Accurate determination of sulphur in steels and certain heat-resisting alloys by isotope dilution mass spectrometry

A mass spectrometric isotope dilution method for the determination of sulphur in steels and certain alloys has been investigated. Addition of bromine in the dissolution of carbon steels was necessary for the complete conversion of sulphur into sulphate. The relative standard deviation was better than 1.5% for sulphur contents in the range 40-3,000 ppm. The results on standard materials were in good agreement with the certified values for samples of BCS, but lower than those for JSS and NBS.     

Certification of the sulphur content of three rapeseed reference materials

Summary The sulphur content of three rapeseed reference materials has been certified on the basis of measurements made by inductively coupled plasma-optical emission spectroscopy, isotope-dilution mass spectrometry and ion chromatography. Their suitability for the calibration of x-ray fluorescence spectrometers used for measuring sulphur in rapeseed samples was established.     

A complete dissolution procedure for SnPb solders using nitric and hydrochloric acids with simultaneous determination of major and trace elements by ICP/OES

A complete and fast dissolution procedure for tin and lead based solders is described. Trace and major elemental concentrations are determined by inductively coupled argon plasma emission (ICP) spectroscopy. One gram solder samples in the concentration range of 40-63 wt % tin are completely dissolved using nitric and hydrochloric acids. ICP analyses of certified reference materials prepared by this dissolution method are reported and compared to reference values. Based on comparison, the sample preparation method discussed is successful for quantitative analysis of trace and major elements in tin-lead solders.     

Time resolved sulphur and nutrient distribution in Norway spruce drill cores using ICP-OES

Methods were developed for detailed dendrochemical studies of low sulphur contents in Norway spruce (Picea abies L. Karst.). This tree species is the dominant conifer species in Northern and Central Europe and therefore predestined for a possible use as an environmental archive. Two independent digestion procedures were investigated with respect to their suitability for element determination and optimised for analysis of the low sulphur content in wood. A modified oxygen bomb combustion procedure and a microwave acid digestion procedure were evaluated with the goal to obtain sufficient detection limits in order to access low concentrated non-metals with an appropriate time resolution. Method development included evaluation of strategies preventing losses of volatile sulphur species. Digestion efficiency was demonstrated by recovery rates for various certified plant standard reference materials (NIST 1572, NIST 1547, RM 8436, BCR 101, NIST 1515, RM 8436, NIST 1573, NIST 1575) as well as self prepared standards with defined low sulphur content of 20 to 200 mg kg^?1, which are typical for Norway spruce wood samples. Ultra sonic nebulisation (USN) was evaluated with respect to signal enhancement for sample introduction to inductively coupled plasma optical emission spectrometry (ICP-OES). The optimised procedure was applied to Norway spruce drill cores from locations with different environmental conditions in Switzerland, in order to investigate the anthropogenic impact of sulphur and the suitability of Norway spruce as an environmental archive for sulphur.     

Establishing a basis for nuclear archaeometry in Australia using the 20 MW OPAL research reactor

The k ₀-method of standardisation for instrumental neutron activation analysis (INAA) has been used at the OPAL research reactor to determine the elemental composition of three certified reference materials: coal fly ash (SRM 1633b), brick clay (SRM 679) and Montana soil (SRM 2711). Of the 41 certified elements in the three materials, 88 percent were within five percent of the certified values and all determinations were within 15 percent of the certified values. The average difference between the measured and certified values was 0.1 percent, with a standard deviation of 4.1 percent. Since these reference materials are widely used as standards in the analysis of archaeological ceramics by INAA, it has been concluded that the INAA facility in Australia is particularly well-suited for nuclear archaeometry.     

Determination of iron,cobalt, nickel,manganese, zinc,copper, cadmium and lead in human hair by inductively coupled plasma-atomic emission spectrometry

A method was standardized for the dissolution of hair samples and analysis was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES). Hair samples were brought into solution by using a mixture of nitric acid and hydrogen peroxide. Various parameters that influence the sample preparation, namely temperature, digestion time and ratio of acid mixture were studied and standardized. The optimized method has been employed to digest standard reference materials and hair samples of residents of India, collected from different age groups and sex, and analyzed for Fe, Co, Ni, Mn, Zn, Cu, Cd and Pb. The values agree for most of the metals with the data reported for human hair samples of residents of India. The NIES CRM Human Hair No. 5 and IAEA Reference Hair HH-1 certified reference materials were used in order to verify the accuracy of the method and the results were in excellent agreement with the certified values.     

