Determination of Ultra-Trace Platinum,Palladium, Ruthenium,Rhodium, and Iridium in Rocks and Minerals by Inductively Coupled–Plasma Mass Spectrometry Following Nickel Sulfide Fire Assay Preconcentration and Open Mixed Acid Digestion

Platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and osmiun (Os) are platinum-group elements with similar physic-chemical properties, and have important applications in geochemistry and environmental chemistry. However, due to their low abundance and inhomogeneous distribution in natural ores as well as the nugget effect, the accurate determination of the platinum-group elements has been a challenge for geological analysis. In this work, self-prepared and purified sodium carbonate (NiCO₃) instead of commercial nickel oxide (NiO) was used as the fire assay collector in order to greatly reduce the reagent blank and method detection limits. In addition, the fuming time of HClO₄ was strictly controlled at 10?min and a high sensitive method was developed for the simultaneous determination of ultra-trace Pt, Pd, Ru, Rh, and Ir in minerals by inductively coupled plasma-mass spectrometry (ICP-MS) following preconcentration with the nickel sulfide fire assay. Under the optimized conditions, the linear ranges of Pt, Pd, Ru, Rh, and Ir were between 0 and 100?ng mL^?1, with correlation coefficients exceeding 0.9997. The detection limits were 0.015, 0.056, 0.014, 0.004, 0.012?ng mL^?1 (for 10?g sample) for Pt, Pd, Ru, Rh and Ir, respectively. The developed method was successfully applied to analyze Chinese Certified Reference Materials (CRMs) GBW07288, GBW07289, GBW07290, GBW07291, GBW07292, GBW07293, GBW07294, GBW07101, GBW07102 and GBW07201 and the determined values were in good agreement with the certified values. The relative standard deviations (n?=?5) of Pt, Pd, Ru, Rh and Ir were between 3.42% and 6.87% for the determination of GBW07291.     

Determination of mercury, selenium, bismuth, arsenic and antimony in human hair by microwave digestion atomic fluorescence spectrometry

A novel method for determination of Hg, Se, Bi, As and Sb based on microwave digestion followed by continuous flow vapour generation atomic fluorescence spectrometry was developed. The digestion for Hg was based on a two stage digestion involving HNO(3) and H(2)O(2), whilst for the hydride forming elements a common digestion using HCl and H(2)O(2) was found to be the most effective. The instrumentation and chemistry were optimised in order to provide the best accuracy and precision. The method detection limit for hair samples was found to be 0.2 ng g(-1) for Hg and between 2 and 10 ng g(-1) for the hydride forming elements. The atomic fluorescence detector showed excellent linearity over the concentration ranges studied with linear correlation co-efficients between 0.99984 and 0.99997. To validate the accuracy of the method a human hair certified reference material (GBW 0706) was analysed and excellent agreement with the certified value was obtained for all elements.     

王水溶样-电感耦合等离子体质谱（ICP-MS）法测定地质样品中的金

称取10.00 g样品放于马弗炉中700℃条件下焙烧后,加入约60 mL王水,盖上表面皿于低温电热板(1000 W)溶解40 min,加入5 mL动物胶(20 g/L),搅拌均匀后加入等体积的水,抽滤,滤液定溶至500 mL,分液后以10 ng/mL的Rh为内标建立了王水溶样-电感耦合等离子体质谱(ICP-MS)法快速测定地质样品中金的分析方法。方法适用于检测0.1~10μg/g品位的矿石样品,对国家一级标准物质GBW07209、GBW07808、GBW07809、GBW07300进行12次测定,其相对标准偏差RSD均小于5%,相对误差RE均小于2%。方法具有简单快速等优势,在实际应用中得到满意的结果。     

