Glancing incidence x-ray fluorescence spectrometry based on a single-bounce parabolic capillary

Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this instrumental setup to analyze a Si single crystal and a 50 nm HfO_(2) single-layer film deposited on a Si substrate.

Elemental and proximate analysis of coal by x-ray fluorescence assisted laser-induced breakdown spectroscopy

Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.

Analysis of the injection layer of PTCDA in OLEDs using x-ray photoemission spectroscopy and atomic force microscopy

Through the investigation of the sample surface and interface of 3, 4, 9, 10-perylenetetracarboxylic dianhydride （PTCDA）/indium-tin-oxide （ITO） thin films using atomic force microscopy, it has been found that the surface is complanate, the growth is uniform and the defects cover basically the surface of ITO. Furthermore, the number of pinholes is small. The analysis of the sample surface and interface further verifies this result by using x-ray photoemission spectroscopy. At the same time, PTCDA is found to have the ability of restraining the diffusion of chemical constituents from ITO to the hole transport layer, which is beneficial to the improvement of the performance and the useful lifetime of the organic light emitting diodes （OLEDs）.

Apply X-Ray Fluorescence and γ-Ray Spectroscopy to Analyze Igneous and Sedimentary Environmental Samples of Al-Atawilah (Al-Baha), Saudi Arabia

Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rocks is necessary to estimate the exposure of the population to the radiation. Many types of rocks are used in building and industries, thus the radiation detection is important, it provides a baseline map of levels of the radioactivity in the study region. The purpose of this study is to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) (if found) in thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The samples were collected and prepared during 2018/2019, and analyzed with a good experimental instrument (High energy resolution γ-ray spectroscopy with HPGe detector), also these rock samples were analyzed with X-ray fluorescence to subdivided these rocks based on the major oxides proportions contained of each sample. The mean activity concentrations of naturally radionuclides were found in the igneous rock samples varied depending on the type of the igneous rock. For sedimentary rock samples, the activity concentrations were found high for quartz sandstone sample, which may be due to its high proportion of SiO2 and K2O. The estimated mean values of absorbed dose rate are within the permissible limit value. The findings indicate high dose level values in granite (rhyolite) and most of diorite (andesite) igneous rock samples while gabbro (basalt) igneous rock samples (except for one sample) record low levels of dose rate. All sedimentary rock samples have low dose rate (except for the quartz sand-stone sample).

Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression

The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.

A method for correcting characteristic X-ray net peak count from drifted shadow peak

To correct spectral peak drift and obtain more reliable net counts,this study proposes a long short-term memory(LSTM)model fused with a convolutional neural network(CNN)to accurately estimate the relevant parameters of a nuclear pulse signal by learning of samples.A predefined mathematical model was used to train the CNN-LSTM model and generate a dataset composed of distorted pulse sequences.The trained model was validated using simulated pulses.The relative errors in the amplitude estimation of pulse sequences with different degrees of distortion were obtained using triangular shaping,CNN-LSTM,and LSTM models.As a result,for severely distorted pulses,the relative error of the CNN-LSTM model in estimating the pulse parameters was reduced by 14.35%compared with that of the triangular shaping algorithm.For slightly distorted pulses,the relative error of the CNN-LSTM model was reduced by 0.33%compared with that of the triangular shaping algorithm.The model was then evaluated considering two performance indicators,the correction ratio and the efficiency ratio,which represent the proportion of the increase in peak area of the two characteristic peak regions of interest(ROIs)to the peak area of the corrected characteristic peak ROI and the proportion of the increase in peak area of the two characteristic peak ROIs to the peak areas of the two shadow peak ROI,respectively.Ten measurement results of the iron ore samples indicate that approximately 86.27%of the decreased peak area of the shadow peak ROI was corrected to the characteristic peak ROI,and the proportion of the corrected peak area to the peak area of the characteristic peak ROI was approximately 1.72%.The proposed CNN-LSTM model can be applied to X-ray energy spectrum correction,which is of great significance for X-ray spectroscopy and elemental content analyses.

