Radiochemical neutron-activation analysis of uncertified ultra-trace rare earth elements in two biological certified reference materials

Radiochemical neutron activation analysis (RNAA) has been used for the determination of eight rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb, and Lu) in two Chinese certified reference materials (CRM), GBW 08503 (wheat powder) and GBW 09101 (human hair). These determinations are important for possible certification of the above mentioned ultra-trace elements, so far not certified. A simple one-step (REE)F3 precipitation was used. Chemical yields were determined for all relevant elements by means of tracer experiments. The two CRM were also analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) to compare the merits and draw-backs of these two major trace analytical techniques for these particular elements. RNAA was proven to be a reliable technique for ultra-trace analysis, especially in the certification of some ultra-trace elements.     

Calibration of gamma-ray spectrometers coupled to Compton suppression and fast pneumatic systems for the k<Subscript>0</Subscript>-standardized NAA method

A new Compton suppression system (CSS) for the gamma-ray spectrometer portion of the neutron activation analysis (NAA) was set up at the RPI/ITN. The pneumatic transfer system, SIPRA, for short-lived nuclides and cyclic irradiations was improved. A full calibration procedure of the CSS and SIPRA systems was performed. Two certified reference materials, NIST-SRM-1572 (Citrus Leaves) and NIST-SRM-1633a (Coal Fly Ash) were analyzed using the calibration factors. The CSS was instrumental in lowering the detection limits of Cr, Fe, Hg, Rb, Sr, Th and Zn by reducing background and/or spectral interference considerably. The analytical results were evaluated by comparison to the NIST certified values with deviations ranging from 2% to 8% for the above mentioned elements, except Zn ranging from 10% to 15% for biological and environmental samples, respectively.     

Intercomparison and certification of some Chinese and international food and biological matrix CRMs for several uncertified ultratrace elements by NAA

Radiochemical neutron activation analysis was used for determinationsof 8 rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in two ChineseCRMs, GBW 08503 (wheat) and GBW 09101 (hair), and Cs, Sr, Th and U in fiveNIST SRMs, 1548 (Total Diet), 1486 (Bone Meal), 8414 (Bovine Muscle), 1566a(Oyster Powder) and 1575 (Pine Needles). These determinations are for eventualcertification of above ultratrace elements so far not certified. The radiochemicalseparation scheme used in RNAA of NIST SRMs is an anion exchange followedby the co-precipitation by (REE)F 3 for U and Th, and a SrSO 4 precipitationfor Sr and Cs. For RNAA of the two Chinese CRMs, a one step (REE)F 3 precipitationwas used. Chemical yields were determined for all relevant elements by tracerexperiments. All these materials were also analyzed by ICPMS, that offeredan opportunity to compare the two major trace analytical techniques on theirmerits and drawbacks for these particular cases. RNAA is proven to be oneof the important techniques in ultratrace analysis, especially in certificationof some ultratrace elements. Determination of elements in sub-ng/g level isstill an area to be further investigated because: (1) some such elements areimportant in food and health related environmental studies, (2) many of theseelements have no (or very few) certified values in existing biological CRMs,(3) reliable techniques qualified for ultratrace analysis are needed to beestablished, and (4) sampling behavior of elements at these levels is stillnot very well known (recommended minimum sample size may not be adequate).     

ICP-AES和ICP-MS法测定光学玻璃中的15种稀土元素

采用Na₂O₂熔融分解样品,运用电感耦合等离子体发射光谱法（ICP-AES）和电感耦合等离子体质谱法（ICP-MS）测定光学玻璃中的稀土元素。采用该方法对国家一级标准物质GBW07158、GBW07159、GBW07160和GBW07161进行测定,其结果表明与标准值相符。方法选择性好、灵敏度好、定量准确,适用于光学玻璃中稀土元素的测定,结果令人满意。     

微波消解-电感耦合等离子体质谱法检测土壤中16种稀土元素

建立了微波消解-电感耦合等离子体质谱法(ICP-MS)测定土壤样品中16种稀土元素的分析方法。样品经硝酸-过氧化氢-氢氟酸消解,直接用ICP-MS测定试液中16种稀土元素。研究了ng/mL水平的Ba氧化物及轻稀土氧化物对重稀土元素的干扰程度,其中Ba和Pr的氧化物干扰较严重,不过此类干扰可通过Method编辑干扰方程得以校正。测定土壤标准物质GBW07446及GBW07451,结果与标准物质证书值一致。     

Determination of Th and U in bone ash by ICP-ion source mass spectrometry

The feasibility of ICP-ion source mass spectrometry (ICP-MS) for the determination of²³²Th and²³⁸U in bone ash was studied. Bone ash samples were further decomposed with concentrated nitric acid under pressure in PTF crucibles. The resultant solution was diluted and subjected directly to the measurement with an ICP mass spectrometer. The effects of diluting and removing matrix elements on ICP-MS measurements of these nuclides were studied. The accuracy of the determinations was evaluated with the measurement of NBS Human Lung (SRM 4351) which was originally certified for alpha activities of²³²Th and²³⁸U.     

Nickel sulfide fire assay improved for pre-concentration of platinum group elements in geological samples: a practical means of ultra-trace analysis combined with inductively coupled plasma-mass spectrometry

A method was developed for ultra-trace determination of all six platinum group elements (PGE) by inductively coupled plasma-mass spectrometry (ICP-MS). With involvement of Fe to the fusion charge compositions of the conventional NiS fire assay, a whole assay button in water may disintegrate into powder and then be dissolved with HCl. The insoluble residue was collected, and dissolved with HCl + H(2)O(2) in a sealed Teflon beaker. After the HCl + H(2)O(2) treatment the Os signal response is at least 10 times as high as that in HCl medium. With isotopic dilution method for determination of Os, all six PGE were analyzed in one sample preparation. This method was applied to a series of Chinese PGE certified reference materials, GBW 07288 to GBW 07294, and the results were found to be in reasonable agreement with the certified values. Limits of detection were assessed from the whole chemical procedure and they are 0.17 ng g(-1) for Ru, 0.01 ng g(-1) for Rh, 0.16 ng g(-1) for Pd, 0.03 ng g(-1) for Os, 0.07 ng g(-1) for Ir and 0.11 ng g(-1) for Pt. This method of precision (RSD%) was evaluated using two reference materials of GBW 07291 and GBW 07294, and it is within the range from 4.2% to 10.3%.     

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.     

电感耦合等离子体质谱法分析粉煤灰漂珠中的微量元素

建立了一种电感耦合等离子体质谱法测定粉煤灰漂珠中微量元素的方法,检出限为0.002~0.01 ng/mL,相对标准偏差为1.4%~2.5%(n=10)。用该方法分析了标准物质(GBW 07103)和德州、衡水的粉煤灰漂珠样品中的微量元素,标准物质分析结果与参考值一致,实际样品加标回收率为87.9%~105.6%。     

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-H2 O2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％...     

电感耦合等离子体质谱法测定工业纯铁中13种元素

工业纯铁样品用盐酸、硝酸、氢氟酸微波消解,消解液用水定容至100.0mL,采用电感耦合等离子体质谱法测定上述溶液中硼、镁、钙、钛、铬、镍、铜、锆、铌、锡、锑、铅、铋等13种元素的含量。采用内标法定量,13种元素的线性范围均为0.000 10%~0.015 00%,检出限(3s)为0.24~0.66μg·L^-1。用标准加入法做方法的回收试验,测得回收率为84.0%~106%。方法应用于纯铁标准样品(GBW 01401b、GBW 01402g、SRM 2167、YSBC 11247-2007)的分析,测定值与认定值相符,测定值的相对标准偏差(n=6)为0.80%~9.6%。     

微波溶样ICP-MS直接测定茶叶中15种痕量稀土元素

本文报道用ＨＮＯ３－Ｈ２Ｏ２微波溶样，不经分离富集，用标准加入ＩＣＰ－ＭＳ法，直接测定茶叶中１５种痕量稀土元素．对微波溶样和等离子体质谱测定条件进行了优化选择．在最佳实验条件下，用本法测定了国家一级茶叶标准物质ＧＢＷ０７６０５中的单一稀土元素，测得值与标准值很好吻合     

Ultratrace Elements in Terrestrial Water as Determined by High-Resolution ICP-MS

The double-focusing inductively coupled plasma-mass spectrometry (ICP-MS) was proved to be an extraordinarily sensitive analytical technique. When this ICP-MS was combined with an ultrasonic nebulizer to increase the sample introduction efficiency, the detection power of the system was enhanced even further. The detection limits of most elements attained by this technique were less than 0.1 ppt and reached as low as 1 ppq (1/1000 ppt) for several elements. Analytical results of the standard reference materials, SRM 1643c (trace elements in water) provided by the National Institute of Standards and Technology, and SLRS-2 (riverine water) supplied by the National Research Council of Canada showed that the concentration values obtained by this method were in good agreement with the certified values for all the elements examined. Although the concentration levels of elements in freshwater were in most cases lower than 1 ppm with the exception of several major elements (Na, K, Ca, Mg, Si, S, and CI), it was possible to determine around 40 ultratrace elements (Li, Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Cd, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, TI, Pb, Bi, Th, and U) with acceptable speed (less than 30 s per element) and precision (around 5% RSD) by direct sample introduction. No sample pretreatment, such as chemical separation and/or preconcentration, was necessary. It was also possible to directly determine as many as about 40 ultratrace elements in rainwater on as routine basis, although a much longer integration time (about 5 min/element) was applied because the concentration levels of elements in rainwater are far lower than those observed in river and lake water,     

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.     

