Geochemical analysis of marine sediments using fused glass disc by X-ray fluorescence spectrometry

A method was developed for content determination of Na, Mg, A1, Si, P,S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sediment samples using fused glass disc by X-ray Fluorescence spectrometry. Calibration was made using marine sediment certified reference materials and the synthetic standard samples prepared by mixing several marine sediments with stream sediment and carbonate standard samples in different proportions. The matrix effect was corrected using theoretical alpha coefficients, experience coefficients and the scattered radiation as the internal standard （for the trace elements）. The accuracy of the method was evaluated by analysis of certified reference materials GBW07314, GBW07334 and GSMS6. The results are in good agreement with the certified values of the standards with RSD less than 2.60%, except for Y, Cr, Ga, Ce, La, Nb, Rb, and V with RSD less than 9.0% （n=12）.

X-ray fluorescence spectrometry determination of open-hearth furnace slag by pressed powder briquetting

A rapid analysis method of determining content of eight compounds of open-hearth furnace slag was developed using X-ray fluorescence spectrometry and pressed powder briquettes. Matrix effect was corrected using theoretical alpha coefficient. Grains-size effect was eliminated by optimized sample preparation technique parameters. Mineral effect was corrected with standard curve of specially made standard samples. The analysis results of TiO2, TFe, SiO2, MgO, Al2O3, CaO, MnO and P2O5 in slag samples showed that both precision and accuracy are comparable with that of chemical method.

Determination of Content of Eight Elements in Metal Coating Smeared on Waste Plastics by X-ray Fluorescence Spectrometry

X-ray fluorescence spectrometry was used to detect the content of eight elements in metal coating smeared on waste plastics,and effects of sample cups,elements in plastic substrate,and interaction of elements in metal coating on detection results were analyzed. The results show that the RSD of the method used to detect element content in the metal coating smeared on the waste plastics ranged from 0.008% to 0.044%; the determination range of the eight elements was 0.002%-52.0%,and their detection limit ranged from 0.0002% to 0.0008%. The determination results of X-ray fluorescence spectrometry were consistent with that of ICP-AES. The method can provide technical support for the determination of damage and pollution caused by metal coating smeared on waste plastics.

Quantitative Analysis of FeMo Alloys by X-Ray Fluorescence Spectrometry

A quantitative analysis method of molybdenum in FeMo alloys by X-ray spectrometry using borate fusion technique was compared with that with pressed pellet. The complete pre-oxidation of FeMo alloys for the preparation of homogeneous fused discs was achieved by employing an automated fusion machine equipped with specially designed O2-blowing nozzles, which used lithium tetra-borate as flux with the addition of lithium nitrate (LiNO3) as oxidizer. The calibration curves of Mo and Fe were used in the quantitative analysis of standard materials and unknown plant samples with satisfactory accuracy and precision, utilizing the corrections of the matrix effects and line overlap. It was confirmed that the newly proposed method of preparing fused glass discs of FeMo alloys can replace the conventional wet chemical analyses requiring the labor intensive and time consuming procedure.

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.

Scanning electron microscopy coupled with energydispersive X-ray spectrometry for quick detection of sulfuroxidizing bacteria in environmental water samples

Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.

泡沫塑料富集-火焰原子荧光光谱法测定土壤及水系沉积物中微量铊

建立了一种采用硝酸-氢氟酸溶解样品,泡沫塑料富集-火焰原子荧光光谱法测定土壤及水系沉积物中微量铊的方法,并优化了实验条件,在取样0.5 g,解吸体积10 mL时,方法检出限为0.012 mg/kg,定量限为0.04 mg/kg。

Possible Relevance of the Allende Meteorite Conditions in Prebiotic Chemistry: An Insight into the Chondrules and Organic Compounds