ICP-AES法和原子荧光法检测硫熏处理对山药中重金属的影响

目的:研究硫黄熏蒸对山药中重金属含量的影响,为评估硫黄熏蒸的安全性及山药加工工艺提供科学依据。方法:选取13批不同产地的硫黄对山药进行熏蒸处理,使用微波消解法对样品进行前处理,并通过电感耦合等离子体原子发射光谱法与原子荧光光谱分析法定量分析硫黄及熏蒸前后山药中汞(Hg)、砷(As)、铜(Cu)、镉(Cd)和铅(Pb)的含量。结果:13批硫黄中Pb、As、Hg含量偏高。硫黄熏蒸后,山药中Pb含量普遍上升,且部分样品中As、Hg和Cu含量亦有增加。结论:硫黄熏蒸可能导致重金属元素从硫黄迁移到山药中,因此应制定严格的硫黄熏蒸工艺规范,确保山药的安全性和质量,减少对人体健康的潜在风险。

内部质控样芹菜中总砷含量的不确定度评定

《检验检测机构资质认定能力评价检验检测机构通用要求》(RB/T 214—2017)4.5.15中鼓励检验检测机构在检验检测出现临界值、内部质量控制或客户有要求时,报告测量不确定度。按《食品安全国家标准食品中总砷及无机砷的测定》(GB 5009.11—2014)第二法原子荧光光谱法测定内部质控样芹菜中的总砷,并对其进行测量不确定度评定。结果显示芹菜中总砷的含量为0.516 mg·kg^(-1),其扩展不确定度为0.046 mg·kg^(-1),证书提供的标准差为0.021 mg·kg^(-1),换算成Z比分数,|Z|=0.33,测试结果满意。

Studies on the Interaction Between Vanillin and β-Amyloid Protein via Fluorescence Spectroscopy and Atomic Force Microscopy

β-Amyloid（Afl） plaques and intracellular neurofibrillary lesions in the brain are markers of Alzheimer＇s disease（AD）. The ability to safely decrease Aft concentrations is potentially important as a preventive strategy for AD. The interactions between vanillin and Aft polypeptide were investigated via fluorescence spectroscopy and atomic force microscopy（AFM）. The results of fluorescence and synchronous spectroscopies illustrate that the intrinsic fluorescence of tyrosine（Tyr） residues in Aβ1-42 aggregates can be quenched strongly upon the formation of vanil- lin-Aβ-42 complex. Thioflavine T（ThT）-induced fluorescence changes indicated that Aβ1--42 aggregates could be disaggregated by vanillin, and the AFM images of Aβ1-42 enunciated the depolymerization of Aβ1-42 aggregates by vanillin in a dose-dependent manner. Vanillin may be a potential pharmacological agent for the treatment of AD.

液相色谱—原子荧光光谱联用法测定海鱼粉中甲基汞含量的不确定度评定

本文评估了用液相色谱法—原子荧光光谱法测定海鱼粉中甲基汞的不确定度。对测试过程中不确定度的来源进行分析,并对各组分的不确定度进行计算。结果表明,当海鱼粉中甲基汞的含量为0.670 mg/kg,扩展不确定度为0.034 mg/kg(k=2)。

锗元素测定方法综述

锗在国防工业、航空航天和通信等领域中具有战略性意义,锗含量的测定对于保证材料质量和满足国际标准至关重要。对锗含量测定方法的多种技术进行了综述,包括分光光度法、原子荧光光谱法、原子吸收光谱法、电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法以及滴定法等。在每种检测方法的介绍中,详细探讨了方法的原理、前处理步骤以及应用范围,并分别总结了各方法的优势和不足。最后,强调了锗含量测定方法的意义,特别是在满足出口监管和促进科学研究方面的作用。同时对锗元素的测定方法进行了展望,为未来的发展提供了参考方向。

