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91.
High‐resolution gamma ray spectrometry was exploited to locate the potential radioactive targets at Kab Amiri granite pluton, Central Eastern Desert, Egypt. The Kab Amiri pluton forms a concentric granitic body of monzogranite to syenogranite composition intruded into mafic‐ultramific rocks. To identify and detect anomalous concentrations of natural radioactive elements in the study area, contour maps of equivalent uranium (eU ppm), equivalent thorium (eTh ppm), potassium (K%) and their geochemical ratios (eU/Th, eTh/K and eU‐eTh/3.5) as well as standard deviation map of uranium were constructed and interpreted. Qualitative and quantitative interpretations of the spectrometric survey data revealed the presence of seven radioactive anomalies in the south of the studied area. These anomalies could be related to the prevailing faulting directions NE and ENE fault trends. The southernmost anomalous zone is related to high episyenitization and uranium concentrations. It exhibits a sharp increase in the eU concentrations reaching 370 ppm resulting in a high eU/eTh ratio reaching 4.5 and characterized by oval shape trending in the NE direction. Constructing the contour map of the (eU‐eTh/3.5) was helpful in defining the trends of uranium migration and enabling the delineation of the limit between the negative contours (leaching) and positive contours (deposition). 相似文献
92.
铋的原子吸收光谱分析进展 总被引:4,自引:0,他引:4
文章对1985年以来用原子吸收光谱法测定Bi的情况进行了综述,着重介绍了用氢化物发生法、石墨炉法和火焰法测Bi时,为了提高灵敏度所采用的各种氢化物发生装置及根据不同试样所使用的各种分离富集手段。主要参考文献101篇。 相似文献
93.
顶空进样-固相微萃取测定饮用水源水中吡啶 总被引:1,自引:1,他引:1
用75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取头顶空萃取15 mL水样中的吡啶,萃取物用气相色谱-质谱法进行分离和检测,采用内标法和质谱的选择离子监测模式进行定量分析。优化了顶空进样-固相微萃取条件,获得较佳的萃取温度(58.0℃)和萃取时间(40 min)。在优化的条件下,方法检出限为1.5 μg/L,标准曲线的线性相关系数为0.9994,线性范围为2.5~50.0 μg/L;饮用水源水和纯水加标平均回收率为75.6%~81.3%,相对标准偏差(RSD,n=6)为9.60%~12.21%。使用顶空萃取方式可避免样品基体的复杂性,有利于保护萃取头涂层,同时无需使用有机萃取溶剂;使用质谱检测器可减小假阳性带来的影响。顶空进样-固相微萃取操作简单、环保、灵敏度高,适合用于饮用水源水中吡啶的监测分析。 相似文献
94.
95.
Determination of Halogens (F, Cl, Br, I), Sulfur and Water in Seventeen Geological Reference Materials 总被引:5,自引:0,他引:5
Fluorine, chlorine, bromine, iodine and sulfur were determined in seventeen geological reference materials after extraction by pyrohydrolysis. Fluorine, Cl and S (as sulfate ions) were determined in the extraction solution by ion chromatography with detection limits of around 0.2 mg l−1 . Bromine and I were measured by ICP-MS with detection limits of 1 μg l−1 for Br and 0.1 μg l−1 for I. For rock samples, using normal extraction conditions (500 mg of sample and 100 ml of final solution) detection limits were 40 mg kg−1 for F and Cl, 15 mg kg−1 for S, 0.2 mg kg−1 for Br and 0.02 mg kg−1 for I. These detection limits may be improved by increasing the amount of sample and hence the concentration of the final solution. Water was also determined using an extraction technique based on H2 O degassing, reduction on zinc at 1000 °C and H2 manometry. Our results for fluorine, chlorine, sulfur and water are in good agreement with literature data. Very few reference materials have recommended values for bromine and especially for iodine. Among the analysed samples, three are new reference materials: BHVO-2, BCR-2 and AGV-2. 相似文献
96.
氯化钠存在下氯化亚锡—罗丹明B—水体系浮选分离铱 总被引:5,自引:1,他引:5
研究了Ir(Ⅲ)在NaCl存在下SnCl2-罗丹明B-水体系中的浮选行为,在1.0mol/L HCl介质中,Ir(Ⅲ)与Pd,Pt,Rh,Au同时被浮选,Ir(Ⅲ)的浮选率为99.2%,并与常见贱金属离子分离,被浮选分离的Ir可采用原子吸收法测定,结果与火试金分离富集法相符。精密度试验,相对标准偏差(RSD,n=5)<3%。 相似文献
97.
Kevin R. Chamberlain Axel K. Schmitt Susan M. Swapp T. Mark Harrison Norbert Swoboda-Colberg Wouter Bleeker Tony D. Peterson Charles W. Jefferson Andrei K. Khudoley 《Precambrian Research》2010
An in situ U–Pb SIMS (IN-SIMS) method to date micro-baddeleyite crystals as small as 3 μm is presented with results from three samples that span a variety of ages and geologic settings. The method complements ID-TIMS geochronology by extending the range of dateable crystals to sizes smaller than can be recovered by physical separation. X-ray mapping and BSE imaging are used to locate target grains in thin section, followed by SIMS analysis on a CAMECA ims 1270, using the field aperture in the transfer column to screen out ions from host phases. Internal age precisions for the method are anticipated to range from 0.1% for Precambrian rocks to 3–7% for Phanerozoic rocks. Results establish a 2689 ± 5 Ma age for mafic dikes in the Wyoming craton, USA, a 1540 ± 30 Ma age for a subaerial lava flow from the Thelon Basin of northern Canada, and a 457 ± 34 Ma age for mafic dikes in the platform sequence of southeastern Siberia. The method is ideal for relatively non-destructive dating of small samples such as extraterrestrial rocks and precious terrestrial samples. 相似文献
98.
99.
使用粉末压片法制样,X射线荧光光谱法测定地质样品中氯,探讨了样片背衬、样片接受X光照射时间对测量结果的影响。Cl的精密度(RSD,n=12)小于10%。Cl的方法检出限为12μg/g,采用国家一级标准物质分析验证方法,其结果与标准值相符。 相似文献
100.
作者对激光热透镜光谱法测定微量钼进行了研究.试验表明,在丙酮介质中,Mo6+能被还原成Mo5+并形成钼蓝同多酸,最大吸收彼长在670um处,利用He-Ne激光器输出的632.8um的激光作光源,进行微量钼的热透镜法分析测定.两酮的存在能增强热透镜信号强度。钼含量在0.01—2.0μg/mL范围内与激光热透镜信号强度呈良好的线性关系,方法检出限为0.005μg/mL钼,已用于地质样品中微量钼的高灵敏度测定.结果满意. 相似文献