Determination of Total Carbon and Sulfur in Fifty-two Geochemical Reference Samples by Combustion and Infrared Absorption Spectrometry

The contents of total carbon and sulfur in 52 international geochemical reference samples have been determined by a method of infrared absorption following combustion in a high-frequency induction furnace. A comparison with published data shows clearly the need for much more data on most samples before consensus values could be assigned.
Les teneurs en carbone et soufre totaux ont été déterminées dans 52 échantillons géochimiques de référence par combustion suivie de spectrométrie d'absorption infra-rouge. Une comparaison de ces résultats avec ceux de la littérature montre bien la nécessité de disposer davantage de données pour pouvoir fixer des valeurs de consensus.     

Determination of Beryllium and Zirconium In 45 Geochemical Reference Samples By Inductively Coupled Plasma Emission Spectrometry

The beryllium and zirconium contents of 45 geochemical reference samples have been determined by inductively coupled plasma after fusion of the samples with lithium metaborate and dissolution of the melt in dilute nitric acid. The method described here is rapid and sample preparation straightforward. Good agreement is shown with previously published results for these two elements. A correction has to be made for an interference due to vanadium in determining the beryllium content, and there is a slight interference due to yttrium in the determination of zirconium. The detection limit for beryllium is about 0.2 μg g^-1 and for zirconium about 15 μg g^-1 in the sample.     

Determination of Fluorine and Total Water in Thirty-Three International Geochemical Reference Samples

Thirty-three reference samples from the United States Geological Survey (USGS), Centre de Recherches Pétrographiques et Géochimiques (CRPG, France), Association Rationale de la Recherche Technique (ANRT, France), National Institute for Metallurgy (NIM, South Africa), Geotechnic Institute (GI, Austria), Mineralogical Institute of Basel and Bern (Switzerland), Zentrales Geolo-gisahes Institut (ZG1, DDR) and from the For-chungeinstitut der Zementinduatrie (Düsseldorf, GDF) were analysed for their fluorine and total water content. Fluorine was determined, after pyrohydrolysis, with an ion-selective electrode. Total water was determined, after pyrolysis, by Karl-Fischer titration. Our values, five determinations on each sample, are compared with the preferred values.     

Determination of Silver in Seventy-Three Geochemical Reference Samples by Atomic Absorption Spectrometry

The silver content of seventy-three geochemical reference samples has been determined by atomic absorption spectrometry using an air-acetylene flame or a graphite furnace atomizer, after extraction of silver as iodide with methyl isobutyl ketone (MIBK). A comparison with published data shows clearly the need for much more data on most reference samples.     

Determination of Thallium in Eighty-Seven Geochemical Reference Samples by Atomic Absorption Spectrometry

The thallium content of eighty-seven geochemical reference samples has been determined by atomic absorption spectrometry using an air-acetylene flame or a graphite furnace atomizer, after extraction of thallium as chloride with methylisobutylketone (MIBK). A comparison with published data show clearly the need for much more data on most reference samples.     

Determination of Selenium in Geochemical Reference Samples Using Flameless Atomic Absorption Spectrometry

Sixteen international and six inter-laboratory geochemical reference samples have been analysed for their selenium content. No previous Sedata are available for thirteen of them. Selenium has been separated from silicate matrix by volatilization and was determined with flameless atomic absorption spectrometry. An outline of the procedure is given. The limit of detection is 10 ng Se per 1 g of sample. Time required for one full analysis is 1.2 to 2.5 hours depending on amount of sample to be volatilized.     

Determination of Bismuth in Eighty-Three Geochemical Reference Samples by Atomic Absorption Spectrometry

The bismuth content of eighty-three geochemical reference samples has been determined by atomic absorption spectrometry using either a hydride generation and heated quartz cell atomizer or a solvent extraction and carbon tube atomizer. The agreement between the present results and published data is generally good.     

