全反射X射线荧光光谱法测定擦拭样品中铀的方法初探

正擦拭样品分析在核保障中具有重要意义,全反射X射线荧光光谱作为一种痕量的非破坏性分析方法,可对擦拭样品进行初步分析,为其筛选提供参考,更方便于制定后续的分析方案。本实验初步探讨了全反射X射线荧光光谱法测定擦拭样品中铀的方法,并对模拟样品进行了测定。实验方法为:配制混合标准铀溶液,加入Pb、Ni、Zr、Fe、Zn、Cr 6种杂质元素,Pb、Ni、Zr在SIMS测铀时有明显干扰,其中Pb、Ni的准确测量可为SIMS测铀微粒时提供有益信息。Fe、     

手持式XRF分析仪快速检测大气颗粒物中Cu、Zn、Pb含量

介绍了用手持式X射线荧光光谱(XRF)分析仪对大气颗粒物PM2.5中的Cu、Zn和Pb含量进行快速检测的方法。该方法用ICP-MS对滤膜样品的分析结果作为标样,建立XRF法被测元素含量——特征谱线强度工作曲线,利用此工作曲线测定大气颗粒物PM2.5中Cu、Zn和Pb的含量。该方法对大气颗粒物中Cu、Zn和Pb含量测量结果的相对标准偏差依次为5.50%、1.56%、4.71%。通过实验比对,该方法测试结果能与成都地区3月上旬浮尘天气现象相吻合。     

TBP色层分离-超声波雾化-ICP/AES法测定二氧化铀中二十一个微量杂质元素

选用TBP(磷酸三丁酯)柱上分离技术分离铀与待测元素,超声波雾化进样,ICP-AES法对二氧化铀中二十一个微量杂质元素测定的工作参数、酸度干扰、共存元素干扰、载气流量的选择、去溶温度等进行了试验研究。当取样量为250mg时,Al,Ag,Ba,Ca,Cd,Co,Cr,Cu,Fe,In,Li,Mg,Mn,Mo,Ni,Pb,Sn,Ti,V,Y和Zn的测定范围是0.2～100ng·g~(-1),回收率为94％～110％,RSD(n=8)为0.8％～6.2％。     

镎、钚、锶在黄土地下水中地球化学行为的模拟研究

结合中国的浅地层处置方针和现场实际情况，采用地球化学模式程序EQ3／6模拟研究了核素镎、钚、锶在浅地层埋藏条件下黄土地下水中的地球化学行为，其中包括核素在黄土地下水中的存在形式及地下水-黄土相互作用条件下核素存在形式的变化规律和次生矿物的生成种类和顺序等。研究结果表明：1)在现场地下水中核素的存在形式为：镎以NpO2^ 为主，次为NpO2CO3^-、：NpO2OH(aq)，分别占73．88％、19．72％和5．86％。钚以Pu(OH)5^-占绝对优势(99．68％)；锶的存在形式以Sr^2 为主，占94．84％。2)水-岩作用模拟研究结果表明：在地下水中加入研究浓度的核素镎、钚后，瞬间将生成NpO2和PuO2沉淀，同时还将生成一系列其它矿物的沉淀，主要有赤铁矿、绿泥石及磷灰石等。地下水-黄土相互作用过程中溶液中镎的浓度和存在形式变化表现为突变，在反应的初始阶段以NpO2^ 为主，占95．37％，反应进行约半小时左右时，镎的存在形式突然发生了质的变化，瞬间转变为以Np(OH)5^-为主，且含量占99．16％，但体系的pH值并没有发生突然的改变。地下水-黄土相互作用过程中钚的存在形式的变化基本上遵循渐变的规律。由反应初期以PuO2^ 为主，次为Pu(OH)5^-，逐渐过渡到Pu(OH)5^-、Pu^3 和PuSO4^ 共存，到反应后期则以Pu(OH)5^-占绝对优势，并伴有少量的Pu^3 。锶的主要存在形式在反应前后基本上未发生明显的改变，且在各种体系中均表现为以Sr^2 为主。     

