PMBP-苯溶剂萃取-ICP-AES快速测定化探样品中15种稀土元素和钍

实验在pH=5.5的酸度下,使用PMBP-苯溶剂定量萃取化探样品中15种稀土元素和钍,然后用甲酸-8-羟基喹啉溶液反萃取稀土元素并在萃取后的有机相中再用50%盐酸反萃取钍,分离后ICP-AES同时测定的新方法。成功解决了盐酸、硝酸、氢氟酸、高氯酸消解后ICP-AES直接测定稀土元素基体成分复杂,质谱干扰严重,方法检出限高等问题,试样用过氧化钠-氢氧化钾熔融后,水提取,过滤,滤渣酸溶,经过沉淀和溶剂萃取等分离富集,对稀土组份进行全分析。其检出限为0.003μg/ml~0.068μg/ml,相对标准偏差(RSD)0.6%~2.0%,准确度及精密度符合国家及行业规范要求。采用建立的方法测定稀土铌钽矿中的稀土元素及钍,结果满意且具有实际应用价值。     

乙醇增敏-电感耦合等离子体发射光谱法测定矿石及选冶样品中的铌钽

电感耦合等离子体发射光谱法(ICP-AES)在铌钽测定方面获得广泛应用,但灵敏度较低、检出限较高,不能满足矿石和选冶样品中的低含量铌钽的检测要求。本文优化了ICP-AES测试过程中多种有机试剂的增敏效果,结果表明:样品采用氢氟酸-硝酸-硫酸敞开酸溶,选择乙醇作增敏剂,雾化效率最佳,当乙醇浓度为6%时,原子线Nb 292.781 nm、Ta 240.063 nm的灵敏度分别增强了180.5%和265.5%;铌的检出限由不加乙醇的5.85μg/g降低到3.22μg/g,钽的检出限由不加乙醇的10.65μg/g降低到5.03μg/g;Nb2O5回收率为97.7%~101.9%,Ta2O5回收率为96.8%~97.2%;方法精密度(RSD)6%。本方法适用于低含量和高含量铌钽的同时测定,尤其有利于选冶流程样品中同一批次的精矿、中矿和尾矿的同时测定,克服了以往分别采用光谱法和质谱法测定所产生的仪器间误差导致回收率吻合程度不好的缺陷。     

ICP-MS和ICP-AES测定地球化学勘查样品及稀土矿石中铌钽方法体系的建立

针对目前铌钽分析中出现的样品溶解不完全、元素易水解及现有分析技术流程复杂的情况,本文对常用的混合酸恒温电热板溶解和过氧化钠碱熔两种样品前处理方式进行优化,运用电感耦合等离子体质谱法(ICP-MS)、电感耦合等离子体发射光谱法(ICP-AES)两种技术手段,建立了测定地球化学勘查样品及稀土矿石中不同含量水平的铌、钽两套分析方法。对于铌、钽含量较低且易于分解的样品,采用硝酸-氢氟酸-硫酸混合酸恒温电热板消解ICP-MS方法测定;对于铌、钽含量高且难溶的样品,采用过氧化钠高温熔融ICP-AES方法测定。ICP-MS用于分析低含量样品更具优势,而高含量样品更适合运用ICP-AES。通过分析土壤、水系沉积物、岩石、稀有稀土矿石系列国家标准物质,结果表明混合酸处理ICP-MS分析方法的线性范围为0~200ng/mL;检出限为铌0.01μg/g,钽0.05μg/g;相对误差小于10%,精密度(RSD)小于6%;碱熔处理ICP-AES分析方法的线性范围为0~30μg/mL,检出限为铌0.2μg/g,钽2.5μg/g,相对误差小于10%,精密度(RSD)小于7%。这两套分析方法可以满足基体复杂、铌钽含量变化范围大、试样批量大的检测要求。     

四酸溶样电感耦合等离子体发射光谱法测定地质样品中的钪

分析地质样品中钪的含量,国家标准方法是采用过氧化钠熔融,过滤分离后电感耦合等离子体发射光谱法（ICP-AES）测定,过程繁琐,样品前处理引入大量盐类且分析结果精度不高,不能适应当前矿产勘查快速准确检测的需要。本文建立了采用硝酸、盐酸、高氯酸和氢氟酸处理样品,ICP-AES测定地质样品中钪的分析方法。选择5%盐酸为溶液介质,干扰元素含量低于2%时运用干扰因子校正法（IEC）优化谱线强度以及适量稀释溶液降低基体效应,提高了分析的准确度和精密度。方法测定范围宽（0.00003%~10%）;检出限为0.0016 μg/mL,优于国家标准方法检出限（0.004 μg/mL）;方法回收率为97.0%~99.3%,方法精密度（RSD,n=6）为0.4%~2.3%;国家一级标准物质的测定值和标准值吻合,分析结果准确可靠。虽然酸溶法不能完全溶解所有类型的地质样品,但对区域环境条件要求不高、简便快捷,本法以酸溶法替代碱熔法处理样品,避免了待测组分和干扰物质的引入,对ICP-AES测定钪的稳定性有较大改善,适用于批量快速分析地质样品中的钪元素。     