Determination of Gold in Sixty Geochemical Reference Samples by Flameless Atomic Absorption Spectrometry

The gold content of sixty geochemical reference samples has been determined by atomic absorption spectrometry using a graphite furnace atomizer after digestion of sample with aqua regia and extraction of gold as chloride by methylisobutylketone. A comparison with published data shows clearly the need for much more data on most samples before consensus values could be assigned.
La teneur en or dans soixante échantillons géochimiques de référence a été déterminée par le spectromètre d'absorption atomique équipé d'un four à graphite. L'échantillon a été mis en solution avec de l'eau régale et l'or extrait avec du methylisobutylketone. Un examen des données publiées sur l'or montre qu'il faut davantage de résultats pour fixer des valeurs de consensus dans la plupart des échantillons.     

Determination of Gold in Twenty Geochemical Reference Samples by Flameless Atomic Absorption Spectrometry

After acid digestion, gold is extracted with MIBK and determinated by flameless atomic absorption spectrometry. The results for six USGS reference samples and fourteen French geochemical standards are presented and discussed. The agreement with working values for these standards is in the range of pm 5%.     

Determination of Cesium in Sixty - Three Geochemical Reference Samples by Flame Emission Spectrometry

The cesium contents of 63 geochemical reference samples have been determined by flame emission spectrometry using an air-acetylene flame. The agreement between the present results and published data is generally good.     

Determination of Carbonate Carbon in 41 International Geochemical Reference Samples by Coulometric Method

The carbonate-carbon (CO₂) content of forty-one geochemical reference samples has been determined by coulometric method following acid treatment of the sample for releasing CO₂. The method is superior to the conventional methods in speed, accuracy, sensitivity, specificity, and the coverage of CO₂ range. The results on NBS limestone samples agree well with the certified values. The precision of the method is 0.5 % r.s.d., and the practical detection limit is 10 ppm C.     

Determination of Platinum and Palladium in Sixty-Eight Geochemical Reference Samples by Flameless Atomic Absorption Spectrometry

Platinum and palladium contents of sixty-eight geochemical reference samples have been determined by graphite furnace atomic absorption spectrometry after digestion of sample with aqua regia and hydrofluoric acid and extraction of platinum and palladium as iodides by methylisobutylketone (MIBK). The data are compared with those from other studies and crustal abundances.     

Determination of Trace Amounts of Tin in Seventy-Three Geochemical Reference Samples by Atomic Absorption Spectrometry

The tin contents of 73 geochemical reference samples have been determined by atomic absorption spectrometry using an argon-hydrogen flame after extraction of tin (IV) as iodide with benzene. The agreement between the present results and published data is generally good.     

酸溶-电感耦合等离子体发射光谱法和燃烧-红外吸收法测定不同类型地球化学样品中的硫

测试地质样品中的硫含量,以电感耦合等离子体发射光谱法(ICP-OES)和燃烧-红外吸收光谱法应用最为广泛。ICP-OES法灵敏度高、稳定性好,但受样品预处理和基体干扰的影响较大;燃烧-红外吸收光谱法便捷高效,但受结晶水红外吸收干扰,分析硫含量低的样品稳定性较差。本文采用5种酸溶方式处理样品ICP-OES测定硫含量,同时采用燃烧-红外吸收光谱法测定低中高含量的硫,综合比较了两类方法的检出限、检测范围、精密度和准确度、分析效率等,明确了各方法的适用范围。实验中确定了燃烧-红外吸收光谱法最佳测试条件为：称样量0.0500g,燃烧时间25s,分析时间40s,氧气流量4.0L/min;通过标准物质验证,该方法检出限为10×10-6,检测范围为10×10-6~470000×10-6,相对标准偏差(RSD) < 6%(n=12),相对误差绝对值小于8%。实验结果表明,ICP-OES分析效率高,但是样品处理时间长,检测范围不如燃烧-红外吸收光谱法宽;燃烧-红外吸收光谱法采用固体直接进样,成本低,用高氯酸镁作为干燥剂可解决结晶水红外吸收干扰问题。总体上,ICP-OES法适用于分析硫含量低的样品或作为测试结果佐证的手段,可实现多元素联测;批量样品或基体类型复杂的样品宜采用燃烧-红外吸收光谱法测试,更加便捷。     