核纯石墨中微量杂质元素ICP/AES法测定的研究

对核纯石墨中十八个微量杂质元素Al,Ca,Cd,Co,Cr,Cu,Fe,In,Mg,Li,Mn,Mo,Ni,Pb,Sn,V,Y和Zn的测定进行了试验研究。方法测定下限0.01μg·g~(-1)～0.04μg·g~(-1),平均回收率为94.2％～107.3％,RSD(n=8)为0.82％～6.4％。采用硝酸加高     

人发样品中微量元素的XRF分析

通过化学加入法校正吸收效应，采用X射线荧光分析法(XRF)分析人发样品，确定人发中微量元素的含量。以实际人发样品为基础，求得经基体吸收后的相对效率，拟合出相对效率与基体中重要成分Ca含量的关系式，然后用标定的系数进行人发样品中的Ca、Cu、Fe、Zn含量分析。采用此方法分析了一组人发标准物质，并与国标推荐值进行比较，结果表明测定值与推荐值符合情况良好，与国标相比偏差为Ca0．28％，Fe0．99％，Cu2．6％，Zn0；相对测量误差Ca2．2％，Fe1．7％，Cu2．2％，Zn1．1％，其灵敏度≤2．2％。表明采用XRF分析人发中微量元素含量是可行的。     

同位素稀释法测定希土元素的研究——(Ⅱ)微量希土总量的测定

本文研究了利用~(144)Ce-~(144)Pr作为示踪剂,用均匀沉淀分离并与铀试剂Ⅰ分光光度法结合的同位素稀释测定微量希土总量的方法。9倍于希土含量的Cu、Al、VO_3~-、Cr~(3 ),20倍的Ca、Zr、Ti、Fe和90倍的Zn、Pb对本法测定希土无干扰。在1g铀样中希土含量约100μg时,测定误差不超过10%。本法有可能用于工业生产中铀产品的微量希土总量的测定。     

煤炭中铅同位素分析方法研究

同位素比值是污染源解析的基础,为了探索燃煤污染源解析的可行性,本研究建立煤炭中铅同位素的分析方法。采用灰化-微波消解相结合的方式,将煤样转换为溶液状态,用PB树脂(冠醚类)萃取色层法,将铅和大量基体元素有效分离,用多接收电感耦合等离子体质谱法测定铅同位素比值。利用NIST 981标定天然铅溶液的铅同位素比值,应用建立的分析方法,测定~(208)Pb/~(207)Pb、~(206)Pb/~(207)Pb的同位素比值,相对误差小于0.03%。钠、镁、铝、铁、钛、锰等元素的去污系数均大于400。结果表明,该方法有效、可靠,测定标准煤样(NIST 1635a、NIST 1632d)、山西大同煤样和攀枝花煤样的~(208)Pb/~(207)Pb、~(206)Pb/~(207)Pb同位素比值,精密度均大于0.2%,两地煤样同位素比值变异为6%~10%,初步验证了建立全国煤炭中铅同位素比值背景数据库的可行性。     

发射光谱法测定二氧化碲中的杂质元素

作为生产放射性药物[131]碘的靶材料的二氧化碲，其纯度和所含杂质（如Al，Pb，Cu，Sb，Zn等）直接影响到[131]碘产品的核素纯度及产品质量。因此，建立一套准确、可靠的分析方法测定其所含杂质，为产品的质量控制提供准确、可靠的数据具有重要意义。     

TBP萃到-X荧光光谱法测定地质样品中的金

研究了以TBP为固体萃取剂[SE(TBP)],从HCl、HNO_3和王水(3HCl+HNO_3)溶液萃取过程中,金及其用X射线荧光光谱(XRF)测定金时的干扰元素Zn、Pb、As的行为。样品经王水浸取后,从稠状液中萃取金,是定量和选择性回收金的最有利方法.其金的分配比D_(Au)约为10~4ml/g.从HCl溶液萃取时,在金的浓度为10~(-8)-10~(-4)mol/L范围内D_(Au)值总是大于10~4,但是随着萃取温度的升高,而D_(Au)值依次降低.从20℃的5×10~5ml/g降至70℃时的9×10~3ml/g.从氯化后的HCl液溶中萃取时,我们发现铅的分配比异常地高,即D_(Pb)为10~3ml/g.这一现象可以用由于Pb(Ⅳ)与氯形成了络合物来解释.研究了用XRF测定天然样品中的金的方法.本法包括采用0.025mol/L热硫脲液从SE(TBP)中反萃取金.这样也为二次XRF测定提供了薄样品层.用25g样品进行分析,其测定限为10×10~[-9],用不同的参考物进行精度实验,结果偏差小于10％.     

