scholarly journals Quantitative Determination of Lead and Uranium from Geological Samples

2004 ◽  
Vol 52 (4) ◽  
pp. 213-218 ◽  
Author(s):  
Gen SHIMODA
Keyword(s):  
Quantitative Determination ◽  
Geological Samples

Precise Quantitative Determination of Niobium at Low Level Concentrations in Geological Samples by WD-XRF

1999 ◽  
Vol 23 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Joël Etoubleau ◽  
Pierre Cambon ◽  
Henri Bougault ◽  
Jean-Louis Joron
Keyword(s):  
Quantitative Determination ◽  
Geological Samples ◽  
Low Level

The synthesis of nor- and bisnorlupanes

1991 ◽  
Vol 69 (3) ◽  
pp. 570-577 ◽  
Author(s):  
Amal Wahhab ◽  
Margaret Ottosen ◽  
Frank W. Bachelor
Keyword(s):  
Quantitative Determination ◽  
Key Words ◽  
Ring Closure ◽  
Efficient Synthesis ◽  
Geological Samples ◽  
Oil Shales

In the course of our studies on geochemical biomarkers we required a series of lupane standards. We report here an efficient synthesis of lupane (1) in three steps from betulin (3) in an overall yield of 47.2%. 17β(H)-28-Norlupane (2) was obtained in 90% purity employing Barton's method for the decarboxylation of 3-oxolupan-28-oic acid (10). 24,28-Bisnorlupane (4) and 24-norlupane (5) were obtained by a series of reactions involving formation of the oxime, the seconitrile, the epoxynitrile, ring closure, and finally a Wolff–Kishner reduction of the C3 carbonyl to the methylene. Also, to aid in the quantitative determination of these lupanes from oil shales and geological samples, 3-deuterolupane (6) and 2,3-dideuterolupane (7) were needed, and a method for their preparation is reported. Key words: lupane, 24-norlupane, 28-norlupane, 24,28-bisnorlupane, 3-deuterolupane, 2,3-dideuterolupane.

Quantitative determination of longitudinal and transverse cross-relaxation rates

1999 ◽  
Vol 96 (9/10) ◽  
pp. 1608-1615
Author(s):  
T. E. Malliavin ◽  
H. Desvaux ◽  
M. A. Delsuc
Keyword(s):  
Quantitative Determination ◽  
Cross Relaxation ◽  
Relaxation Rates

Quantitative Determination of Gallic acid and Cyanidin-3-O-Glucoside within Sumac Extracts by HPLC-MS/MS

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
M Koşar ◽  
F Göger ◽  
N Kırımer ◽  
KHC Başer
Keyword(s):  
Quantitative Determination ◽  
Gallic Acid
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