scholarly journals AN ACCURATE METHOD FOR THE DETERMINATION OF PHOSPHORUS PENTOXIDE AS MAGNESIUM AMMONIUM PHOSPHATE

1927 ◽  
Vol 49 (4) ◽  
pp. 891-896 ◽  
Author(s):  
Wallace Morgan McNabb
1964 ◽  
Vol 47 (3) ◽  
pp. 420-428
Author(s):  
W M Hoffman

Abstract The official volumetric method is less suitable than other official methods for the determination of phosphorus in fertilizer and should be deleted. Because rapid and accurate gravimetric quinoline molybdate and photometric vanadomolybdate methods are available, the little-used official gravimetric magnesium ammonium phosphate method also should be deleted. Volumetric Ammonium Molybdate Method


1956 ◽  
Vol 29 (2) ◽  
pp. 664-671 ◽  
Author(s):  
M. E. Tunnicliffe

Abstract A critical evaluation of the molybdenum-blue method for the determination of orthophosphate and magnesium has been made and the conditions have been established for their quantitative determination in rubber latex. The precipitation of magnesium ammonium phosphate has been shown to be complete under the conditions of the test. For the conversion of phosphate to molybdenum blue, a comparison of several recommended reducing agents has shown that ferrous sulfate gives a stable and reproducible color which varies with the phosphate concentration according to Beer's Law. For the determination of total phosphorus, dry ashing of the sample with magnesium nitrate is proposed, followed by hydrolysis and a determination of the phosphate in the ash as molybdenum blue, as for magnesium. Free phosphate in latex serum is determined directly after coagulation and removal of interfering substances from the serum by cationic exchange.


2021 ◽  
Vol 937 (2) ◽  
pp. 022131
Author(s):  
N Bagnavets ◽  
A Zhevnerov ◽  
M Grigoryeva ◽  
T Pshenichkina

Abstract Phosphate fertilizers are widely used for growing crops. To obtain phosphoric fertilizers, phosphoric acid purified using organic solvents, one of which is 100% tributyl phosphate, is used. The authors of the paper have chosen this solvent to obtain purified phosphoric acid. Purification from impurities included the stages of extraction and reextraction. On the basis of the re-extract and chemically pure phosphoric acid, a phosphoric fertilizer magnesium-ammonium phosphate (MgNH4PO4) was synthesized and used in the greenhouse experiment. The greenhouse experiment consisted in growing a tomato crop included three options for fertilization. A comparative analysis of the stimulating effect of magnesium-ammonium phosphate, synthesized with the use of phosphoric acid of varying degrees of purification, on the yield of tomato culture has been carried out.The paper proposes a blister-colorimetric version of the determination of phosphate ions in a blister cell containing a mixture of dry reagents in the form of a bulk. The optimal conditions for carrying out colorimetry have been selected. The proposed method makes it possible to semi-quantitatively determine phosphorus in various objects without preparing reagent solutions, using a bulk packed in an ampoule or blister, and can be used to control phosphorus consumption by plants, which, in turn, allows regulating the introduction of nutrients in the form of dressings.


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