甘草中20种无机元素的测定及对有害元素的健康风险评估

目的测定甘草中无机元素含量,并对重金属及有害元素进行污染分析及健康风险评估。方法采用电感耦合等离子体质谱法及原子荧光光谱法测定甘草中的无机元素含量及数据分析。通过计算样品中Pb、Cd、As、Hg和Cu5种重金属及有害元素的单向污染指数和综合污染指数对其进行安全性评价,通过计算每日最大可耐受摄入量(maximum tolerable daily intake,EDI)、靶标危害系数(target hazard quotients,THQ)和致癌风险(carcinogenic risk,CR),对甘草中5种重金属元素和有害元素进行健康风险评估,计算出甘草中各重金属的推荐重金属限量值(maximumresiduelimit,MRL)。结果得到的各无机元素在各自范围内线性关系良好(0.9969≤R2≤0.9996),样品稳定性、重复性、加标回收率及仪器精密度良好;Cr、Mn、Ni、Cu、Rb、Sr和Ba元素含量较高,并且各样品间各元素含量具有一致性和差异性;主成分分析中22个样品得到5个主成分,累计方差贡献率达84.308%,确定Ga、V、Cs、Se、Co、As、U、Ni、Cd和Hg是甘草的特征无机元素;相关性分析结果与主成分分析结果基本一致;健康风险评估结果显示甘草样品均对暴露人群无明显健康危害,其致癌风险也可忽略不计。结论本研究所建立的方法可有效进行甘草无机元素的测定及来源判别,并为甘草健康风险评估提供了科学依据。

SBR与生物油恢复老化SBS改性沥青性能及机理研究

【目的】苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene-butadiene-styrene block copolymer,SBS)改性沥青老化后存在基质沥青硬化、脆化及SBS聚合物有所降解的问题,用传统再生方式难以有效恢复老化SBS改性沥青的性能。为有效恢复老化SBS改性沥青的路用性能,采用丁苯橡胶(styrene-butadiene rubber,SBR)与生物油对老化SBS改性沥青进行复合再生。【方法】首先,通过室内模拟老化试验制备得到了老化SBS改性沥青,采用高速剪切仪在老化SBS改性沥青中掺入SBR和生物油,得到复合再生沥青;然后,对再生后的沥青进行三大指标测试及高低温流变性能测试;最后,通过红外光谱、原子力显微镜和荧光显微镜试验探究SBR和生物油再生沥青的机理。【结果】SBR和生物油复掺后得到的再生沥青的综合性能更优,再生沥青的复数剪切模量G*随再生剂掺量的增加呈降低趋势。再生后沥青的刚度大幅减小,老化沥青的柔韧性得到恢复,应力耗散能力得到提升,脆性得到降低,低温性能得以显著改善。SBR和生物油复合再生可以补充老化SBS改性沥青的轻质组分,混掺SBR和生物油后沥青质和胶质的比例有所降低,轻质组分对蜂状结构的蜡结晶有抑制作用。再生沥青的荧光物质大幅增加,且分布更密集,老化SBS改性沥青的韧性和黏度得到显著恢复。【结论】恢复老化SBS改性沥青性能的SBR与生物油的推荐掺量分别为6%、5%。该研究为老化SBS改性沥青混合料的再生提供了理论依据。

水环境中锑分析检测方法的研究进展

锑(Sb)是广泛存在于水环境中的一种重金属,不断被证实对人和动植物等有慢性毒性和致癌风险。在监测和治理水环境中的Sb污染方面,建立快速、高灵敏度的Sb检测分析方法至关重要。重点阐述了分光光度法、原子荧光光谱法(AFS)、电感耦合等离子体质谱法(ICP-MS)、电感耦合等离子体原子发射光谱法(ICP-OES)、原子吸收光谱法(AAS)和电化学分析法在Sb分析检测中的相关研究及应用进展,探讨了水环境中Sb检测存在的问题和面临的挑战,如检测方法灵敏度低、间接测定Sb耗时且不准确、还原剂昂贵且有毒等。此外,对Sb检测未来的发展方向进行展望。未来Sb检测趋势是发展电化学分析方法。通过电极修饰和纳米材料设计提高传感器性能,如碳基材料、金属纳米颗粒和硅基材料。有机配体、纳米复合材料和裸电极的功能化可增强灵敏度和选择性,促进传感器小型化。未来Sb检测将迈向小型化、芯片化和快速化。

