The determination of calcium concentrations in human milk with energy dispersive X-ray fluorescence

This work reports on an alternative method for the determination of element concentrations in human milk. Energy dispersive X-ray fluorescence (EDXRF) spectrometer with an annular Am²⁴¹ and Fe⁵⁵ sources was applied for the analysis of human milk samples. A sample preparation method suitable for the EDXRF analysis was described. The results were presented in Table 1. Energy dispersive X-ray fluorescence technique has been successfully used for the determination of calcium and other elements in human milk. For this reason, the experimental approach and the analytical method used in this study appear adequate for the purpose and can therefore be exploited for similar investigations.     

能量色散X荧光分析中元素间效应的蒙特卡罗模拟

针对能量色散X荧光分析(EDXRF)技术中元素间效应实验研究的难点问题,采用蒙特卡罗方法对基于Si（PIN）探测器的EDXRF系统建立模拟模型,并对模拟微束软X射线注量谱建立了高斯展宽算法。对Fe-Ni样品进行模拟计算,表明经该算法展宽后的注量谱与实测K系特征X射线谱吻合度较高,并得到了各元素特征X射线归一计数与元素含量关系曲线,结果表明该方法可自行校正EDXRF中元素间效应,获得准确的元素K系特征X射线谱理论强度。     

能量色散X荧光分析中元素间效应的蒙特卡罗模拟

针对能量色散X荧光分析(EDXRF)技术中元素间效应实验研究的难点问题,采用蒙特卡罗方法对基于Si（PIN）探测器的EDXRF系统建立模拟模型,并对模拟微束软X射线注量谱建立了高斯展宽算法。对Fe-Ni样品进行模拟计算,表明经该算法展宽后的注量谱与实测K系特征X射线谱吻合度较高,并得到了各元素特征X射线归一计数与元素含量关系曲线,结果表明该方法可自行校正EDXRF中元素间效应,获得准确的元素K系特征X射线谱理论强度。     

An alternative method for the determination of element concentrations in schizophrenic, lung cancer and leukaemia patient bloods

Concentration of the elements present in schizophrenic, lung cancer and leukaemia patients’ bloods were determined using energy-dispersive X-ray fluorescence (EDXRF) method. EDXRF spectrometer with an annular and sources was applied for the analysis of blood samples. A sample preparation procedure suitable for the EDXRF, the experimental approach, analytical method used in this study and the results were presented. EDXRF technique has been successfully used for the determination of elements present in blood.     

改进型M-P神经网络在能量色散X荧光分析测定铅锌矿元素含量的应用研究

以新疆西天山铅锌矿样品的Cu,Fe,Pb等元素X荧光测量数据做训练样本,McCulloch-Pitts神经网络(M-P神经网络)为基础,基体效应为依据,建立新的神经网络模型对Zn进行定量预测。结果预测值与测量值的相对误差在<5%。此方法可较准确,快速的应用于现场X荧光测定,为X荧光光谱信息修正提供一种新方法。     

种群算法在能量色散X荧光重叠谱拟合中的应用

在能量色散X荧光光谱分析中,常用的闪烁探测器如NaⅠ(Tl)探测器的能量分辨率都不高,均在8%左右。能量分辨率低下往往对谱数据分析带来较大的难题,特别是在高本底低计数的情况下剥离仪器谱重叠峰会受到很大限制,越是重叠严重的峰越是无法剥离,进而无法分辨峰值和峰面积,更无法进一步对元素进行定性定量分析。为此,结合遗传算法和免疫算法的优势建立新的种群算法应用在重叠谱分析上,该算法以欧式距离为进化的判断依据,以最大相对相似误差值为迭代准则进行迭代。利用高斯函数模拟不同重叠程度的仪器谱图,将种群算法应用在重叠峰分离和全谱模拟中,峰道址偏差在±3道以内,峰面积偏差不超过5%,证明该方法在能量色散X荧光重叠谱分析中有较好的效果。     

Energy - dispersive X - ray diffraction of the ammonium - halides under pressure

Abstract

The structure of the ammonium halides NH₄X (X = Cl, Br, I) has been studied under pressure up to 40 GPa by energy dispersive X-ray diffraction using synchrotron radiation. Equations of state and a discussion on the possible structure of phase V will be presented.     

X射线荧光光谱分析样品烧增量的影响及校正

研究采用熔融法制备矿石样品时出现的烧增量问题,建立新的校正方法.硫化物矿的烧增量有百分之几十,它改变基体组成,造成基体校正的错误,新方法先将具有烧增量的样品转换成具有烧失量的新样品,然后用差减法校正烧失量,用理论影响系数法校正基体效应,求得新样品的结果,最后再换算回原样的结果.此方法以铜精矿为实验对象,比较差减法和重量...     

