共查询到19条相似文献，搜索用时 125 毫秒
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分析地质样品中的溴碘,目前常用的提取方法有半熔法、稀氨水密封溶样法和热解法,但由于元素含量低、易损失,样品分解和溴碘的提取过程是主要的误差来源。本文改进了传统热解法的吸收装置,用液氮冷凝吸收代替常规的碱溶液吸收,提取地质样品中的溴碘,用电感耦合等离子体质谱法测定其含量。以标准偏差的10倍计算,稀释倍数为50,溴碘的检出限分别为0.06μg/g、0.01μg/g,低于传统热解法和半熔法,略高于稀氨水密封溶样法;精密度(RSD)为6.4%~21.0%。本方法相对于传统的碱溶液吸收热解法,减少了碱试剂的引入,降低了基体空白和稀释倍数,提高了精密度,操作较半熔法简便,可作为稀氨水密封溶样法的一种补充方法。因此,对于土壤和水系沉积物,宜采用稀氨水密封溶样法;对于岩石以及采用稀氨水密封溶样法难以完全提取的样品,可采用本方法。 相似文献
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作为土地环境质量的一项重要指标,石油类物质含量决定了土地的用途。对于复垦土地样品,在一定程度上反映了污染土地的复垦、治理效果。土壤样中的石油类物质测定方法主要有气相色谱法、红外分光光度法、紫外光谱法等。气相色谱法主要应用于测定样品中的饱和烷烃;红外分光光度法通过测定不同波数下的特征吸收值来表征样品中石油类物质,但采用四氯乙烯为溶剂,试剂环境危害大,前处理效率低,检出限高。本文针对复垦土地样品中石油类物质含量不高,组分多为难挥发且结构复杂、基质干扰大的特点,采用正己烷为溶剂、加速溶剂萃取(ASE)前处理,荧光分光光度计测定样品中的石油类物质。以海洋环境监测石油标准物质为标准样品配制工作曲线,线性相关系数r~2=0.9997;方法检出限为0.40mg/kg,检测下限为1.60mg/kg;实际样品方法精密度为1.10%～8.76%;基质加标回收率为89.0%～95.7%;检测实际样品的结果与现行有效的HJ 1051—2019红外分光光度法基本一致,高含量样品的测定结果高于红外法。本方法所用溶剂正己烷的毒性小于四氯乙烯,前处理方法ASE的自动化程度高,萃取效率高,精密度提高11.5%～67.3%。对于石油类组分结构相对复杂、难提取的样品,本方法检出限低于红外法(4mg/kg)。 相似文献
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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 总被引：1，自引：1，他引：0
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。 相似文献
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根据我国区域化探全国扫面工作要求,结合我国自己现有技术设备条件,实验研究了在同一份样品溶液中连续测定铜、铅、锌、镉、铁、锰、镍、钴八个元素的原子吸收分光光度测定法。本文介绍了测定上述八个元素的仪器最佳工作条件、共存元素干扰试验、样品分解方法、标准回收试验,并对美国地质调查所地球化学探矿参考样GXR-1～6的分析结果以及在本实验条件下测定这八个元素方法所能达到的灵敏度、精密度、准确度、工作效率方面的数据,拟定了操作步骤,为我国区域化探分析系统和质量监控系统的建立提供了基础实验资料和可供选择的方案。 相似文献
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钛矿资源主要类型为钛铁矿岩矿、钛铁矿砂矿、金红石矿。钛铁矿属于难熔矿物，一般不溶于硝酸、盐酸或王水。对于高品位钛铁矿，即使采用盐酸-硝酸-氢氟酸-高氯酸混合酸溶解样品，钛元素也易水解形成难溶的偏钛酸析出，常给分析带来很大困难。容量法和分光光度法等传统方法测定钛存在操作流程长、步骤多、效率低等不足。因此，选择合适前处理方法的同时将大型仪器分析方法结合起来，有利于提高钛铁矿分析的准确度和测试效率。本文建立了以2.0g过氧化钠为熔剂，使用刚玉坩埚在700℃熔融样品15min，热水浸取后盐酸酸化，用电感耦合等离子体发射光谱（ICP-OES）测定钛铁矿中的高含量钛元素的方法。实验中采用全程空白试液稀释定容标准溶液消除了钠基体影响，通过优化熔融温度和时间使样品分解完全，考察了过氧化钠用量来降低待测溶液中盐分以保证测定的稳定性，通过选择合适的分析谱线并采用背景扣除法消除光谱干扰。本方法检出限为0.0035%，测试范围为0.0066%～62.50%（均以TiO2含量计）；经钛铁矿国家标准物质（GBW07839、GBW07841）验证，相对标准偏差（RSD，n=12）为1.1%～2.1%，相对误差为-1.69%～1.11%。本方法应用于实际样品分析，相对标准偏差（RSD，n=12）均小于4%，TiO2分析结果与国家标准方法（硫酸铁铵容量法）一致。本方法有效解决了钛铁矿分解不完全及高含量的钛易水解的问题，实现ICP-OES对不同类型钛铁矿样品中钛元素的定量分析。 相似文献
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现有的国家标准及行业标准方法测定水中溴及碘均较繁琐、效率低，且结果是某一形态溴或碘含量，不同方法得到的结果存在差异，建立一个简单快速测定地下水中溴量及碘量的方法非常重要。在优化仪器参数下，建立了电感耦合等离子体质谱同时测定地下水样品中溴含量及碘含量的方法，研究了测定中钾对溴的干扰因素，并对比讨论了不同实验条件下的结果，以及pH对样品测定的影响。最终确定水介质的Re元素作内标，定量限均为1.01μg/L,精度为2.80%,用国家标准物质验证了该方法的准确度，测定实际地下水样品加标回收率均为85%～110%,可用于无有机污染的地下水等环境水质检测。 相似文献
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为分析金精矿中高含量Ag,加入浓HNO3处理样品中的S,采用王水溶样,使矿样分解完全并降低原子吸收测量时的背景干扰值。称取具代表性样品的最低重量,通过控制HCl介质的浓度,使溶液中的AgCl白色沉淀完全转化为[AgCl]2-配离子,在HCl介质中,用火焰原子吸收分光光度法直接测定Ag。选取2件不同含量的金精矿进行方法的精密度、准确度试验,分析结果表明,该方法的检出限为1×10-6,加标回收率99%～102%。 相似文献
