Analysis of macro-constituents in steels by PGAA

The determinatin of the concentration of major steel forming elements in 2–5 g steel samples by PGAA and reference to synthetic standard or single comparator is presented. The relative standard deviation is approximately 5%. The analysis time is about 60 min per sample.     

Errors,PGAA, and metrology

Analytical chemists are scientific scavengers, using any available physical phenomenon to determine the composition of materials. Accuracy, unlike mere reproducibility, depends on understanding the measurement process, most usefully by stressing it until it bends. The use of neutron capture gamma rays for analysis involves some issues not encountered in conventional neutron activation analysis which, when understood, extend the utility and reinforce the value of nuclear methods of elemental analysis. These methods are being increasingly recognized as tools for SI-traceable metrology.     

Increasing the dynamic range for the analysis of boron in PGAA

Prompt gamma activation analysis (PGAA) is especially sensitive for elements with high neutron-capture cross sections, like boron, which can be detected down to a level of ng/g. However, if it is a major component, the high count rate from its signal will distort the spectra, making the evaluation difficult. A lead attenuator was introduced in front of the HPGe-detector to reduce low-energy gamma radiation and specifically the boron gamma rays reaching the detector, whose thickness was found to be optimal at 10 mm. Detection efficiencies with and without the lead attenuator were compared, and it was shown that the dynamic range of the PGAA technique was significantly increased. The method was verified with the analyses of stoichiometric compounds: TiB₂, NiB, PVC, Alborex, and Alborite.     

Prompt gamma neutron activation analysis (PGAA): recent developments and applications

Journal of Radioanalytical and Nuclear Chemistry - Prompt gamma neutron activation analysis has become an important part of the analytical toolkit, practiced at several research reactors worldwide....     

Mass spectra of alkylbenzenesulphonates by filament heated in-beam electron impact

Summary Sodium benzenesulphonate gives a strong disodium sulphonate ion peak and cluster ions of tri- and tetrasodium sulphonates by our devised EI-MS. Sodium dodecylbenzenesulphonates also give molecular plus sodium ion peaks and clear fragmentation patterns comparable with those of corresponding hydrocarbons. The results suggest that hard-type and soft-type alkylbenzene sulphonates (ABS) can be differentiated from each other.

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Massenspektren von Alkylbenzolsulfonaten durch Elektronenstoß-Massenspektrometrie mit Probenerhitzung im Elektronenstrahl

Zusammenfassung Mit Hilfe der vorgeschlagenen Technik ergeben Natriumbenzolsulfonate einen starken Dinatriumsulfonatpeak sowie Clusterionen von Tri- und Tetranatriumsulfonaten. Natriumdodecylbenzolsulfonate ergeben ebenfalls Molekular- und Natriumionenpeaks und klare Fragmentierungsmuster, die denen der entsprechenden Kohlenwasserstoffe vergleichbar sind. Nach den erhaltenen Resultaten können »harte« und »weiche« Alkylbenzolsulfonate voneinander unterschieden werden.

     

Nondestructive Analysis of Metals by PGAA at the Budapest Research Reactor

Since 1996 several applications of prompt gamma activation analysis have been performed at the new Budapest PGAA facility. This paper deals with the investigation of metal objects. We report the results of nondestructive detection of H in amorphous metals, multielement analysis of Roman bronze brooches and measurement of silver concentration in Hungarian coins.     

熔融制样-X射线荧光光谱法分析铝合金

提出了用X射线荧光光谱法测定铝合金中镁、硅、钛、锰、铁、镍、铜、锌、铅等9种元素。样品0.2000g置于聚四氟乙烯杯中用200g·L~(-1)氢氧化钠溶液5mL溶解后,加硝酸10mL酸化,将溶液移入已盛有4.000g熔剂(四硼酸锂、偏硼酸锂与氟化锂以4.5比1比0.4的质量比混合)的铂金坩埚中,低温蒸干,并加热熔融制成厚度为2.5mm的玻璃状熔片,供X射线荧光光谱法分析用。该方法可适用于不同牌号、不同铸造或锻造热处理状态的铝合金样品分析。按该方法分析了4个标准样品,其测定结果与标准值相吻合。用一个铝合金标准物质(牌号ZLD 108)制备10个样片并测量,各元素相对标准偏差在0.62%～2.7%之间。     

