caa a22 4500 469129360 CHVBK 20180323133200.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF00321842 doi (NATIONALLICENCE)springer-10.1007/BF00321842 Goguel Reiner Industrial Research Ltd., P. O. Box 31 310, Lower Hutt, New Zealand aut Group separation by solvent extraction from silicate rock matrix of Nb, Mo, Ta, and W at low levels for ICP-MS [Elektronische Daten] [Reiner Goguel] Summary: The extraction efficiency from silicate rock solutions in HF of Nb, Mo, Ta, and W as a function of fluoride activity in HCl solution, 3 mol/l, was investigated. At pF 3.5, N-benzoyl N-phenylhydroxylamine (BPHA) dissolved in CHCl3 proved to be an ideal system for the separation of the four analyte elements from the rock matrix after HF dissolution. All major rock constituents except for titanium are left behind in the aqueous phase. Values for the distribution ratios are 500±100 for all four elements allowing cross calibration in ICP-MS between enriched isotopes of Mo and W added to the samples before dissolution (isotope dilution) and the neighbouring monoisotopic elements Nb and Ta. Previously such high distribution ratios have been reported for Mo only because Nb, Ta, and W are not normally available as reactive ions due to hydrolysis unless directly released from fluoride complexes by downwards adjustment of fluoride activity of the solution in the presence of BPHA. Analytical data from 20 geochemical reference standards document the practical value of the described analytical procedure. Using ICP-MS and BPHA-pentanol solutions standards, superior detection limits are demonstrated by Nb, Ta, and W values in the sub ppm range obtained for some ultrabasic rock standards for which reference values are not yet available. Using ICP-MS and BPHA-pentanol solutions, superior detection limits are demonstrated by concentration values in the sub ppm range obtained for some ultrabasic rock standards for which reference values are not yet available. Springer-Verlag, 1992 Fresenius' Journal of Analytical Chemistry Springer-Verlag 344/7-8(1992-07-01), 326-333 0937-0633 344:7-8<326 1992 344 216 https://doi.org/10.1007/BF00321842 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00321842 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Goguel Reiner Industrial Research Ltd., P. O. Box 31 310, Lower Hutt, New Zealand aut NATIONALLICENCE 773 0- Fresenius' Journal of Analytical Chemistry Springer-Verlag 344/7-8(1992-07-01), 326-333 0937-0633 344:7-8<326 1992 344 216 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer