Modified Extraction Procedure for Direct Available P2O5 in Fertilizer

1980 ◽  
Vol 63 (3) ◽  
pp. 546-550 ◽  
Author(s):  
Rose A Sweeney
Keyword(s):  
Soluble Fraction ◽  
Extraction Procedure ◽  
Work Load ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
Official Method ◽  
Triple Superphosphate ◽  
Water Soluble Fraction ◽  
Average Recovery ◽  
Relative Standard

Abstract A modification of the direct available extraction procedure for P2O5 in fertilizer is presented. The modified extraction is used in our laboratory as a screening procedure to reduce work load associated with the lengthy official method. It is applicable to samples containing diammonium phosphate or other materials except triple superphosphate. Phosphorus is extracted from fertilizers with neutral ammonium citrate without prior removal of the water-soluble fraction. Samples are extracted by shaking 1 hr at 65°C on a water bath. The extract is cooled, diluted to volume, mixed, and an aliquot is taken for analysis. Average recovery of P2O5 from 9 selected Magruder samples by the modified extraction vs. the current official extraction was 99.5%, with a range of 98.7–99.9%. This study shows that the recovery of available P2O5 is not influenced by the level of CI P2O5 in the sample. Relative standard deviations for the modified extraction ranged from 0.20 to 0.86% with an average of 0.58%; relative standard deviation for the official extraction ranged from 0.30 to 0.89% with an average of 0.57%.

Evaluation of Methods for Determining Available P2O5 in Fertilizers

1977 ◽  
Vol 60 (3) ◽  
pp. 702-705
Author(s):  
Frank J Johnson ◽  
James A Farley
Keyword(s):  
Soluble Fraction ◽  
Water Soluble ◽  
Official Method ◽  
Water Soluble Fraction ◽  
Indirect Determination ◽  
Evaluation Of Methods

Abstract The official AOAC methods for the direct and indirect determination of available P2O5 in fertilizers were compared. The quantity of water-soluble P2O5 removed prior to the citrate extraction has a significant effect on the final available P2O5 result. The quantity of water and the technique used to remove the water-soluble fraction were evaluated. The results indicate that 250 ml and an active wash are necessary to obtain acceptable values for available P2O5. The official method for direct available P2O5 was revised editorially.

Effects of Washing Technique in the Determination of Citrate-Insoluble and Available P2O5 in Triple Superphosphate

1969 ◽  
Vol 52 (5) ◽  
pp. 946-949
Author(s):  
W J Harwell ◽  
E B Hewitt
Keyword(s):  
Soluble Fraction ◽  
Initial Step ◽  
Water Soluble ◽  
Available Phosphorus ◽  
Triple Superphosphate ◽  
Water Soluble Fraction ◽  
Insoluble Phosphorus

Abstract The results of the citrate-insoluble and available phosphorus determinations are influenced by the technique used in the initial step, the removal of the water-soluble fraction. An “active” washing technique in removing all of the water-soluble fraction will give lower values for citrate-insoluble phosphorus and higher values for available phosphorus.

Copper Distribution in Shaxi River Sediments

2011 ◽  
Vol 356-360 ◽  
pp. 1440-1444
Author(s):  
Li Hua Zhang ◽  
Cheng Song Zheng
Keyword(s):  
Heavy Metal ◽  
Soluble Fraction ◽  
Extraction Procedure ◽  
Water Soluble ◽  
Wastewater Discharge ◽  
Surficial Sediments ◽  
Iron And Steel ◽  
Water Soluble Fraction ◽  
Steel Factory ◽  
Downstream Distance

For the surficial sediments sampled from the Shaxi River in Sanming, Fujian Province, China, the distribution characteristic of heavy metal copper in surficial sediments were investigated. The microwave digestion result showed that the concentration of Cu in surficial sediments ranged from 26.95 mg/kg to 74.76 mg/kg. The results of modified BCR sequential extraction procedure showed that heavy metal copper in the surficial sediment was mainly associated with residual and reducible fractions. The fractions of copper sampled near the wastewater discharge were in the order of residual > reducible > oxidizable > acid soluble > water soluble fraction, and in the order of residual > reducible > acid soluble > oxidizable > water soluble fraction in samples away from the wastewater discharge. The results indicated that the concentration and fraction of pollutant copper were significantly correlative to the wastewater discharge of some iron and steel factory around the Shaxi River, which varied obviously with the downstream distance increasing to the wastewater discharge. The reducible and oxidizable fractions decreased with the downstream distance increasing to the wastewater discharge of iron and steel factory, however, the acid soluble fraction increased with the distance increasing.

Impact of Rice Flour Cold-Water-Soluble Fraction Removal on Gelatinization and Pasting Properties

2014 ◽  
Vol 91 (5) ◽  
pp. 473-481 ◽  
Author(s):  
Guiai Jiao ◽  
Xiangjin Wei ◽  
Gaoneng Shao ◽  
Lihong Xie ◽  
Zhonghua Sheng ◽  
...  
Keyword(s):  
Cold Water ◽  
Soluble Fraction ◽  
Rice Flour ◽  
Pasting Properties ◽  
Water Soluble ◽  
Water Soluble Fraction

FRACTIONATION OF LIVETIN AND THE MOLECULAR WEIGHTS OF THE α- AND β-COMPONENTS

1957 ◽  
Vol 35 (4) ◽  
pp. 241-250 ◽  
Author(s):  
W. G. Martin ◽  
J. E. Vandegaer ◽  
W. H. Cook
Keyword(s):  
Light Scattering ◽  
Soluble Protein ◽  
Soluble Fraction ◽  
Egg Yolk ◽  
Water Soluble ◽  
Water Soluble Fraction ◽  
Molecular Weights ◽  
Water Soluble Protein ◽  
Hen Egg Yolk ◽  
Hen Egg

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.

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