Elemental analysis of mining wastes by energy dispersive X-ray fluorescence (EDXRF)

An energy dispersive X-ray fluorescence (EDXRF) tri-axial geometry experimental spectrometer has been employed to determine the concentrations of 13 different elements (K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr and Pb) in mine wastes from different depths of two mine tailings from the Cartagena-La Union (Spain) mining district. The elements were determined and quantified using the fundamental parameters method. The concentrations of Cr, Ni, Cu, Zn and Pb were compared to the values from the European and Spanish legislation to evaluate the environmental risk and to classify the wastes as inert wastes or as wastes that have to be control land-filled. The results obtained demonstrate that these wastes can be considered as inert for the considered elements, apart from the concentration levels of Zn and Pb. Whilst Zn slightly overpasses the regulatory levels, Pb mean value exceeds three to six times the value to be considered as Class I potential land-filling material.     

源激发X射线荧光测定头发中Ca、Fe、Cu、Zn、Pb的方法优化

同位素源激发X射线荧光（XRF）已广泛应用于头发中的微量元素测定。中国原子能科学研究院曾经建立了源激发X射线荧光分析技术分析头发样品,Pb的检测限（LLD）约10μg/g。本工作在原来工作的基础上优化仪器参数,降低背景信号强度,提高了灵敏度,尤其是对Pb的灵敏度,使Ca、Fe、Cu、Zn、Pb的检测限分别达到19、1.2、1.1、0.62、1.1μg。首次采用V做内标元素,取样量为0.5g,仪器的短期稳定性相对标准偏差（RSD）为0.38%,长期稳定性相对标准偏差为0.98%。     

常用稳定同位素制剂的浓集及应用

中国原子能科学研究院(简称原子能院)利用电磁法完成了国家科技支撑计划课题《科研用高纯有机试剂核心单元物质及共性关键技术的研制与开发》,利用电磁法有效分离了⁵⁴Fe、⁶⁵Cu、⁶⁴Zn、⁶⁷Zn、²⁰⁷Pb以及⁸⁵Rb、⁸⁷Rb同位素制剂,其丰度分别达到：90%、99.6%、96%、81%、90%、99%、98%。其中部分同位素试剂达到国外产品标准,部分已经应用在我国科研生产及全球卫星导航定位系统中。     

Detection of heavy metals in water samples by laser-induced breakdown spectroscopy combined with annular groove graphite flakes

The use of laser-induced breakdown spectroscopy(LIBS) for the analysis of heavy metals in water samples is investigated. Some factors such as splashing, surface ripples, extinction of emitted intensity, and a shorter plasma lifetime will influence the results if the water sample is directly measured. In order to avoid these disadvantages and the ‘coffee-ring effect', hydrophilic graphite flakes with annular grooves were used for the first time to enrich and concentrate heavy metals in water samples before being analyzed by LIBS. The proposed method and procedure have been evaluated to concentrate and analyze cadmium, chromium, copper, nickel, lead,and zinc in a water sample. The correlation coefficients were all above 0.99. The detection limits of 0.029, 0.087, 0.012, 0.083, 0.125, and 0.049 mgl~(-1) for Cd, Cr, Cu, Ni, Pb, and Zn,respectively, were obtained in samples prepared in a laboratory. With this structure, the heavy metals homogeneously distribute in the annular groove and the relative standard deviations are all below 6%. This method is very convenient and suitable for online in situ analysis of heavy metals.     

In situ analysis of human teeth by external PIXE

The elemental profiles of the enamel, cementum and caries of human teeth were analysed by the external proton induced X-ray emission studies. Ten elements namely P, Ca, V, Mn, Fe, Cu, Zn, As, Sr and Pb were estimated in the present study. P and Ca were found to be the major elements whereas all other elements were found in trace level. It was observed that the respective concentrations of elements namely P, Ca, Fe, Zn and Pb in enamel are more than those in cementum. Concentration of P ranged between 6.37% and 25% whereas Ca ranged between 12.94% and 43.36%.     

