scholarly journals A preliminary report on the rapid fluorimetric determination of uranium in low-grade ores

10.3133/tei47 ◽  
1950 ◽  
Keyword(s):  
Preliminary Report ◽  
Low Grade ◽  
Fluorimetric Determination

The fluorimetric determination of cerium and terbium

1989 ◽  
Vol 54 (3) ◽  
pp. 616-621 ◽  
Author(s):  
Záviš Holzbecher
Keyword(s):  
Rare Earth ◽  
Detection Limit ◽  
Rare Earth Elements ◽  
Fluorimetric Determination ◽  
Fluorescence Maximum ◽  
Relative Standard ◽  
And Shifts ◽  
Hcl Medium ◽  
Fold Excess

It has been found that phosphoric acid decreases the first excitation maximum of Ce(III) at 256 nm, increases the second excitation maximum at 297 nm and shifts the fluorescence maximum from 350 to 346 nm. Under optimum conditions, with λexc = 297 nm and λem = 346 nm, Ce(III) can be determined fluorimetrically with a detection limit of 1.2 ng ml-1 in 12M-H3PO4 medium. No interference was observed from a 20-200 fold excess of HCl, H2SO4, Na, K, NH4+, Al and the rare earth elements. HNO3 interferes and Ce(IV) and Fe(III) interfere strongly. It follows from the stereofluorograms of Ce and Tb that the spectra of the two elements are practically independent. The detection limit for Tb(III) in 0.02-2.5M-H2SO4 medium for λexc = 222 nm and λem = 494 nm is 33 ng ml-1. No interference was observed from a 5-20 fold excess of Al3+ and the other rare earth elements. The determination is slightly less sensitive in H3PO4 or HCl medium. The relative standard deviation of the measurement for 10 ng ml-1 Ce(III) or 50 ng ml-1 Tb(III) is about 3%.

Fluorimetric Determination Of Mercury (Ii) Based On The Inhibition Of The Enzymatic Activity Of Urease

1994 ◽  
Vol 27 (5) ◽  
pp. 867-878 ◽  
Author(s):  
D. W. Bryce ◽  
J. M. Fernández-Romero ◽  
M. D. Luque de Castro
Keyword(s):  
Enzymatic Activity ◽  
Fluorimetric Determination

Fluorimetric determination of tin at the nanograms per millilitre level in canned beverages

The Analyst ◽  
1985 ◽  
Vol 110 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Soledad Rubio ◽  
Agustina Gómez-Hens ◽  
Miguel Valcárcel
Keyword(s):  
Fluorimetric Determination

Flow-injection fluorimetric determination of vitamin K1 based on a photochemical reaction

Talanta ◽  
1999 ◽  
Vol 50 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Tomás Pérez-Ruiz ◽  
Carmen Martı́nez-Lozano ◽  
Virginia Tomás ◽  
Jesús Martı́n
Keyword(s):  
Flow Injection ◽  
Photochemical Reaction ◽  
Vitamin K1 ◽  
Fluorimetric Determination
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