微波消解-氢化物发生-原子荧光光谱法测定中药材中痕量砷

采用微波消解法用硝酸-过氧化氢(3+1)溶液消解样品,以硫脲及抗坏血酸混合溶液作为预还原剂,利用氢化物发生-原子荧光光谱法测定中药材当归、丹参、甘草、三七和黄芪中痕量砷的含量。在盐酸(3+97)溶液中加入溶于20g.L-1氢氧化钾溶液中的10g.L-1硼氢化钾溶液使与溶液中砷离子反应生成氢化物。分析中采用载气流量为800mL.min-1。砷的质量浓度在12μg.L-1以内与其对应的荧光强度呈线性关系,方法的检出限(3s/k)为0.020μg.L-1。应用此法对国家标准物质人发(GBW 09101)进行分析,测定值与认定值一致。     

低空白镍锍试金预富集中子活化分析测定地球化学标准物质中的铂族元素

研究了镍锍试金预富集中子活化分析测定岩石样品中的铂族元素。纯化捕集剂氧化镍,大大降低了化学分离全流程铂族元素的空白。取样量为50g时,所需溶剂各元素的空白值为(ng/g):Pt<0.05、Pd<0.05、Os<0.01、Ru<0.05、Rh<0.05、Ir=0.002。用平面锗探测器测定Rh使测定下限降低了两个数量级,对几种国标地球化学标准物质的测定结果与推荐值基本符合。     

石墨炉原子吸收光谱法测定矿石中铂、钯、铑、铱

矿石样品铂、钯、铑和铱经铅试金富集,所得金属合粒用硝酸-盐酸溶解,用石墨炉原子吸收光谱法测定矿石样品中铂、钯、铑和铱的含量。在优化的石墨炉工作条件下测得:铂的质量浓度在20～150μg.L-1、钯在15～120μg.L-1、铑和铱在6～100μg.L-1范围内与其吸光度呈线性关系,检出限(3s/k)依次为4.6,4.0,1.5,1.5μg.L-1。方法用于分析了2种矿石国家标准物质(GBW 07341、GBW 07342),测定结果与认定值相符。方法的回收率在87.6%～105.5%之间。测定值的日内和日间相对标准偏差(n=7)分别在2.8%～3.6%和3.5%～4.7%之间。     

电感耦合等离子体质谱(ICP-MS)法测定农产品样品中6种痕量元素

建立了电感耦合等离子体质谱(ICP-MS)法测定果蔬类、大米等农产品样品中痕量元素的方法。样品通过HNO3-H2O2混酸体系微波消解,以Rh作为内标溶液消除基体干扰,在仪器最佳条件下测定植物样中镉、铅、铬、铜、镍、锌6种痕量元素。方法的检出限为0.002~0.5μg/g;相对标准偏差(RSD)为0.84%~7.4%。利用所建立的方法测定了大米(GBW10010)、小麦(GBW10011)、芹菜(GBW10048)、大葱(GBW10049)4种标准物质,分析结果均在参考值范围内。方法简单、快速、准确,适用于批量样品中多元素的同时测定。     

ICP-AES determination of trace rare earth elements in environmental and food samples by on-line separation and preconcentration with acetylacetone-modified silica gel using microcolumn.

A novel method of online microcolumn separation and preconcentration coupled to inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of acetylacetone-modified silica gel as packing material was developed for the determination of trace rare earth elements (REEs) in environmental and food samples. The main parameters affecting online separation/preconcentration, including pH, sample flow rate, sample volume, elution and interfering ions, have been investigated in detail. Under the optimized operating conditions, the adsorption capacity values for Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu were 25.65, 23.23, 24.01, 19.40, 22.89, 23.77, 24.40, 23.96, 25.58, 25.15, 24.86, 22.75, 16.05, 24.13, 26.51 and 27.93 mg g(-1), respectively. Detection limits (3sigma) based on three times standard deviations of the blanks by 8 replicates were in the range from 48 pg mL(-1) for Lu to 1003 pg mL(-1) for Sm. With 90 s preconcentration time and 10 s elution time, the enrichment factor was 10 and the sample frequency was 28 h(-1). The precisions (RSDs) obtained by determination of a 250 ng mL(-1) (n = 8) REEs standard solution were in the range from 1.7% for Y to 4.4% for Sm. The proposed method was successfully applied to the determination of trace REEs in pig liver, agaric and mushroom. To validate the proposed method, we analyzed three certified reference materials (GBW07401 soil, GBW07301a sediment, and GBW07605 tea leaves). The determined values were in a good agreement with the certified values. The method is rapid, selective, sensitive and applicable to the determination of trace REEs in biological and environmental samples with complicated matrix effects.     

