of multiple elements in dried blood samples on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). With this technique, we simultaneously quantified 13 elements in whole blood: Be, Mn, Co, Ni, Tl, Bi, Sb, Pb, Cu, Zn, Ba, Mg, and Cd. The measured accuracies was in agreement with the Seronorm CRM certified values, except for Mn, Zn, Ba and Cd, which presented absolute differences higher than the expanded uncertainty for these elements. The within-run precision was less than 5.7% (relative standard deviation, RSD), except for the analyses of Be, and Mn (8.6% and 11.1%, respectively). The reproducibility (between-run precision) was calculated in terms of the RSD obtained for 12 analyses (i.e., four replicates of each sample in three analytical runs). Apart from Be, Mn, and Zn, the reproducibilities of all the elements listed above ranged between 4.0% and 8.5%. In contrast, for Cd, the concentration obtained was significantly different from the certified value; analyses of this element exhibited low reproducibility. Applying the matrix-matched calibration method, the accuracy for Cd measured was in agreement with both SRM966 and BCR 635; thus, matrix-matched calibration is a practical means of overcoming matrix-enhancement effects for the quantification of Cd. Sample throughput (ca. 5 min per sample) made it possible to rapidly screen a larger number of samples relative to other techniques that require time-consuming sample preparation steps (e.g., removal of a portion of the solid sample or digestion).     

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed in order to assess the behaviour of the mineral matter contained within the wood and coal samples. 32% of the biomass was extracted at the higher temperature and 12% at room temperature while only 12% of the coal was extracted at the higher temperature and 3% at room temperature. Less than 2% of the ash dissolved at the higher temperature. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials (>1000 mu) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass sample were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash. Be and Sb were not quantified in the extracts because they were present at too low concentrations; up to 40% of Mn was extracted from the biomass sample at 202 degrees C, while Se was totally extracted from the ash sample. For the forest residue, approximately 7% (at room temperature) and 45% (at 202 degrees C) of the total trace elements studied were in the extract; for the coal, approximately 8% (at room temperature) and 23% (at 202 degrees C) were in the extract. For the ash, only 1.4% of the trace elements were extracted at 202 degrees C, comprising 25% of Cd but less than 1% of Pb.     

Determination of trace elements in ambient aerosol samples

A microwave-assisted digestion procedure using HNO₃, HF, and H₂O₂ has been developed for analysis of elements in ambient particulate matter (PM). The samples are collected on cellulose filters and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The ICP-MS is calibrated with external standards, and recovery of analytes is tested with NIST SRM 1648 Urban Dust. This method has been used to quantify the airborne concentrations of a large number of elements, including Ag, As, Ba, Be, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Ni, Pb, Rb, Se, Sb, Sr, Ti, Tl, V, and Zn. For the majority of these elements, recovery of the NIST SRM is within 15% of the certified values.     

Preconcentration of trace elements on a support impregnated with sodium diethyldithiocarbamate prior to their determination by inductively coupled plasma-atomic emission spectrometry

A procedure is developed for determination of As, Co, Se, Cr, Pb, Zn, Cu, Mn, Cd, Sb, and Sn in water by ICP-AES analysis of alcohol eluates after pre-concentration of the samples. The pre-concentration is performed on a sodium diethyldithiocarbamate supported soft polyurethane foam. The sorbed elements are subsequently eluted with 1-propanol and the alcohol eluates are analysed by ICP-AES. A eight-fold concentration is achieved. An increased sensitivity in the analysis of propanol-water (30:70, v/v) solution is established as compared with aqueous solutions. The strongest effect is observed for As, Se, Pb, Cr, Sn, and Cd-increasing is more than twice. For other elements the matrix influence is by a factor of 1.45 (Cu), 1.36 (Sb), 2.08 (Zn). The method is applied to the analysis of natural water samples.     

微波消解-ICP-OES法测定汽车涂料中8种重金属

建立微波消解-电感耦合等离子体发射光谱(ICP-OES)测定汽车涂料中Pb,Cr,Se,Ba,Sb,As,Cd,Hg含量的方法。以HNO_3-H_2O_2(体积比为4∶1)混合酸消解样品,各元素分析谱线:Pb 220.353 nm,Cr 267.716 nm,Se196.090 nm,Ba 233.527 nm,Sb 217.581 nm,As 189.042 nm,Cd 228.802 nm,Hg 184.950 nm。8种元素测定结果的相对标准偏差为2.02%~12.94%(n=6);对白色、蓝色、红色汽车漆样品进行加标回收试验,Pb,Cr,Se,Ba,As,Cd,Hg,的加标回收率为81.26%~99.79%,Sb的回收率为62.43%~87.61%。该方法快速、简便,精密度、准确度较高,可用于汽车涂料中重金属含量的监控。     

ICP-AES测定南红玛瑙中剧毒元素As、Cd、Cr、Pb、Sb含量的研究

文章研究报道了电感耦合等离子体发射光谱法测定南红玛瑙中As、Cd、Cr、Pb、Sb元素含量的分析方法。通过对前处理方法的确定、分析线的选择、基体干扰方面的研究,确定了分析条件,并对比研究了标准曲线法与标准加入法在测定方面的异同。标准加入法与标准曲线法的测定结果相近,但标准曲线法的测定结果总是比标准加入法的测定结果小。在标准加入法中,各元素加标回收率在93.6％～103％之间,测定值的相对标准偏差(RSD_n=6)小于10％;在标准曲线法中,各元素加标回收率在90.2％～103％之间,各元素的相对标准偏差(RSD _n=6)也均小于10％。基体效应对标准曲线法测定存在一定的影响,但不十分明显。标准加入法可以很好地减轻基体效应的干扰,但不可大批量测定样品。因此,在分析控制质量要求允许范围内,可采用标准曲线法对南红玛瑙中剧毒元素As、Cd、Cr、Pb、Sb的含量进行测定。