Lithium spectrometry

The commercial ores, beryl and bertrandite, are usually decomposed by fusion using sodium carbonate. The melt is dissolved in a mixture of sulfuric and hydrofluoric acids and the solution is evaporated to strong fumes to drive off siUcon tetrafluoride, diluted, then analy2ed by atomic absorption or plasma emission spectrometry. If sodium or siUcon are also to be determined, the ore may be fused with a mixture of lithium metaborate and lithium tetraborate, and the melt dissolved in nitric and hydrofluoric acids (17). 

Instrumentation. Traditional methods of alpha and beta spectrometry instrumentation have changed little over the past decade. Alpha spectrometric methods typically rely on semi-conductor or lithium-drifted silicon detectors (Si(Li)), or more historically gridded ion chambers, and these detection systems are still widely used in various types of uranium-series nuclide measurement for health, environmental, and... 

Benzwi [409] determined lithium in Dead Sea water using atomic absorption spectrometry. The sample was passed through a 0.45 pm filter and lithium was then determined by the method of standard additions. Solutions of lithium in hexanol and 2-ethylhexanol gave greatly enhanced sensitivity. 

The metals were coprecipitated with lead-ammonium pyrrolidine dithio-carbamate and detected by X-ray spectrometry following neutron activation. Magnetic fields deflect the p rays while the X rays reach the silicon (lithium) detector undeviated. The detectors have low sensitivity to y rays. The concentration of cobalt found by this method was 1.3 xg/l, about one-fifth of that measured previously, while that of copper, 2.0 xg/l, agreed with results obtained by some previous workers. The concentration of mercury was 1.2 xg/l. 

The introduction of high-resolution, high-efficiency /-ray detectors composed of lithium-drifted germanium crystals has revolutionised /-measurement techniques. Thus, /-spectrometry allows the rapid measurement of relatively low-activity samples without complex analytical preparations. A technique described by Michel et al. [25] uses Ge(Li) /-ray detectors for the simultaneous measurements of 228radium and 226radium in natural waters. This method simplifies the analytical procedures and reduces the labour while improving the precision, accuracy, and detection limits. 

Chassery et al. [97] studied the 87Sr/86Br composition in marine sediments, observing excellent agreement between results obtained by ICP-MS and thermal ionisation mass spectrometry. Low level a-spectrometry with lithium drifted germanium detectors has been used to determine 90strontium in seawater [59]. 

Z. Zhou, S. Ogden and J.A. Leary, Linkage position determination in oligosaccharides mass spectrometry (MS/MS) study of lithium-cationized carbohydrates, J. Org. Chem., 55 (1990) 5444-5446. 

In another study, Streitwieser and Van Sickle (1962) measured the secondary /3-deuterium KIEs for the formation of carbanions from hydrocarbons with lithium cyclohexylamide in cyclohexylamine at 49.9°C. The rate constants needed for determining these KIEs for the formation of the carbanion (reaction (34)) were obtained by analysing the deuterium in the ethylbenzene recovered from the reaction at various times by mass spectrometry. 

Moriguti T, Nakamura E (1993) Precise lithium isotope analysis by thermal ionization mass spectrometry using lithium phosphate as an ion source. Proc Japan Acad Sci 69B 123-128 Moriguti T, Nakamura E (1998a) High-yield lithium separation and precise isotopic analysis for natural rock and aqueous samples. Chem Geol 145 91-104... 

Nance WB, Taylor SR (1976) Rare earth element patterns and crustal evolution—I. Australian post-Archean sedimentary rocks. Geochim Cosmochim Acta 40 1539-1551 Nishio Y, Nakai S (2002) Accurate and precise lithium isotopic determinations of igneous rock samples using multi-collector inductively coupled plasma mass spectrometry. Anal Chim Acta 456 271-281 Nishio Y, Nakai S, Hirose K, Ishii T, Sano Y (2002) Li isotopic systematics of volcanic rocks in marginal basins. Geochim Cosmochim Acta 66 A556... 

Sun XF, Ting BTG, Zeisel SH, Janghorbani M (1987) Accurate measurement of stable isotopes of lifiiium by inductively coupled plasma mass spectrometry. Analyst 112 1223-1228 Svec HJ, Anderson AR (1965) The absolute abimdances of the lithium isotopes in natiwal sources. Geochim... 

Wheat CG, Mottl MJ (2000) Composition of pore and spring waters from Baby Bare Global implications of geochemical fluxes from a ridge flank hydrothermal system. Geochim Cosmochim Acta 64 629-642 White DE, Thompson JM, Fournier RO (1976) Lithium contents of thermal and mineral waters. In Lithium Resources and Requirements by the Year 2000. Vine JD (ed) U.S. Geol Surv Prof Pap 1005 58-60 Xiao YK, Beary ES (1989) High-precision isotopic measurement of lithium by thermal ionization mass spectrometry. Int J Mass Spect Ion Proc 94 101-114... 

Trace element analysis was carried out on the ash by fusing with lithium metaborate, followed by dissolution in 10 % hydrochloric acid. The resulting solution was analysed using atomic emission and absorption spectrometry (AA). The method has been described previously (9). 

The study of the interactions between organic compounds and aUtali-metal cations, in the gas phase, is related to many topics such as ion solvation, catalysis and molecular recognition. Furthermore, mass spectrometry has been used for the analyses of organolithium compounds and supramolecular assemblies that contain lithium cations. Alkali cationization is an important ionization technique, implemented for the analyses of a wide range of organic compounds. Finally, gas-phase studies are also useful for the quantitative determination of lithium cation affinity. The interaction between lithium cation and organic substances is thus related to different aspects of gas-phase chemistry and mass spectrometry. 

The same group studied the lithium cation basicities of a series of compounds of the general formula R R R PO, i.e. phosphine oxides, phosphinates, phosphonates and phosphates, by using Fourier Transform Ion Cyclotron Resonance (FTTCR) mass spectrometry. A summary of their results is shown in Figure 4. The effect of methyl substitution on LCA as well as the correlation between LCA and PA was also investigated by Taft, Yanez and coworkers on a series of methyldiazoles with an FTICR mass spectrometer. They showed that methyl substituent effects on Li binding energies are practically additive. 

Carbohydrates show a considerable affinity toward alkali cations, which are frequently used for their mass spectral analyses. Lithium cation exhibits specific affinity toward glucose, as has been detected by electrospray ionization mass spectrometry. The experimental results were found to be consistent with the ab initio theoretical calculations and confirm the following order of stability of the M+-glucose complexes [gl-Li] > [gl-Na]+ > [gl-K]+4 . 

Fujii developed a method for detecting radical species in the gas phase with the use of lithium ion attachment to chemical species. Li ions have been chosen as reactant ions, because the affinity of the species is highest among all the alkah metal ions. The author also explored some of the unique properties of Li ion attachment in mass spectrometry. This technique provides mass spectra of quasi-molecular [R + Li]+ ions formed by lithium-ion attachment to the radical species under high pressure . ... 

Ahmed, S. Jabeen, N. Rehman, E. Determination of Lithium Isotopic Composition by Thermal Ionization Mass Spectrometry. Anal. Chem. 2002, 74, 4133-4135. 

Elecfrothermal atomization atomic absorption spectrometry, lithium, 36 54 Electrovalent compounds, high oxidation states of, stability, 5 10-11... 

Fixation, COj, reaction modeling, 43 426-431 Flame emission spectrometry, lithium, 36 54 Flash photolysis, 46 106, 137, 139-140 organometallics, 19 81-83... 

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