Determination of uranium and radium in phosphate rock and technical phosphoric acid

1986 ◽  
Vol 324 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Farouk T. Awadalla ◽  
Fathi Habashi



1980 ◽  
Vol 63 (2) ◽  
pp. 208-210
Author(s):  
Terry C Woodis ◽  
J R Trimm ◽  
John H Holmes ◽  
Frank J Johnson

Abstract A method for determining uranium, based on extraction with trioctylphosphine oxide and measurement by argon plasma emission spectrometry at 424.17 nm, is described. Results from the argon plasma method compare favorably with results from other methods and are within 1 standard deviation of the composite average of all methods used in an 11-laboratory study.



1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.



Author(s):  
Guangya Zheng ◽  
Jupei Xia ◽  
Zhengjie Chen

: China primarily contains medium and low-grade phosphorus ores that are used to produce phosphoric acid. Here, we provide an overview of phosphoric acid production processes, including wet, thermal, and kiln methods, as well as the fundamental principles, major equipment, and technological aspects of each process. Progress in the kiln method using lowgrade phosphate rock is described, which involves the KPA and CDK processes. The literature shows that the addition of admixtures adds great competitiveness to kiln phosphate production methods and has considerable development prospects.



1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.



1941 ◽  
Vol 141 (1) ◽  
pp. 311-323
Author(s):  
F. Schlenk ◽  
T. Schlenk
Keyword(s):  




1954 ◽  
Vol 26 (6) ◽  
pp. 1060-1061 ◽  
Author(s):  
J. A. Brabson ◽  
W. D. Wilhide


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