原子荧光光谱法测定化探样品中分散元素锗含量

采用原子荧光光谱法测定化探样品中分散元素锗含量,对影响测定锗含量的几个主要因素,如仪器负高压、灯电流、溶液介质、载流、还原剂以及前处理方式等进行了系统的分析研究,确定了最佳的测定条件,完善了原子荧光光谱法测定化探样品中锗含量的分析方法,取得了满意的结果。

原子荧光光谱法在环境监测领域中的应用进展

原子荧光光谱法具有操作简单、灵敏度高、检出限低、稳定性好的优势,常被应用于砷、硒、汞、锑等重金属元素的测定,是一种较为理想的重金属定量分析方法。本文主要概括了近年来原子荧光光谱法在我国水质监测、土壤监测、空气监测等环境领域中的应用进展。同时,简要介绍了该技术在其他领域中的应用进展,可为后续原子荧光光谱技术的进一步发展和应用以及监测人员对各个领域中重金属的监测工作提供理论参考。

原子荧光光谱法检测食用鱼中汞、砷含量

目的:建立原子荧光光谱法同时测定食用鱼中汞、砷含量的方法。方法:采用微波消解法对样品进行预处理,原子荧光光谱法同时测定食用鱼(淡水鱼、海水鱼)中汞、砷含量,分析其检测结果。结果:汞在0~10.0μg·mL^(-1)时线性关系良好,砷在0~40.0μg·mL^(-1)时线性关系良好,相关系数> 0.999。汞的检出限在2.50~3.83μg·mL^(-1),回收率为94.1%~99.0%,精密度为2.9%;砷的检出限在2.30~3.68μg·mL^(-1),回收率为93.3%~99.2%,精密度为2.0%。对比发现食用海水鱼中汞、砷含量显著高于淡水鱼(P <0.05)。结论:原子荧光光谱法操作简单、检测灵敏度较高,可同时测定食用鱼汞、砷含量。

微波消解-原子荧光光谱法测定栀子中的砷和汞

[目的]对中药材栀子中的2种危害较大的重金属元素砷和汞含量进行测定,建立栀子中砷和汞元素的检测方法。[方法]样品经微波消解处理后,采用原子荧光光谱法测定栀子中砷、汞含量。[结果]栀子中砷含量为0.1045 mg/kg,汞含量0.0141 mg/kg,均低于2020版《中国药典》检查项下重金属限量规定。[结论]该方法高效、准确可靠、精密度高,为中药中汞、砷的质量控制和监测提供了简单、快速的测试手段。

原子荧光光谱法测定五氧化二磷中的砷

研究了采用原子荧光光谱法测定五氧化二磷中的砷,确定了酸介质、酸度、还原剂浓度、预还原剂和掩蔽剂。结果表明:方法在1.0~50.0μg/L范围内线性良好,相关系数r>0.999,检出限为0.064μg/L,定量限为0.21μg/L;8次样品分析结果的相对标准偏差(RSD)为1.94%,加标回收率为92.87%~101.30%,检验结果与DDTC银盐法无明显差异。该法操作更便捷,所用试剂少,是一种测定五氧化二磷中砷含量的可靠方法。

采用原子荧光光度法测定磷酸及磷铵中的砷含量

采用AFS-11B型原子荧光光度计对磷酸及磷铵中砷含量测定开展应用研究。对测定酸度、还原剂浓度、原子化温度测定条件进行了优化,通过优化的条件采用标准曲线法进行验证。实验表明,该方法准确度高,测定结果稳定可靠,适用于磷酸及磷铵产品中砷含量的测定。