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Hélène Balcone‐Boissard Agnès Michel Benoît Villemant 《Geostandards and Geoanalytical Research》2009,33(4):477-485
Concentrations of halogens (fluorine, chlorine, bromine and iodine) were determined in six geochemical reference materials (BHVO‐2, GS‐N, JG‐1, JR‐1, JB‐1b, JB‐2). Halogens were first extracted from powdered samples using a pyrohydrolysis technique, then hydrolysis solutions were analysed by ion chromatography for F and Cl and inductively coupled plasma‐mass spectrometry for Br and I. The detection limits in solutions were 100 μg l?1 for both F and Cl and 10 ng l?1 for Br and I. Considering the extraction procedure, performed on a maximum of 500 mg of sample and producing 100 ml of pyrohydrolysis solution, detection limits in rock samples were 20 mg kg?1 for F and Cl and 2 μg kg?1 for Br and I. The mean analytical errors on the studied composition ranges were estimated at 10 mg kg?1 for F and Cl, 100 μg kg?1 for Br and 25 μg kg?1 for I. The concentration values, based on repeated (generally > 10) sample analysis, were in good agreement generally with published values and narrowed the mean dispersion around mean values. Large dispersions are discussed in terms of samples heterogeneity and contaminations during sample preparation. Basaltic RMs were found to be more suitable for studies of halogen compositions than differentiated rock material, especially granites – the powders of which were heterogeneous in halogens at the 500 mg level. 相似文献
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新疆北部石炭纪岩相古地理 总被引：4，自引：0，他引：4
文章采用野外露头、钻井地质相结合的分析方法,讨论了新疆北部石炭纪的岩相古地理环境。野外露头、钻井资料的沉积建造、沉积相分布及古生物组合特征综合表明,新疆北部石炭纪古地理总体特征表现为由早石炭世的深海-半深海相、浅海相向晚石炭世的浅海相、海陆过渡相及陆相演化的趋势。岩石组合类型由早石炭世的活动陆缘型岛弧火山岩、深海复理石及海相碳酸盐岩向晚石炭世的裂谷型火山岩、陆相碎屑岩、海相碎屑岩及海相碳酸盐岩过渡。早、晚石炭世不同地区的古地理及其相应的岩石组合类型存在明显的差异。 相似文献
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浙江江山藕塘底组陆源碎屑与碳酸盐混合沉积特征及其构造意义 总被引：17，自引：3，他引：14
浙江江山藕塘底组是晚石炭世威宁期陆源碎屑与碳酸盐的混合沉积,包括两种组分在同一岩层内相互混杂形成混积岩和陆源碎屑岩与碳酸盐岩互层形成混积层系。藕塘底组是海陆交互环境的沉积产物,剖面结构具有下细上粗的岸进序列。混积岩形成于滨岸浅滩环境,由沿岸流和回流将河口或滨岸海滩的石英砂带到滨岸浅滩和潮坪相碳酸盐沉积区混杂而成。具两种混积层系类型,即浅海滨岸环境中砂岩与碳酸盐岩互层、河流相碎屑岩与海相碳酸盐岩互层。研究表明,混合沉积成因属“相混合”,主要受区域构造隆升、全球海平面上升和盆地水介质条件特性控制。区域海平面周期性变化和岸进序列可能是华夏古陆强烈隆起的结果。作者还讨论了混合沉积的分类和命名,将陆源碎屑与碳酸盐层相互交替构成的互层和夹层组合称为“混积层系”,并建议将“混积岩”一词用来表征两种组分相互混杂这种特殊沉积事件,而不用作具体岩石名称. 相似文献
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<正>The Outangdi Formation in Jiangshan,Zhejiang,is the mixing deposit of terrigenous clastics and carbonates in Weiningian of the late Carboniferous.The mixing deposits include interbeddings, which constitute a series of alternated clastic and carbonate beds and mixing within the same bed which forms"hunji rock".The Outangdi Formation has the features of intercalated marine and terrestrial deposits with the progradational sequences,which are lower fine and upper coarse sedimentary granularity in the section.Hunji