Recent developments in NIST botanical SRMs

The National Institute of Standards and Technology (NIST) (formerly the National Bureau of Standards (NBS)) issued the first botanical reference material certified for elemental content in January 1971, as Standard Reference Material (SRM) 1571, Orchard Leaves. In the following years a total of nine additional botanical certified reference materials have been issued by NIST. Each of these materials was certified for major, minor and trace elements except for SRM 2695, certified for fluorine only. Botanical SRMs issued since 1991 are significantly improved over previous materials in a number of ways. Probably the most significant change is the use of a jet-milling process to grind them to extremely fine particles. This has resulted in botanical SRMs with significantly improved homogeneity. These NIST reference materials are described with information on homogeneity, drying techniques and grit content.     

Dissolution kinetics of copper(II) oxide in water saturated by sulphur dioxide

The dissolution and the kinetics of dissolution of cooper(II) oxide in water saturated by sulphur dioxide has been studied. In the experiments, the particle size, the flow rate of the gas, the solid to liquid ratio, and the reaction temperature have been chosen as parameters, while the stirring rate was held constant. As a result of present experiments, it was observed that the decrease of the particle size, the solid to liquid ratio, and an increase of the reaction temperature increased the dissolution rate. It was also observed that the flow rate of sulphur dioxide in the range of its flow rate values did not affect the dissolution rate. The reaction kinetics of copper(II) oxide according to the heterogeneous reaction models was examined and it was found that the dissolution rate was controlled by chemical reaction. The calculated activation energy is 66.50 kJmol^?1. © 1994 John Wiley & Sons, Inc.     

电感耦合等离子体质谱法对GSS系列土壤及沉积物标准物质中多种元素的定值

介绍对10种GSS系列土壤及沉积物标准物质中多种元素进行定值的方法和结果，采用模拟土壤元素天然组成比值的校正溶液，对元素间的基体干扰具有明显的抑制作用，利用115In-103Rh双内标元素校正系统，可有效地抑制分析信号的动态漂移，建立了电感耦合等离子体质谱法对土壤及沉积物标准的物质中多种元素定值的方法，用该方法对GSS－4，GSS－5，GSS－8及GSD－9共4种土壤标准物质进行测定，绝大部分元素的测定结果与标准值的相对误差小于10％，相对标准偏差小于10％，对GSS－10－GSS－16，AMS－1，BEM及DMS－1共10种土壤及沉积物待定值标准物质进行定值，绝大部分元素测定结果的相对标准偏差小于10％。     

X射线荧光光谱法测定地质样品中的硫和氟

采用粉末压片制样-X射线荧光光谱法研究地质样品中硫(S)和氟(F)元素的快速测定方法。通过分级过筛实验优化确定样品粒度,探讨样品粒度对测定结果的影响,并进行实际样品和标准物质验证。结果显示,样品粒度为85μm时,经实际样品和标准物质验证,测定结果与化学值和标准认定值相符,且相对标准偏差(RSD)均小于2%。方法具有准确度高、检出限好、测试范围宽、简便快速等优点,能确保样品分析结果的准确性,实现了地质样品中S和F的快速测定。     

Elimination of major molecular chlorine interference in the iodimetric determination of sulphur in saline sediments

Free chlorine evolved during the high-frequency induction furnace combustion of saline sediments at >1500°C interfered very seriously in the iodimetric titration of liberated sulphur dioxide. Remedies based on absorption of chlorine on copper, antimony and other traps were only partly successful; copper was the most efficient but the loss of titratable sulphur was still very large. Sample desalination with refluxing anhydrous methanol in a Soxhlet extractor was the only method found to give satisfactory performance. This procedure was successful for a broad range of salinity values (reference sample mixed with sodium chloride in ratios of 0.09–1.6) without affecting the sulphur minerals present. The procedure showed excellent precision and good agreement with the “best” values available for the USGS MAG-1 Marine Mud (0.40% S) with a relative standard deviation of 1.29%. Iodimetric determination of sulphur in salt core samples (with the sediment in minor proportions) would also be possible.     

中国海大陆架沉积物超细标准物质系列研制

5个中国海大陆架沉积物标准物质的原样分别取自东海和南海,样品风干后,先经球磨制备成200目的均匀粉体,再用气流磨进一步加工成超细粒度的均匀样品.采用激光粒度仪检测了样品的粒度分布,5个样品的平均粒度均小于4 μm(约800目).采用高精度的XRF检验了样品的均匀性并以高灵敏度的ICP-AES、ICP-MS相配合确定了其最小取样量(5 mg).有12个实验室参加了合作定值研究,定值组分均为60个,其中MSCS-1,2分别有50和51个组分定为标准值,MSCS-3,4,5有52个组分定为标准值.全组分百分总和分别为99.9%, 99.9%, 100.4%, 100.1%和99.7%.     

Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the ?ν = 0 vibrational sequence within the electronic transition X¹∑⁺ → A¹П, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd_xS_y molecules. At the 258.056 nm line, with the wavelength range covering central pixel ± 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg⁻¹ in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg⁻¹ in flame molecular absorption spectrometry.The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with sulphur content determined by X-ray fluorescence spectrometry).     

Efficiency of decomposition procedures for the determination of some elements in soils by atomic spectroscopic methods

Nine decomposition procedures for soil samples, such as via acid mixtures and fusion in open systems and microwave and autoclave dissolution (in closed systems under elevated temperature and pressure) were assessed using certified soil reference materials. The determination of various elements in solutions was performed by FAAS and ICP-OES and the results were compared with certified values and with direct current arc OES analysis.     

Microwave dissolution for the determination of mercury in biological samples

Microwave dissolution in closed teflon vessels is described for the determination of ng g^?1 contents of mercury in biological materials, prior to two-stage gold amalgamation and cold-vapour atomic absorption spectrometry. Six samples can be decomposed simultaneously within 20 min, with a preset heating programme. The detection limit is 0.84 ng g^?1 for a 100-mg sample. Results for six certified reference materials agreed with the certified values.     

Comparison of the acid combinations in microwave-assisted digestion of marine sediments for heavy metal analyses.

Sediments as a tool for monitoring contamination by heavy metals in the environment has long been considered. It is therefore a necessity to produce reliable data for such purposes. Microwave-assisted acid dissolution has proved to be a suitable method for digesting complex matrices, such as sediments. However, due to the infancy of the technique, the procedures are numerous and varied in both the reagents used and microwave conditions. In this study, the efficiency of two recommended acid mixtures, a HNO3-HF mixture and an aqua regia-HF mixture, under the same microwave digestion conditions were compared using certified reference materials. It was observed that the HNO3-HF mixture showed better efficiency than the aqua regia-HF mixture in most of the heavy metals analyzed in all certified reference materials used.     

Efficiency of decomposition procedures for the determination of some elements in soils by atomic spectroscopic methods

Nine decomposition procedures for soil samples, such as via acid mixtures and fusion in open systems and microwave and autoclave dissolution (in closed systems under elevated temperature and pressure) were assessed using certified soil reference materials. The determination of various elements in solutions was performed by FAAS and ICP-OES and the results were compared with certified values and with direct current arc OES analysis. Received: 3 March 1997 / Revised: 30 May 1997 / Accepted: 3 June 1997     

The stability of the certified reference ores MP-1 KC-1 and SU-1 towards air oxidation

The stability of three certified reference sulphide ores, MP-1, KC-1 and SU-1, towards air oxidation has been measured at 50 degrees and 40, 62 and 82% relative humidity, and at 62% relative humidity and 34 degrees and 67 degrees . Both the relative humidity and temperature affect the rate of oxidation but their relative importance depends on the mineralogical composition of the ore. Changes in the water-extractable metals and elemental sulphur content on oxidation have been determined. It is concluded that these ores may be stored safely in sealed bottles under normal laboratory conditions.     

Simultaneous determination of boron,phosphorus and sulphur in some biological and soil materials by inductively-coupled plasma emission spectrometry

Atomic emission lines at 249.678 nm, 214.911 nm and 180.735 nm are used simultaneously to determine total concentrations of boron, phosphorus and sulphur respectively, in plant and soil sample digests by means of inductively-coupled plasma emission spectrometry. The digestion procedures chosen enable these elements to be determined simultaneously on a single digest. Analytical data are compared after using various digestion procedures on standard reference materials. Actual and potential interelement interferences in the plasma are discussed together with attempts to overcome these interferences. Limitations for simultaneous determinations of boron, phosphorus and sulphur remain in the digestion and dissolution procedures.     

Automated determination of sulphur in organic compounds

The paper reviews methods of sulphur determination over the last 120 years. Classical methods are presented in a historical view, and the present state of automatic procedures of sulphur estimation is discussed. 104 key references concerning sulphur analysis are cited. On the basis of the present level of the development of elemental analysis, a prognosis of directions of the development of sulphur microanalysis is attempted.