The study of the mineral and organic content of the Allende meteorite is important for our understanding of the molecular evolution of the universe as well as the ancient Earth. Previous studies have characterized the magnetic minerals present in ordinary and carbonaceous chondrites, providing information on the evolution of magnetic fields. The interaction of organic compounds with magnetic minerals is a possible source of chemical diversity, which is crucial for molecular evolution. Carbon compounds in meteorites are of great scientific interest for a variety of reasons, such as their relevance to the origins of chirality in living organisms. This study presents the characterization of organic and mineral compounds in the Allende meteorite. The structural and physicochemical characterization of the Allende meteorite was accomplished through light microscopy, powder X-ray diffraction with complementary Rietveld refinement, Raman and infrared spectroscopy, mass spectrometry, scanning electron microscopy, and atomic force microscopy using magnetic signal methods to determine the complex structure and the interaction of organic compounds with magnetic Ni-Fe minerals. The presence of Liesegang-like patterns of chondrules in fragments of the Allende structure may also be relevant to understanding how the meteorite was formed. Other observations include the presence of magnetic materials and nanorod-like solids with relatively similar sizes as well as the heterogeneous distribution of carbon in chondrules. Signals observed in the Raman and infrared spectra resemble organic compounds such as carbon nanotubes and peptide-like molecules that have been previously reported in other meteorites, making the Mexican Allende meteorite a feasible sample for the study of the early Earth and exoplanetary bodies.

微波消解—氢化物—原子荧光光谱法测定大米中痕量硒

采用微波消解 -氢化物 -原子荧光光谱法对大米中痕量硒进行了消解、测定。建立了大米微波酸消解的最佳分析条件 ,确定了原子荧光光谱仪的参数设置和最佳氢化反应条件。检测限 0 .0 0 8ng/mL ,测定标准物质大米粉 (GBW 0 85 0 2 )中硒的含量 ,其结果与证书值相吻合 ,精密度 2 .1% ,回收率 93.8%～ 10 4 .1%。

原子荧光法测定食品总砷的前处理方法探讨

通过研究两种不同混酸(硝酸-高氯酸和硝酸-高氯酸-硫酸)对小麦粉、蔬菜粉、海藻粉进行前处理,原子荧光法对其总砷进行测定。结果表明:测定小麦粉、蔬菜粉中总砷时,两种前处理方法得出的结果基本一致;对海藻粉样品,使用高沸点硫酸处理,消化效果明显提高,使用硫酸消化海藻样品测定结果通过了国际能力验证(比利时IMEP 112)的检验。小麦粉、蔬菜粉样品中总砷的存在形式主要以无机砷形态存在,低沸点酸适合砷存在形态相对简单的样品,但对于富含有机砷的藻类样品,只有使用高沸点硫酸进行处理,藻类中有机砷才能充分分解转化为无机砷,从而为原子荧光光谱仪准确测定。

铝土矿和赤泥的X射线荧光光谱测定

本法采用日本理学3070EX射线光谱仪,使用熔融法制备样品,测定了铝土矿、生料、熟料以及赤泥中铝、硅、铁、钙、钛、钾、镁和钠等8个元素。

金汞齐富集冷原子荧光测汞法的研究

本文介绍了一种用于测定汞的金汞齐富集热解系统。研究了该系统与冷原子荧光测汞仪联用的工作条件和干扰,在最佳条件下的检出下限为4×10^(-13)克汞,分析周期3分钟,相对标准偏差2.5%(1.5×10^(-9)克汞)。

佛手瓜中几种维生素含量的测定

据维生素的特性 ,用无机溶剂或有机溶剂从佛手瓜中提取维生素B2 、维生素C和叶酸 ,并用荧光分光光度法、比色法测定它们的含量。结果为 :维生素B2 0 .15 6mg/ 10 0g、维生素C4 .0 7mg/ 10 0g、叶酸 0 .36mg/ 10 0g。