rock is formed in a seashore environment.It is a mixed carbonate sediment found in beaches or tideland facies with quartz sand taken from a bayou or beach by coastwise flow and circumfluence.There are two kinds of hunji sequences:(1) interbeds of sandstone and carbonate rock in seashore environments;and(2) interbeds of clastics in river facies and carbonate rock in ocean facies.It is indicated that mixing depositions belong to"facies mixing",affected mainly by regional tectonic uplift,rise of the global sea level,and the dynamics of water medium in the basin. Regional sea level periodic changes and progradational sequences probably resulted from the intense uplift of the old land called Cathaysia.The classification and name of mixed sediments are also discussed in the present study.Interbeds and alternated beds of clastic and carbonate beds are named"hunji sequence",a new genetic term.It is suggested that hunji rock means a special sediment event of mixing terrigenous clastics and carbonates instead of a name of a specific rock. 相似文献
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The Formation and Distribution of the Marine Hydrocarbon Source Rock in the Tarim Basin, NW China 总被引：8，自引：7，他引：1
There are significant differences in type and distribution between marine source rock and continental source rock. According to the iithology, the Cambrian-Ordovician source rock in the Tarim basin is divided into two types： the carbonate source rock and the mud source rock. The two sets of source rocks are developed mainly in three sets of formations, Lower-Middle Cambrian carbonate source rock and mud source rock, Lower-Middle Ordovician mud source rock and Upper Ordovician lime mud source rock. The stratigraphic and areal distributions of the source rocks are controlled by the altitude and the sedimentary facies respectively. The mud source rock is developed in slope-semi deep sea environment. The source rock developed in the slope sedimentary environment is related with the anoxic environment and the one developed in semi deep sea has a close relationship with the up-flowing sea water. The carbonate source rock is developed mainly in platform slope of highstand systems tract and it is usually intimately associated with the salt rock. The Lower-Middle Cambrian carbonate source rock is developed mainly in the Bachu, Tazhong, Tangguzibasi and Yingmaili areas. The Lower-Middle Cambrian mud source rock is mainly developed in the areas east of the line of Kunan 1-Tadong 1. The Lower-Middle Ordovician mud source rock is developed mainly in the east slope of the Manjiaer depression. The carbonate source rock of Early Ordovician is developed mainly in the platform slope of highstand systems tract, such as the south margin of Tabei, the north slope of Tazhong, the Bachu area and Keping area. 相似文献