微波消解样品-电感耦合等离子体原子发射光谱法测定竹叶中9种必需微量元素

竹叶样品置于聚四氟乙烯罐中,加入硝酸及过氧化氢后在微波消解仪中按设定程序加热消解。所得样品溶液定容至25mL后用电感耦合等离子体原子发射光谱法测定其中铬、锌、镍、钴、铁、硼、锰、铜和锶等9种元素的含量。9种元素的质量浓度在0.05～2.00mg.L-1范围内与其发射强度呈线性关系,方法的检出限(3s)在0.04～0.50μg.g-1之间。方法应用于分析了一种杨树叶标准物质(GBW 07604),所得9种元素的测定结果与证书值相符。方法的回收率在87.0%～107.6%之间。     

Determination of lanthanoids and some heavy and toxic elements in plant certified reference materials by inductively coupled plasma mass spectrometry

The possibilities of inductively coupled plasma mass spectrometry (ICP-MS) (choice of isotopes, instrument optimisation) for the determination of lanthanoids, and some heavy and toxic elements in plants are discussed. A variety of plant certified materials (NIST-SRM-1515, NIST-SRM-1547, NIST-SRM-1573a, NIST-SRM-1575, GBW 08504, GBW 08505) are analysed and the elements: As, Be, Bi, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Ga, Gd, Ho, La, Lu, Nd, Ni, Pb, Pr, Rb, Sm, Sr, Th, Te, Th, Tl, U, V, Y, Yb and Zn are determined. The comparison with certified values and literature values indicated that ICP-MS is a very promising method for the instrumental determination of Be, lanthanoids, Th and U and other elements at ng/g level in plants.     

Simultaneous determination of methylmercury and ethylmercury in rice by capillary gas chromatography coupled on-line with atomic fluorescence spectrometry

A comprehensive method for simultaneous determination of methylmercury (MeHg) and ethylmercury (EtHg) in rice by capillary gas chromatography (GC) coupled on-line with atomic fluorescence spectrometry was developed. The experimental conditions, including the pyrolyzer temperature and flow rates of the make-up gas and sheath gas, were optimized in detail. The absolute detection limits (3sigma) were 0.005 ng as Hg for both MeHg and EtHg. The relative standard deviation values (n=5) for 10 ng Hg/mL of MeHg and EtHg were 2.5 and 1.3%, respectively. The method was evaluated by analyzing 2 certified reference materials (DORM-2 and GBW08508), and the determined values of MeHg and total mercury concentrations were in good agreement with the certified values. In addition, the recoveries of MeHg and EtHg spiked into a rice sample collected from Jiangsu province in China were 86 and 77%, respectively. The proposed method was applied to analysis of MeHg and EtHg in 25 rice samples cultivated in 15 provinces of China. In all samples, MeHg was detectable and no EtHg was found. The MeHg contents in rice samples ranged from 1.9 to 10.5 ng/g, accounting for 7-44% of the total mercury measured.     

氟化电热蒸发／等离子体原子发射光谱直接测定植物试样中硼的研究

本文提出了用聚四氟乙烯悬浮体制样电热蒸发－ＩＣＰ－ＡＥＳ直接测定植物试样中新方法，研究了上述元素在该技术中的粒度效应，基效应和存在下的蒸发行为，在优化的实验条件下，本法测定Ｂ的检出限为１．２ｎｇ／ｍｌ，ＲＳＤ为４．２％，该法有简便，灵敏和分析前试样无需进行化学处理的优点，已应用于生物试样的直接测定，分析结果与参考值吻合。     

Interferences removal for cadmium determination in samples with complex matrices by hydride generation coupled with non-dispersive atomic fluorescence spectrometry.