Improvements of portable energy dispersive X-ray fluorescence instrument: Resolution with Silicon Drift Detector,measurements stability using pyroelectric sources,and adaptation for space use

An energy dispersive X-ray fluorescence instrument has been developed to be used for space exploration. In particular, the electronic readout has been redesigned to withstand the radiation environment of space and improve the energy resolution down to 121.17 eV using an Silicon Drift Detector (SDD). Besides, the instrument uses pyroelectric sources as excitation sources. We include a renormalization to reduce measurement fluctuation from 25.2% to 3.7%. A peak search algorithm has been implemented based on calibration to improve accuracy and reduce possible aging drift effects.     

Review of in situ X-ray fluorescence analysis technology in China

In the past two decades, the in situ X-ray fluorescence (XRF) technology has been developed rapidly in China, which is mainly due to the rapid development of China's economy and the great demand for rapid qualitative and quantitative analysis of elements in geological exploration, environmental protection, and industrial process analysis. In this article, the development of in situ XRF analysis technology in China is reviewed from three aspects, namely in situ XRF analyzers, in situ XRF analysis technology, and applications of in situ XRF analysis technology. The in situ XRF analyzers are divided into four generations, and the technical characteristics of each generation of analyzers are discussed from the perspectives of X-ray excitation source, detector, electronic circuit unit, and digital signal processing. The progress of X-ray spectrum analysis, matrix effect correction, and correction of uneven effect and humidity effect is reviewed. The representative applications of XRF analysis technology in geological and mineral survey, environmental pollution investigation, cultural relic identification, and alloy analysis are introduced.     

Determination of elements in some lichens growing in Giresun and Ordu province (Turkey) using energy dispersive X-ray fluorescence spectrometry

The concentration of five different elements in six lichens species of different regions in Giresun and Ordu (Turkey) was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied to the elemental analysis of lichens. An annular 50 mCi ²⁴¹Am radioactive source and an annular 50 mCi ⁵⁵Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li)detector which has a 147 eV full-width at half-maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, and barium.     

Qualitative and quantitative analysis of pathological and non-pathological human bone using radioisotope X-ray fluorescence technique

Pathological and non-pathological human elbow bone samples were collected from one male human patient and one female human patient who were undergoing treatment in our University Research Hospital. Pathological and non-pathological human elbow bone samples were analyzed by means of energy-dispersive X-ray fluorescence spectrometry by using standard additions method. Experimental results are presented and discussed in this work.     

不同激发方式对能量色散X射线荧光法测铀的影响

针对能量色散X射线荧光法测铀过程中存在自激发效应对测量结果产生干扰的问题及以往测铀仅使用放射性同位素源作为激发源的测量限制,利用微型X射线对铀矿样品进行自激发效应测量,并分别将109Cd,241Am,微型X光管三种不同激发源测量铀矿样品的结果进行比较分析。结果表明,自激发效应产生的特征X射线峰面积计数仅为有源条件的0.01%以下,属统计涨落范畴,对测量结果的干扰可忽略不计;109Cd源由于其特征射线能量22.11和24.95 keV均在L_α吸收限能量21.75 keV附近,激发光电截面最高,相应的荧光产额也高,故109Cd源相比于241Am源对铀元素的激发效率更高;241Am源测量误差明显大于109Cd源的测量误差,原因是铀的L系能量特征峰与241Am源特征射线26.35 keV的散射峰能量区叠加,造成实测谱线本底偏高;X光管作激发源的铀矿样品中铀含量与化学分析结果之间的误差在10%以内,仅为同位素源激发X射线荧光分析误差的一半,且X光管激发谱峰面积计数值明显大于源激发条件下的峰面积计数,说明X光管作激发源的测铀质量优于源激发模式。     

便携式EDXRF分析仪测定土壤中镍元素的含量预测模型研究

论述了便携式能量色散X射线荧光分析仪在土壤重金属元素镍测定过程中,基体效应对测量结果的影响,提出以样品散射的X管的标识靶线(钨靶L_α1线)作为比较标准的特散比校正模型,并在此基础上结合吸收元素校正法对基体效应进行校正,以此建立的含量预测模型,相关系数为0.999,剩余标准差为2.541。利用该模型对土壤标样中镍含量进行测量,与标准值比较,其平均相对误差为3.90%,且精确度较高。     