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《Applied Geochemistry》2002,17(3):163-183
The combined chemical composition, B and Sr isotopes, and the basic geologic setting of geothermal systems from the Menderes Massif in western Turkey have been investigated to evaluate the origin of the dissolved constituents and mechanisms of water–rock interaction. Four types of thermal water are present: (1) a Na–Cl of marine origin; (2) a Na–HCO3 type with high CO2 content that is associated with metamorphic rocks of the Menderes Massif; (3) a Na–SO4 type that is also associated with metamorphic rocks of the Menderes Massif with H2S addition; and (4) a Ca–Mg–HCO3–SO4 type that results from interactions with carbonate rocks at shallow depths. The Na–Cl waters are further subdivided based on Br/Cl ratios. Water from the Cumalı Seferihisar and Bodrum Karaada systems are deep circulated seawater (Br/Cl=sea water) whereas water from Çanakkale–Tuzla (Br/Cl<sea water) are from dissolution of Messinian evaporites. Good correlations between different dissolved salts and temperature indicate that the chemical composition of the thermal waters from non-marine geothermal systems is controlled by: (1) temperature dependent water–rock interactions; (2) intensification of reactions due to high dissolved CO2 and possibly HCl gasses; and (3) mixing with overlying cold groundwater. All of the thermal water is enriched in B. The B isotopic composition (δ11B=2.3‰ to 18.7‰; n=6) can indicate either leaching of B from the rocks, or B(OH)3 degassing flux from deep sources. The large ranges in B concentrations in different rock types as well as in thermal waters from different systems suggest the water-rock mechanism. 87Sr/86Sr ratios of the thermal water are used to differentiate between solutes that have interacted with metamorphic rocks (87Sr/86Sr ratio as high as 0.719479) and carbonate rocks (low 87Sr/86Sr ratio of 0.707864). 相似文献
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根据岩石沉积类型、物源供给、成因机制和沉积序列 ,结合区域地质特征 ,将兰坪盆地三叠系划分为陆相火山泥石流、河流相、三角洲相、潮坪相、浅海陆棚相、碳酸盐台地相和深水盆地相7种主要沉积类型。通过对沉积相的详细分析 ,恢复其古地理格架和面貌 ,探讨岩相古地理的变迁历史 ,从而表明三叠纪早期到晚期 ,其古地理经历了陆相环境→碎屑海盆→碳酸盐海盆到碎屑海盆的转换 ,即两次海侵 海退旋回。早期的海域分布范围较小 ,晚期的海域分布范围较宽 ,并成为统一的海盆。 相似文献
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下扬子盆地石炭纪的岩石学特征及沉积相 总被引：5，自引：0，他引：5
位于扬子板块东部的下扬子盆地，在石炭纪时，为被动大陆边缘的陆表海沉积，陆源碎屑来自于北边的胶南古陆和南边的江南古陆东延部分─—皖浙赣古陆。石炭系分为上、下两统。早石炭世，盆地南部宣城、广德等地主要发育碎屑岩，中部巢县、南京一带以及北部滨海、洪泽一带为碎屑岩和碳酸盐岩沉积。从南往北，金陵期从滨岸碎屑岩相→开阔海台地碳酸盐岩相→潮坪碳酸盐岩和碎屑岩相；高骊山期为滨岸平原沼泽碎屑岩相→浅海陆棚碎屑岩相→海岸萨布哈白云岩、石膏、碎屑岩相；和州期盆地南部隆起，中部到北部为礁及礁后泻湖一潮坪碳酸盐岩相→开阔海台地碳酸盐相。晚石炭世主要是碳酸盐沉积，黄龙期从滨岸石英砾岩相→潮坪白云岩相→开阔海台地碳酸盐岩相；船山期是黄龙期开阔海台地碳酸盐岩相的继续，以发育核形石生物碎屑颗粒岩为特征。整个盆地的岩相带均以ＮＥＥ—ＮＥ方向展布。 相似文献
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皖南地区晚震旦世陡山沱期岩相古地理 总被引：2，自引：0，他引：2
皖南地区在晚震旦世早期早时发生海侵,沉积了含碳、含硅的陆源碎屑岩,为浅海盆地相沉积;早期晚时,沉积了碳酸盐岩和碳酸盐岩夹粘土岩沉积,为台坡和台盆相沉积,其沉积相变化和古地理分异与当时基底性质、同沉积构造和碳酸盐建隆作用密切相关。 相似文献