Characterization of soil phosphorus by anion exchange resin adsorption and P32-equilibration

1955 ◽  
Vol 6 (4) ◽  
pp. 391-408 ◽  
Author(s):  
F. Amer ◽  
D. R. Bouldin ◽  
C. A. Black ◽  
F. R. Duke
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Soil Phosphorus ◽  
Resin Adsorption

scholarly journals Determination of available soil phosphorus by chemical methods

1978 ◽  
Vol 50 (4) ◽  
pp. 305-316 ◽  
Author(s):  
Erkki Aura
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Soil Phosphorus ◽  
Phosphorus Uptake ◽  
Ammonium Fluoride ◽  
Acetate Solution ◽  
Phosphorus Status ◽  
Mineral Soils ◽  
Resin Method

Phosphorus uptake by oats in pot experiments was compared with phosphorus test values obtained for experimental soils. Phosphorus was extracted from the soil using acid ammonium acetate solution, Bray 1 solution, Olsen solution, ammonium fluoride, distilled water and anion exchange resin. Intensity values were determined by equilibrating the soils with 0.01 M CaCl2 solution. Soil samples were collected from 30 mineral soils. The best test for phosphorus status proved to be the anion exchange resin method. Good results were also obtained with simple water extraction. An advantage of the water and resin method is that the microstructure of the soil is not substantially changed when using these methods. An intensity measurement was not in itself sufficient for analysis of the phosphorus status, since the intensity drops rapidly when soil releases phosphorus.

Syntheses and Characterization of N-(Indolyl)pyridinium Salts and of Their Ylides

2014 ◽  
Vol 69 (5) ◽  
pp. 605-614 ◽  
Author(s):  
Nazar Pidlypnyi ◽  
Sandra Kaul ◽  
Sebastian Wolf ◽  
Martin H. H. Drafz ◽  
Andreas Schmidt
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Pyridinium Salts ◽  
Ring Transformation ◽  
Pyrylium Salts

3-Methylindole reacts with pyridines in the presence of NBS to give indol-2-yl-pyridinium salts which were converted into their ylides by an anion exchange resin in its hydroxide form. Indol-3- amine was subjected to a nucleophilic ring transformation with pyrylium salts which resulted in the formation of indol-3-yl-pyridinium salts, the 2,4,6-trimethylpyridinium derivative of which proved to be unstable. The 2,4,6-triphenylpyridinium derivate was deprotonated to the corresponding ylide. The isomeric indol-2-yl and indol-3-yl derivatives are cycloimmonium ylides which are members of the compound class of heterocyclic mesomeric betaines (MB). By contrast, the ylide of indol- 2-yl-pyrrolidinium is a cycloammonium ylide. It was prepared by reaction of 3-methylindole with pyrrolidine in the presence of NBS, followed by deprotonation.

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