电感耦合等离子体发射光谱法测定铝土矿样品中镓三种前处理方法的比较

采用四酸(盐酸-硝酸-氢氟酸-高氯酸)溶矿、三酸(氢氟酸-硝酸-硫酸)溶矿及氢氧化钠碱熔法3种前处理方法对铝土矿样品进行分解,电感耦合等离子体发射光谱法(ICP-AES)测定样品中的镓。结果表明,四酸溶矿法的分解产物中存在较多的不溶物,镓与盐酸生成GaCl3导致挥损,镓的测定结果严重偏低;三酸溶矿法的分解产物中也存在较多的不溶物,导致测定结果严重偏低;氢氧化钠碱熔法处理铝土矿样品,酸化后所得溶液清澈透明,由于大量NaCl的存在,镓不会挥损,测定值准确度高。采用氢氧化钠碱熔,盐酸酸化提取,ICP-AES法测定镓的准确度高,精密度好,方法检出限为3.21μg/g,相对标准偏差(RSD,n=11)小于5%。经国家一级和二级标准物质分析验证,测定结果与标准值基本一致。     

电感耦合等离子体发射光谱法同时测定地质样品中的钍和氧化钾

同时测定地质样品中的钍和钾,可为放射性矿产资源勘探、天然放射性生态环境评价提供重要依据。对于钍,传统方法使用碱熔法分解试样分光光度法测定,此方法前处理冗长、复杂且不利于多元素的同时测定。而氧化钾一般采用酸溶法消解样品火焰原子吸收分光光度法测定,此方法测定浓度高的溶液需要稀释,检测效率较低。钍和氧化钾的分析涉及了两种配套方法。本文根据地质样品的化学成分特征,筛选出了用硝酸、氢氟酸和高氯酸为溶剂溶解样品,硝酸提取定容后,用电感耦合等离子体发射光谱法(ICP-OES)分别在波长401.913nm和766.490nm处,采用径向观测方式同时测定了钍、氧化钾的含量。钍、氧化钾的标准曲线相关系数均大于0.999,方法检出限分别为0.69μg/g、0.008%,标准物质的测定值与认定值基本一致,二者的对数误差绝对值小于0.1,相对标准偏差(RSD,n=6)小于6.0%,加标回收率在96.0%～104.0%之间,符合《地质矿产实验室测试质量管理规范》的要求。     

热水解-离子选择电极法测定海相碳酸盐岩中的氟

采用热水解法对样品进行预处理,离子选择电极法简易快速测定海相碳酸盐岩中氟元素的含量。方法检出限为25.1μg/g,精密度(RSD,n=11)为5.28%,回收率为96.5%~107.8%,结果令人满意。     

ICP-AES法在高品质硅石矿分析中的应用

传统的化学分析方法对高品质硅石矿(含量w≥96%)中的二氧化硅难以准确测定,使用电感耦合等离子体发射光谱法(ICP-AES)可对硅石中Al_2O_3等10种杂质元素进行准确测定,结合样品烧失减量,利用差减法即可准确计算出硅石矿中二氧化硅的精确含量。该方法检测范围在0.00002%~10%,检出限下线为0.0004μg/m L~0.051μg/m L,精密度为0.82%~4.39%,准确度高相对误差小于4.17%。     

电感耦合等离子体发射光谱法同时测定钒钛磁铁矿中铁钛钒

样品采用HCl-HF-HNO3-HClO4四酸溶矿、H2SO4-HF-HNO3三酸溶矿、KOH碱熔3种分解方法进行处理,电感耦合等离子体发射光谱法(ICP-AES)测定钒钛磁铁矿中的铁、钛、钒。结果表明,3种样品处理方法应用于ICP-AES测定是可行的。KOH碱熔适用于方法比对,三酸溶矿适用于样品内检分析,四酸溶矿适用于大批量样品测定。对铁、钛、钒三元素选择适合的分析谱线,以冶金行业钒钛磁铁矿标准样品制备的溶液绘制标准曲线,可消除试液基体和介质不一致对测定结果的影响。样品试液中主要共存离子对选择的分析线干扰小。采用四酸溶矿ICP-AES测定铁、钛、钒的方法检出限分别为0.0032%、0.0024%、0.0003%,方法精密度(RSD,n=12)为0.43%～5.06%。经实验室间比对和批量样品方法比对实验,测定值无明显系统偏差。建立的方法具有样品分解完全、测定含量范围宽、分析简便快速、结果准确等优点,适用于钒钛磁铁矿样品中铁、钛、钒的测定。     

敞开酸溶-电感耦合等离子体质谱法同时测定钨矿石和锡矿石中14种微量元素

钨矿石和锡矿石成分复杂,具有丰富的共生或伴生元素。在国家标准方法中,对其中的微量共生或伴生元素含量多采用单元素测定,分析强度大,效率低。本文采用混合酸在敞开体系中消解样品,以50%盐酸提取盐类,电感耦合等离子体质谱仪(ICP-MS)同时测定钨矿石和锡矿石中的锂钪铬钴镍铜铅锌铷钼铯锑铋钍等14种微量元素。通过比较碱熔法、盐酸+氢氟酸+硝酸+高氯酸四酸溶矿法、氢氟酸+硝酸+高氯酸三酸溶矿法这三种样品前处理方法,确定选择使用氢氟酸+硝酸+高氯酸三酸溶矿法溶解样品。ICPMS测定过程中,选择铑和铼作为内标元素,有效监控分析信号的漂移。测定结果表明,各元素的检出限为0.003~1.64μg/g,相对标准偏差在0.1%~3.1%,方法回收率在93.1%~104.3%。方法应用于实际钨矿石和锡矿石分析,测定结果与各元素标准测定值吻合较好。相对于传统处理方法,本法一次溶样,多元素同时测定,使分析效率得到了有效提高,更适合大批量多元素钨矿石和锡矿石样品的分析。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)