碳增强效应与内标选择-电感耦合等离子体质谱法测定高温合金中痕量碲

采用电感耦合等离子体质谱法直接测定镍基高温合金中痕量碲,不需要对基体进行萃取等复杂的分离手段,通过对碳增敏剂与内标选择等因素进行优化,同时降低了多原子离子的干扰。依照质量数和ICP指数的角度选择铑为内标,校正了测定过程中信号的漂移,乙醇作为增敏剂,确定了在线的内标和增敏剂的加入模式。方法提高了痕量碲的检测灵敏度,测定下限达到0.00004% (0.4 ppm)。为了验证该方法的有效性,对高温合金的标准物质(GBW01619-01620)进行了分析,测定值与认定值吻合良好,其中结果精密度试验RSD(n=3)<10%。     

TXRF法测定松花粉中的9种生命元素

建立了微波消解前处理,全反射X射线荧光法(TXRF)同时测定松花粉中K、Ca、Ti、Mn、Fe、Ni、Cu、Zn和Rb9种生命元素含量的分析方法.松花粉原料经过微波消解前处理后,采用全反射X射线荧光光谱净计数、QXAS分析软件解谱和单一内标法进行定量分析.比较了干灰化法、湿消解法和微波消解法3种前处理方法的效果,并确立微波消解法作为样品前处理方法.用微波消解- TXRF法测定了花粉标准物质中的上述9种元素,并计算得到其仪器检出限(LLD)为0.002～0.054 mg/L,方法检出限(LDM)为0.004～0.122 mg/kg.TXRF法测定各元素的相对标准偏差(RSDs)为1.0％～5.5％.该方法操作简单、样品用量少、检出限低,对实际样品松花粉的测定结果与ICP - MS法无显著性差异.     

Analytical Quality Assurance Procedures Developed for the IAEA's Reference Asian Man Project (Phase 2)

Analytical quality assurance procedures adopted for use in the IAEA Co-ordinated Research Project on Ingestion and Organ Content of Trace Elements of Importance in Radiological Protection are designed to ensure comparability of the analytical results for Cs, I, Sr, Th, U and other elements in human tissues and diets collected and analysed in nine participating countries. The main analytical techniques are NAA and ICP-MS. For sample preparation, all participants are using identical food blenders which have been centrally supplied after testing for contamination. For quality control of the analyses, six NIST SRMs covering a range of matrices with certified and reference values for the elements of interest have been distributed. A new Japanese reference diet material has also been developed. These quality assurance procedures are summarized here and new data are presented for Cs, I, Sr, Th and U in the NIST SRMs.     

磷酸三丁酯萃淋树脂色层分离电感耦合等离子体质谱法测定富稀土样中微量铀和钍

研究了磷酸三丁酯萃淋树脂色层分离,电感耦合等离子体质谱法测定富稀土样中微量铀、钍的方法。样品经消解后,以磷酸三丁酯萃淋树脂为固定相、8 mol/L硝酸为流动相过柱分离,样品中的大部分稀土元素随流动相流出,而铀和钍则被固定相吸附,用去离子水洗脱后,再用电感耦合等离子体质谱仪测定。铀、钍的检出限分别为0.06,0.16μg/L,测定结果的相对标准偏差均小于10%(n=5),加标回收率为98%~105%。对稀土矿石标准物质进行测定,测定值与推荐值相符。该法操作简便,测定结果可靠,适于富稀土样中微量铀、钍的测定。     

Comparative evaluation of the possibilities of INAA, ED-XRF, ICP-AES and AAS in the analysis of plants

The usefulness of INAA, radionuclide ED-XRF, ICP-AES and AAS are comparatively evaluated for the determination of nutrients, essential and trace elements in various plant matrices. The comparison is performed by analysis of the following reference materials: NIST-SRM-1573, NIST-SRM-1575, NIES-1, NIES-3, NIES-6, IAEA-V-10 and Bowen's kale. The detection limits, accuracy and precision of the methods are discussed and a combination of INAA and GFAAS is recommended for analysis of plants for monitoring purposes.     

Determination of rare earth elements, thorium and uranium by inductively coupled plasma mass spectrometry and strontium isotopes by thermal ionization mass spectrometry in soil samples of Bryansk region contaminated due to Chernobyl accident

The present paper describes the inductively coupled plasma mass spectrometric (ICP-MS) determination of rare earth elements (REEs), thorium and uranium in forest, pasture, field and kitchen garden soils from a Russian territory and in certified reference materials (JLK-1, JSD-2 and BCR-1). In addition to concentration data, strontium isotopic composition of the soil samples were measured by thermal ionization mass spectrometry. The measurements contributed to the understanding of the background levels of these elements in an area contaminated due to Chernobyl accident. There was not a significant variation in the concentration of REEs at different depth levels in forest soil samples, however, the ratio of Th/U varied from 3.32 to 3.60. Though concentration of U and Th varied to some extent, the ratio did not show much variation. The value of ⁸⁷Sr/⁸⁶Sr ratio, was in the top layer soil sample relatively higher than in the lower layers.