Geological samples rocks

Geology Dating of geological samples - rocks and minerals Rb- Sr, Sm- Nd, 187Re 1870s, 238y 206p 3 ... 

In addition to the aforementioned methods, TLC in combination with other instrumental techniques have also been used for quantification of inorganic species. For example, two-dimensional TLC coupled with HPLC has been utilized for the separation and quantification of REEs in nuclear fuel fission products using silaiuzed silica gel as layer material [60]. In another interesting method, REEs in geological samples have been determined by ICP-AAS after their preconcentration by TLC on Fixion plates [32]. TLC in combination with neutron activation has been used to determine REE in rock samples on Eixion 50 x 8 layers with the sensitivity limit of 0.5 to 10 pg/g for 10- to 30-mg samples [41]. A combination of TLC and A AS has been utilized for the isolation and determination of zinc in forensic samples [27]. 

Pickett DA, Murrell MT, Williams RW (1994) Determination of femtogram quantities of protactinium in geologic samples by thermal ionization mass spectrometry. Anal Chem 66 1044-1049 Pietruszka AJ, Carlson RW, Hauri EH (2002) Precise and accurate measurement of Ra- °Th- U disequilibria in volcanic rocks using plasma ionization multicollector mass spectrometry. Chem Geol 188 171-191... 

Frequently two or more species are found together in the same geologic sample. As pressure-temperature conditions become more severe, the mineralogy becomes more simple, feldspar appears and finally within the limits of clay mineral stabilities only calcic zeolites are found. However, the calcic minerals are generally confined to rocks of basic... 

Closer to home, Ceo and C70 have been observed in geological samples of an unusual carbon-rich metamorphic rock known as shungite.[Bu92] The... 

The dithiol method has been applied for determining molybdenum in plant material [166], milk [167], sea water [168], biological materials [3,43,169], foodstuffs 169,170], silicate rocks [32,43,169,171], geological samples [172], tungsten and its compounds [173], niobium and tantalum [174], copper [175], and steel 169]. 

Uranium was determined in phosphoric acid [156] and in ores [157,158] with the use of PAN. The PAR method was applied for determining uranium in natural waters [92,94], sewage [94], rocks and waters [159], geological samples and biological materials [22,36], monazite sands [160], tin [161], and phosphoric acid [96]. 

Bio-Rad AGlx8 (100-200 mesh) was characterized by high selectivity for Pd(II), Pt(IV) and Au(III) ions (the partition coefficient values were 10 , 10, 10 for Au(III), Pt(IV) and Pd(II) ions, respectively), and therefore it could be applied for removal of noble metal ions from the environmental and geological samples, among others, from rocks, ores as well as dust and road dust [132]. 

Geochemical implications-T iq results of this study predict that 90, 99 and 99.9% of the initial amount of Pr or Ph in the geological samples must be thermally decomposed to obtain positive shifts in of 1.4 ( 0.4), 2.8 and 4.2%o, respectively. As already described, Bjor0y et al (1992) observed maximum positive carbon isotope shifts of 1.4-3.4%o for Pr and Ph in their laboratory hydrous pyrolysis of sedimentary rocks. We calculated the extent of thermal... 

An optical multichannel analyzer was used to obtain both peak height and peak area and was corrected for background. Results indicate either peak height or peak area can be used analytically except under electronic overload conditions. The method was used with a U. S. Geological Survey rock sample to determine Al, Fe, Ca, and Ti. The multielement technique compared favorably with concentrations of the four elements as reported by the U. S. Geological Survey. 

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