基于EDXRF的土壤中痕量镉的快速检测方法研究

对于土壤中重金属元素的检测,传统的化学分析方法测试周期长,前处理复杂,使用的强酸还会对环境造成二次污染,能量色散X射线荧光光谱法具有无损、快速、前处理简单、仪器轻便等优点,特别适合现场快速检测,但用该方法对镉元素进行检测时,通常用到的K系特征线能量较大,普通能谱的检出限较高。基于能量色散X射线荧光光谱技术,研究了土壤中痕量重金属镉的快速检测方法,通过选择合适的仪器部件,搭建仪器测试系统,综合考虑待测元素的谱峰强度和相对强度,对仪器结构和测试条件进行优化。研究表明,峰强度随着管电流的升高基本上是线性增加的,而相对强度则没有明显的变化,对于镉的测试,在光管条件允许的情况下选择尽可能大的管电流进行测试,之后,综合考虑镉的峰强度和相对强度随滤光片厚度以及管电压的变化情况,使用理论标准偏差确定测试最优条件为：管电压为55 kV,管电流为48 μA,滤光片为1.25 mm钼片;测试时间会影响测试结果的相对标准偏差,在测试时间小于500 s时,峰强度的相对标准偏差随着测试时间的增加是降低的,在测试时间大于500 s时,峰强度的相对标准偏不再有明显的变化趋势,由于测试结果的相对标准偏差越小,测试结果的短期精密度越好,仪器的重现性就越好,因此测试时间最终选择为500 s;样品测试条件也会对测试结果产生影响：随着测试薄膜厚度的增加,镉的峰强度和相对强度均是降低的,根据实验结果,最终选择厚度为12.5 μm的聚酯膜进行测试;镉的峰强度和相对强度随着样品质量的增加而增加,在样品质量大于3 g时,镉的峰强度随样品质量的增加变化比较缓慢,相对强度则没有明显的变化,选择样品的质量大于3 g进行测试;随着含水量的增加,镉的峰强度和相对强度均会略有降低,因此水分会对测试结果产生影响,对土壤样品的测试应该风干或烘干。使用以上经过优化的测试条件,用国家标准样品和电感耦合等离子体质谱法定值的样品绘制工作曲线,线性相关系数可达0.993;使用镉含量为1.12 mg·kg-1的国家标准样品GSD-10测试11次,测试的结果的标准偏差为0.09,相对标准偏差为8.22%;用高纯二氧化硅测试方法检出限,可达0.16 mg·kg-1,小于国标一级土壤的限值;测试实际样品,并与电感耦合等离子体质谱法测试的结果进行对比,测试结果的一致性较好。通过对仪器结构和样品测试条件进行优化,基于能量色散X射线荧光光谱法对土壤中痕量重金属镉的检出限有了很大的降低,对污染地区土壤镉的快速筛查及大面积测定意义重大。     

便携式X射线荧光光谱分析仪测定土壤中重金属

应用NITON XL3t600型便携式X射线荧光谱分析仪对土壤中主要重金属污染物Cu,Zn,Pb,Cr和As进行了测试。结果表明,Cu,Zn,Pb,Cr和As元素的最低检出限分别为:23.96,11.69,8.58,19.23,6.24mg.kg-1;对土壤成分分析标准物质GSS-5进行5次重复测定,准确度在96%～102%之间,RSD在1.0%～7.6%范围内,表明仪器对于土壤中较高浓度重金属检测准确度和精密度良好;田间进行原位检测,相对标准偏差均小于20%,与国标方法检测结果相比,准确度在55%～119%之间。通过实验室测试和田间原位检测,验证了便携式X射线荧光谱分析仪检测土壤中重金属元素有较好的准确度和精密度,适用于土壤中重金属的快速检测。     

热解析富集-能量色散X射线荧光光谱法对溶液中汞的测定

搭建热解析富集装置对溶液中的汞富集后进行检测,可以提高X射线荧光测试的灵敏度.整个测试过程如下:样品中的汞在高温下发生热解析,经过滤膜时被选择性吸附,在使用光谱仪测试后,最终计算出样品中汞的含量.在热解析管路中加入白云石增加停留时间,可以降低汞的热解还原温度,在使用汞稳定化剂的条件下,只需加热到600℃就可以实现汞的解...     

原位活体骨铅X射线荧光光谱分析

报道了应用X射线荧光光谱技术在中国本土获得的普通人群原位人体活体骨铅数据,发表了中国大陆普通居民的胫骨和根骨活体骨铅浓度及其研究结果。采用Pb的K系谱线进行了原位活体分析人胫骨和根骨骨铅含量。普通人群样本中所测骨铅含量加权平均值在0.4～22.7μg.(g骨矿物质)-1之间,不确定度在7.0～12.5μg.(g骨矿物质)-1之间,平均最小检出限20.3μg.(g骨矿物质)-1。在污染调查区居民中发现骨铅最高可达73.9μg.(g骨矿物质)-1。