红外碳硫仪测定矿石中高含量硫的探讨

探讨了用红外碳硫测定仪测定矿石中高含量硫需注意的一些影响因素,包括标样的选择、减少天平误差、称样量、样品的充分燃烧以及仪器的稳定性,说明了用红外碳硫仪测定矿石中高含量硫的可行性。     

发射光谱法测定化探样品中金

以盐酸、氯化钠、高锰酸钾为溶金液,炭粉为缓冲剂,铂为内标,电弧发射光谱法测定化探样品中的金。方法对金的测定范围为0.3~1500 ng/g,检出限为0.22 ng/g,精密度(RSD,n=12)为3.2%~12.8%。方法经国家一级标准物质验证,测定结果与标准值相符。     

Spectrophotometric Determination of Molybdenum and Tungsten in Forty Geochemical Reference Samples

The molybdenum and tungsten contents of 40 geochemical reference samples have been determined by a spectrophotometric procedure. The agreement between the present results and published data is generally good.     

荧光光度法测定化探标样中的铪

锆和铪的化学性质非常相似,要用简便方法分离这两个元素是困难的,用化学方法测定微量锆和铪也是困难的。Kouimtzis和Brookes曾经在这方面做了一些工作,在他们工作的基础上,我们确立了实验条件并应用于化探标些中锆、铪的测定。     

Determination of Total Sulfur in Fifteen Geological Materials Using Inductively Coupled Plasma‐Optical Emission Spectrometry (ICP‐OES) and Combustion/Infrared Spectrometry

A method for the determination of total sulfur in geological materials by inductively coupled plasma‐optical emission spectrometry (ICP‐OES) is described. We show that good results were obtained using this method even for sample types with very low (< 20 μg g^?1) sulfur concentration (e.g., peridotite). Sulfur was determined in fifteen geological reference materials with different sulfur contents. For reference materials with certified sulfur contents, the ICP‐OES method gave results in excellent agreement with certified values, and uncertainties better than 4% RSD. ICP‐OES results for sulfur in other reference materials yielded RSDs better than 10%, where S concentrations were > 100 μg g^?1 (except for diabase W‐2a, 16% RSD). Reference materials with lower sulfur contents (< 40 μg g^?1) showed much higher RSDs (17–18%). Except for RMs with certified values for sulfur, most data obtained by the combustion infrared detection method generally showed higher concentrations than those measured by ICP‐OES and a better RSD (≤ 8% for all materials except DTS‐2b).     

Total Sulfur Concentration in Geological Reference Materials by Elemental Infrared Analyser

Total sulfur is an analyte for which there are few determinations published, despite the fact that it is a very important element (e.g., a major element in most ores, an important gas constituent in global warming, an active participant in acid drainage). Most geological reference materials have very poor quality sulfur results, that is with relative standard deviations (RSD) in the range of 30–50%, even for concentrations over 100 μg g⁻¹ S, which compromises their use as calibrators. In order to provide modern results with low RSD, sulfur was determined in twenty-nine geological reference materials with a state-of-the-art elemental S/C analyser using metal chips (certified reference materials with a traceability link) and analytical grade sulfur for high concentration samples. Analytical parameters (sample mass, crucible degassing, calibration strategy, etc.) were optimised by testing. Our results agreed with reference material values provided by issuing bodies. Results for CCRMP SY-2 (129 ± 13 μg g⁻¹ S), which has been proposed as a sulfur reference material, were in agreement with the proposed modern value of 122 ± 3.7 μg g⁻¹ S.