选矿流程样品中铌和钍的X射线荧光光谱法测定

采用Ｘ射线荧光光谱法，以铑靶的康普顿散射线强度为内标，测定了铁矿石选矿流程样品中的铌和钍。方法简便、快速、准确，完全能够满足选矿工艺研究和日常生产对样品中铌和钍分析的要求。     

Some Basic Studies on Non-Destructive Elemental Analysis of Bulky Samples by PGAA

An internal monostandard method for PGAA is proposed for completely non-destructive analysis of elements in bulky samples by the use of a neutron beam guided out from the reactor. The method is essentially the same as the k ₀ method except that it corrects for the change of relative -ray counting efficiencies caused by the absorption and scattering of neutrons and absorption of -rays within the sample. Some examples of applications to archaeological samples of earthen wares, bronze mirrors, and to voluminous meteorite samples are demonstrated, and its future application to the in-situ studies of distribution and metabolism of a certain elements in animals is also explained.     

Analysis of archaeological samples by the internal monostandard method of PGAA

Nondestructive determination of major and trace elements within voluminous materials has been demonstrated by prompt γ-ray neutron activation analysis. Some fragmented pieces of pottery bowls considered to have been produced in the late 18th century were analyzed by a new internal monostandard method, and noticeable differences of the elemental contents and significant correlations of the elemental distributions were observed among the samples. The possibility of identification of producing areas of unearthened material is demonstrated by the analytical results and the applicability of this method to the investigation of precious samples in a completely nondestructive way is verified in practice.     

X荧光玻璃熔片法分析铁矿石

使用无水四硼酸锂作为溶剂，在1050℃熔融制样，以X荧光光谱法测定铁矿石中铁、硅、铝、钙、镁、锰、钛、磷、硫等元素，其分析结果的精密度和准确度可与化学法相比。     

PGAA metals analysis in tailings in Zaida abandoned mine,high Moulouya,Morocco

The basin of Moulouya Oued is a region where mining industry has been developed early in the 20th century. As a consequence, residues generated from past mining activities over the years have been dumped as piles of tailings. Zaïda is one of the most affected region in this basin because of lead mine exploitation for long time. The aim of this study is to determine the amount of trace elements and the contamination of the river sediments. Analysis of collected samples has been achieved using the prompt gamma activation analysis method. The samples, in form of powders, were enclosed in Teflon sheets. The spectra were analyzed using HYPERMET PC software and the chemical composition is calculated using an Excel-macro that provides the concentrations as molar and weight percentages, as well as the corresponding masses of the oxides. The validation of the analytical method is demonstrated with the analysis of a reference material. The results show that the distribution of the studied metals (Pb, Zn, Cu, Cd, Cr Ni, and As) in the basin is dependent on location with a very significant contamination by Pb, Zn, Cu, Cd, Cr, and Ni close to the lead mine sites.     

Complementarity of XRFS and LIBS for corrosion studies

A study of ancient coins with different corrosion degrees and the same or different composition has been carried out by using energy-dispersive X-ray fluorescence spectrometry (XRFS) and laser-induced break-down spectroscopy (LIBS). The results obtained show the complementarity of both techniques: XRFS provides information about the superficial composition which is used for the assignation of atomic lines in LIBS, and this provides in-depth and tomographic information. Thus, some very superficial impurities such as Ag, Cl, Au, Sr and Sb are only detected by XRFS, while highly corroded coins of iron-based alloy provided no iron signal by XRFS but increased concentration of this element up to constant composition by LIBS by increasing the shot number. The average of the same laser-shot number for all sampling positions of a sampling zone produces a significant improvement of the signal-to-noise ratio (SNR) in the detriment of punctual information as that obtained by single-position kinetic series.     