不同矿物药材中重金属、有机质和浸出物含量的分析

【目的】系统测定和分析8种矿物药材生品和煅制品中的重金属、有机质和浸出物含量,为矿物药材的质量控制提供科学依据。【方法】以自然铜、花蕊石、鹅管石、海浮石、银精石、金精石、金礞石和青礞石为供试矿物药材,采用原子吸收光谱法、原子荧光光谱法测定其重金属（Cu、Pb、Cd、Cr、Hg、As）含量,采用重铬酸钾氧化-外加热法测定有机质含量,按照药典中规定的浸出物测定方法测定浸出物含量。【结果】矿物药材样品中重金属、有机质和浸出物的含量在不同药材间以及同种药材的生品与煅制品间差异显著,其中8种矿物药材生品中Cu、Pb、Cd、Cr、Hg、As含量分别为1.58～10 646.35,7.16～267.95,1.87～79.15,0.00～32.52,0.004～0.799,7.62～134.54 mg/kg,煅制品中的含量分别为2.21～2 357.54,6.50～135.47,2.00～16.23,0.00～28.22,0.000～0.177,4.56～192.81mg/kg;8种矿物药材生品和煅制品中有机质含量分别为2.10～115.32和0.89～9.36 g/kg;8种矿物药材生品和煅制品中水提冷浸法获得的浸出物含量分别为0.25%～4.99%和0.50%～3.24%,水提热浸法分别为0.37%～3.92%和0.25%～3.26%,醇提冷浸法分别为0.23%～1.45%和0.16%～1.29%,醇提热浸法分别为0.20%～1.47%和0.19%～1.53%。【结论】重金属、有机质、浸出物含量在8种矿物药材中差别很大,且各指标含量之间并不具有特定的规律性,需进一步结合相应的药理试验结果,才能科学合理的制定出矿物药材的质量标准。

原子荧光快速测定环境水样中的砷

本方法采用氢化物-原子荧光方法测定环境水样中的砷,经反复试验证明,本方法是测定环境水样中砷污染的快速、灵敏、具有推广意义的方法。结果表明,本方法检出限为0.07μg/L,相对标准偏差为3.5%,回收率为91%-105%。

X射线荧光光谱法测定铁矿石中各组分

采用高温熔融对铁矿石试样进行预处理,以消除矿物效应。X射线荧光光谱法测定铁矿石中TFe,Al2O3,CaO,MgO,SiO2,P,Cu,Pb,Zn,As,Sn,Ti,Mn时,应用SUPERQ软件中的理论系数法、经验系数法对各组分进行校正,计算出各组分分析曲线的校正常数和拟和精度,得到最佳工作曲线,取得满意的结果。

酸对原子荧光光度法测定砷的影响

①目的探讨用氢化物－非色散型原子荧光法测定砷时酸的影响。②方法配制含不同浓度强酸（ＨＮＯ３，Ｈ２ＳＯ４，ＨＣＩＯ４）的砷溶液，在不同最终体积中测量砷的荧光强度。③结果当浓度较高时，上述３种酸对砷的回收率均有影响。Ｈ２ＳＯ４的回收率最低，显示了最大的抑制性，其次为ＨＮＯ３，再次为ＨＣｌＯ４；影响取决于溶液中酸的浓度而与酸的总量无关。④结论降低溶液中酸的残留量可消除对砷回收的影响。

氢化物原子荧光法测定含铀岩石中微量硒

本文介绍了氢化物原子荧光法测定含铀岩石中微量硒的方法。测定下限为０．０１μｇ／ｇ，测量精度（２×１０－７）ＲＳＤ为６．６３％。方法灵敏度高、快速、操作简便。本方法也适用于一般岩石样品中微量硒的测定。

原子荧光光谱法测定祛斑霜中的汞

采用盐酸处理祛斑霜样品,用还原气化-原子荧光光谱法测定其中的汞,研究了仪器测定条件和不同样品处理方法对测定的影响。结果表明样品处理方法对测定结果影响不大;此方法的加标回收率在96%以上,相对标准偏差为2 5%;此方法具有快速、简便和灵敏的特点。

最优化理论解浓度校正方程

在X 射线荧光光谱定量分析中 ,要进行试样基体效应的数学校正 .针对常用的浓度校正法中的不一致问题 ,提出了最优化处理方法 .结果表明 ,最优化方法能减少浓度校正法在回归中带来的某些误差 。