An intermittent on-line concentration and separation system coupled with HG-AFS was developed to eliminate serious interferences from Cu2+, Pb2+ and Zn2+ on the determination of cadmium. In the present method, the interferences from common coexisting ions, such as Cu2+, Pb2+, Zn2+, Fe3+ and Ni2+, were greatly reduced. Under the optimized conditions, a detection limit of 3 pg ml(-1) (3sigma, n=11) and a precision of 1.9% RSD for 1 ng ml(-1) of Cd were obtained. The method was successfully applied to the determination of cadmium in a series of Chinese Geological Reference Materials (SRMs) and GBW01621 ferronickel alloy using simple aqueous standard calibration technique. The results obtained were in good agreement with the certified values.     

The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g(-1) for Pd, 0.4 ng g(-1) for Rh and 4.3 ng g(-1) for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and "soluble" phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km(-1) for Rh to 70.5 ng km(-1) for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter.     

X射线荧光光谱法测定硅石中主次量元素组分

以Li_2B_4O_7、LiBO_2和LiF(质量比为45∶10∶5)为混合熔剂,NH_4NO_3为氧化剂,LiBr为脱模剂,熔融制作样片,采用硅质砂岩、石英岩标准样品和配制标准样品作为校准样品,建立了熔融制样-X射线荧光光谱法(XRF)测定硅石中主次量成分(SiO_2、Al_2O_3、TFe_2O_3、MgO、CaO、K_2O、MnO、TiO_2、P_2O_5)的快速分析方法。对样品制备以及分析测试过程中的条件进行了优化,在最优条件下,对标准样品(GBW03112、GBW07835)进行重复测定,相对标准偏差RSD2%。同时对3个混合配制的硅石标准样品进行分析,结果与参考值无显著性差异。     

Solution cathode glow discharge induced vapor generation of mercury and its application to mercury speciation by high performance liquid chromatography-atomic fluorescence spectrometry

A novel solution cathode glow discharge (SCGD) induced vapor generation was developed as interface to on-line couple high-performance liquid chromatography (HPLC) with atomic fluorescence spectrometry (AFS) for the speciation of inorganic mercury (Hg(2+)), methyl-mercury (MeHg) and ethyl-mercury (EtHg). The decomposition of organic mercury species and the reduction of Hg(2+) could be completed in one step with this proposed SCGD induced vapor generation system. The vapor generation is extremely rapid and therefore is easy to couple with flow injection (FI) and HPLC. Compared with the conventional HPLC-CV-AFS hyphenated systems, the proposed HPLC-SCGD-AFS system is very simple in operation and eliminates auxiliary redox reagents. Parameters influencing mercury determination were optimized, such as concentration of formic acid, discharge current and argon flow rate. The method detection limits for HPLC-SCGD-AFS system were 0.67 μg L(-1) for Hg(2+), 0.55 μg L(-1) for MeHg and 1.19 μg L(-1) for EtHg, respectively. The developed method was validated by determination of certified reference material (GBW 10029, tuna fish) and was further applied for the determination of mercury in biological samples.     

Enhanced sensitivity for Os isotope ratios by magnetic sector ICP-MS with a capacitive decoupling Pt guard electrode