Comparative PGAA and NAA results of geological samples and standards

Concentrations of major and trace elements in volcanic rock and soil samples, including geological standard reference materials, were determined by neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA), both using the k ₀-standardization method. The paper highlights the different experimental procedures, such as sample preparation, data collection and spectrum evaluation. In geological samples, PGAA gives precise results for major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and—as a unique method—for H), for some of the light trace elements as B and Cl, as well as for Sc, S, Cr, Co, Ni, Cd, Nd, Sm and Gd. NAA is sensitive for the rare earth elements, and for many major (Ti, Al, Fe, Mn, Mg, Ca, Na, K) and trace elements (e.g.: Sc, V, Cr, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, As, Sb, Ce, Ba, Hf, Ta, W). For most major elements the results obtained by the two methods show good agreement. The comparison of the results obtained for trace elements is not always possible, since PGAA is less sensitive and concentrations are often below its detection limits. Nevertheless, the complementarity of NAA and PGAA allows nearly panoramic analysis of geological materials.     

Rapid analysis of aldehydes by simultaneous microextraction and derivatization followed by GC-MS

Ultrasound-assisted dispersive liquid-liquid microextraction (UDLLME) and simultaneous derivatization followed by GC-MS was developed for the analysis of four aldehydes including acetaldehyde (ACE), propionaldehyde (PRO), butyraldehyde (BUT) and valeraldehyde (VAL) in water samples. In the proposed method, the aldehydes were derivatized with O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine (PFBHA) and extracted by UDLLME in aqueous solution simultaneously; finally, the derivatives were analyzed by GC-MS. The experimental parameters were investigated and the method validations were studied. The optimal conditions were: aqueous sample of 5 mL, PFBHA of 50 μL, 1.0 mL ethanol (disperser solvent) containing 20 μL chlorobenzene (extraction solvent), ultrasound time of 2 min and centrifuging time of 3 min at 6000 rpm. The proposed method provided satisfactory precision (RSD 1.8-10.2%), wide linear range (0.8-160 μg/L), good linearity (R(2) 0.9983-0.9993), good relative recovery (85-105%) and low limit of detection (0.16-0.23 μg/L). The proposed method was successfully applied for the analysis of aldehydes in water samples. The experimental results showed that the proposed method was a very simple, rapid, low-cost, sensitive and efficient analytical method for the determination of trace amount of aldehydes in water samples.     

A new gamma-ray spectrum catalog and library for PGAA

New measurements have been performed at the PGAA facility at the Budapest Research Reactor (BRR) in order to create a prompt -ray catalog for qualitative and quantitative analysis. The measured spectra were accurately analyzed by HYPERMET-PC. Prompt -ray energies and associated -ray production cross-sections have been determined by internal standardization. The resulting catalog contains prompt -ray data from neutron capture and other reactions such as (n,), and decay -ray data from short-lived reaction products. Data have been measured for nearly all stable elements, from hydrogen to uranium. Generally, data for several isotopes are given, to enable isotopic analysis as well. The whole library, including elemental spectra, will be available as a book.     

Optimization of XRFS for the analysis of toxic elements and heavy metals in coffee products

XRFS can be successfully used for routine on-line analysis of different agricultural products, for instance where food quality control is necessary. The optimization of the system for such purposes and the results obtained are shown on the example of the analysis of coffee.     

X射线荧光光谱法测定聚合物材料中铅和镉

提出了X射线荧光光谱法测定聚合物材料中铅和镉的方法。将粒径小于4mm的样品颗粒置于样品杯中,保持样品厚度大于16mm,加盖后按仪器工作条件进行测定。铅和镉的线性范围依次在1 033μg.g-1和980μg.g-1以内,检出限依次为0.31μg.g-1和0.69μg.g-1。方法用于分析标准物质(ERM-EC680k和ERM-EC681k),测定值与认定值相符。     

X射线荧光光谱法同时测定煤焦灰分中主次组分

采用玻璃熔融法制样,选用标准样品及其与其他标准样品的混合物制作工作曲线,并以经验α系数校正元素重叠干扰和基体效应,用X射线荧光光谱法对煤焦灰分中的二氧化硅、氧化钙、氧化镁、氧化铝、氧化锰、二氧化钛和氧化亚铁等7种主次组分进行测定。该法分析结果与化学法测定值相符;对同一样品测定6次,各组分测定值的相对标准偏差在0.11%～5.8%之间。