用计算机模式识别法和PIXE法研究人发中元素在食管癌诊断中的作用

用ＰＩＸＥ方法对华北地区的４１４例食管癌、食管上皮重度增生病人和正常人的头发样品中的１２种元素进行了测定。经过ｔ检验发现，癌症病人与正常人比较，１０种元素（Ｓｉ，Ｓ，Ｃａ，Ｃｒ，Ｍｎ，Ｆｅ，Ｎｉ，Ｃｕ，Ｐｂ，Ｓｒ）有显著差异；食管上皮重度增生病人和正常人比较，９种元素（Ｓｉ，Ｐ，Ｓ，Ｃａ，Ｃｒ，Ｍｎ，Ｆｅ，Ｎｉ，Ｚｎ）有显著差异，说明头发中微量元素的变化先于人体内食管的癌变。用计算机模式识别法对上     

Size-fractionated aerosol composition during an intensive 1997 summer field campaign in northern Finland

A 12-stage small deposit area low pressure impactor (SDI) was used to collect size-fractionated aerosol samples during an intensive 1997 summer field campaign in northern Finland. The samples were analyzed for over 20 elements by PIXE, and some “difficult” elements such as As and Se could be quantified. The sea-salt and crustal elements had essentially a unimodal coarse size distribution with geometric mean aerodynamic diameter (GMAD) of about 4–5 μm. In one third of the samples, S showed only one mode in the fine size range, with GMAD of 0.4–0.5 μm. In the other samples, this fine S mode broke up into two modes, with GMADs of 0.3 and 0.6 μm, respectively. V, Zn, As, Se and Pb were mainly present in a single submicrometer mode, with GMAD of 0.4–0.5 μm for V and Se, and slightly larger (i.e., 0.6 μm) for the other three elements. The highest concentrations of S, V, Ni, Cu, Zn, As, Se and Pb were encountered in the SDI sample which had been collected in the period 14–16 July. During this sampling, the air masses came in from the west, but had recirculated over northern Scandinavia and passed over the Kola peninsula.     

Trace element load in cancer and normal lung tissue

Samples of malignant and benign human lung tissues were analysed by two complementary methods, i.e., particle induced X-ray emission (PIXE) and total reflection X-ray fluorescence (TRXRF). The concentration of trace elements of P, S, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Se, Sr, Hg and Pb was determined in squamous cancer of lung tissue from 65 people and in the benign lung tumour tissue from 5 people. Several elements shows enhancement in cancerous lung tissue of women in comparison to men, i.e., titanium show maximum enhancement by 48% followed by Cr (20%) and Mn (36%). At the same time trace element concentration of Sr and Pb are declaimed by 30% and 20% in women population. Physical basis of used analytical methods, experimental set-up and the procedure of sample preparation are described.     

EDXRF无标样分析未知样品含量的算法研究

针对未知样品能量色散X射线荧光分析（energy dispersive X-ray fluorescence analysis, EDXRFA）方法开展无标样分析,通过测量Ti、Fe、Ni、Cu、Zn、Sr、Sn、Pb单元素标样,得到Rh靶材原级谱中K_α峰的相干与非相干散射峰强度比值R,并建立R与对应单元素标样有效原子序数的关系,得到Z_eff-R的拟合曲线。求解未知样品基体时,测量未知样,得到其R,将R代入Z_eff-R拟合曲线得到未知样有效原子序数,再通过基本参数法迭代计算其质量衰减系数。利用Ti、Fe、Ni、Cu、Zn、Sr、Sn、Pb单元素标样刻度仪器获取G_i参数,求解未知样品基体时用于相应元素的基本参数迭代。为验证算法可靠性,采用本算法分析15个国家土壤标准样品,结果表明,Ti、Fe、Ni、Cu、Zn元素的计算含量与标准含量接近,部分低含量元素受到散射本底等因素影响,含量误差较大。结果表明,该方法能够用于现场能量色散X射线荧光分析。