A magnetic sector ICP-MS with enhanced sensitivity was used to measure Os isotope ratios in solutions of low Os concentration (approximately 1 ng g(-1) or less). Ratios with 192Os as the basis were determined, while the geologically useful 187Os/188Os ratio was also measured. Sample introduction was via the traditional nebuliser-spray chamber method. A capacitive decoupling Pt shield torch was developed "in-house" and was found to increase Os signals by approximately 5 x under "moderate" plasma conditions (1050 W) over that found during normal operation (1250 W). Sensitivity using the guard electrode for 192Os was approximately 250-350,000 counts s(-1) per ng g(-1) Os. For a I ng g(-1) Os solution with no guard electrode, precisions of the order of 0.2-0.3% (189Os/192Os and 190Os/192Os) to approximately 1% or greater (186Os/192Os, 187Os/192Os and 187Os/188Os) were found (values as 1 sigma for n = 10). With the guard electrode in use, ratio precisions were found to improve to 0.2 to 0.8%. The total amount of Os used in the acquisition of this data was approximately 2.5 ng per measurement per replicate. At the higher concentration of 10 ng g(-1), precisions of the order of 0.15-0.3% were measured (for all ratios), irrespective of whether the shield torch was used. Ratio accuracy was confirmed by comparison with independently obtained NTIMS data. For both Os concentrations considered, the improvement in precision offered by the guard electrode (if any) was small in comparison to calculated theoretical values based on Poisson counting statistics, suggesting noise contributions from other sources (such as the sample introduction system, plasma flicker etc). At lower Os concentrations (to 100 pg g(-1)) no appreciable loss of ratio accuracy was observed, although as expected based on counting statistics, poorer precisions of the order of 0.45-3% (1 sigma, n = 5) were noted. Re was found to have a detrimental effect on the precision of Os ratios involving 187Os, indicating that separation of Re and Os samples is a necessary pre-requisite for highly accurate and precise Os isotope ratio measurements.     

电感耦合等离子体原子发射光谱法测定五氧化二钒中19种杂质元素

采用盐酸消解五氧化二钒样品及其中所含可溶性杂质,再以无水碳酸钾与硼酸高温熔融不可溶性杂质,然后以盐酸溶解熔块,合并溶液后以用电感耦合等离子体原子发射光谱法测定杂质元素铌、锆、钛、钨、硅、铝、钼、钴、铬、镍、铜、铅、镉、砷、磷、铁、锰、钙和镁的含量。试验了基体元素和共存元素对测定的干扰,优化各元素的分析谱线,运用同步背景校正消除基体影响。19种元素的检出限在10～225μg.L-1之间,背景等效浓度在5～150μg.L-1之间。方法用于分析五氧化二钒样品,测定结果与其它化学分析方法测定值一致;分析五氧化二钒标准样品(GSBH 42015-96)的测定值与标准值相一致。     

186Os和188Os双同位素溶液的制备及其中Os同位素丰度与含量的标定

在核反应堆中辐照高纯铼金属带 ,185Re和187Re通过 (n ,γ)反应后 ,经 β衰变产生186Os和188Os ,用H2 O2 和H2 SO4 将Re带溶解并同时将186Os和188Os蒸馏出 ,首先用 2 0 %NaOH溶液吸收 ,然后再将碱吸收液重新蒸馏 ,最后将186Os和188Os混合同位素保存在 2 5 %HCl介质中 ,用负离子热电离质谱仪 (NTIMS)标定其含量及同位素丰度。结果表明 ,91.4mg的高纯铼金属带 ,在辐照的累积通量为 1.32× 10 18n/cm2时 ,可产生Os 8.46 μg ,其186Os和188Os的同位素丰度分别为 6 0 .89%和 38.6 3%     

Analysis of uranium and isotopic ratio measurement in fish and marine invertebrates from the North Adriatic Sea by inductively coupled plasma mass spectrometry

Uranium analysis in fish, echinoderms and shellfish samples collected in the north part of the Adriatic Sea is presented. The aim of the work was to evaluate uranium concentrations in samples of this kind, and also to investigate possible contamination from depleted uranium (DU) in consequence of the war operations previously conducted in that area. DU contamination was checked by measuring the (235)U/(238)U isotope ratio. The samples were dissolved according to the EPA 3052 procedure, and the determinations were performed by inductively coupled plasma mass spectrometry (ICP-MS), optimized in order to perform isotope ratio measurements with good precision. The method was validated by evaluating the recovery from spiked samples; results in the range 93-107% were obtained. The isotope ratio measurement was evaluated in terms of accuracy and precision by analyzing the certified reference materials IAEA 326 and GBW 07305, and good agreement with the certified values was obtained here also. The concentration of uranium was higher in invertebrate samples than in fish (0.3-2 microg/g of U vs. 0.05-0.1 microg/g, respectively). The isotope ratio measurements for all the samples gave values very similar to the natural ratio, permitting exclusion of the presence of DU.