Original scientific paper
PHYSICO-CHEMICAL EVALUATION OF FEED PHOSPHATES AS A CRITERION OF THEIR CLASSIFICATION
Dorota Jamroz
; Wrocław University of Environmental and Life Sciences; Department of Animal Nutrition and Feed Quality, Wroclaw, Poland
Agnieszka Gajda-Janiak
; Wrocław University of Environmental and Life Sciences; Department of Animal Nutrition and Feed Quality, Wroclaw, Poland
Zbigniew Wzorek
; Cracow University of Technology; Institute of Inorganic Chemistry and Technology, Cracow, Poland
Zygmunt Kowalski
; Cracow University of Technology; Institute of Inorganic Chemistry and Technology, Cracow, Poland
Abstract
Chemical composition of 341 charges – samples of fodder phosphates, their physico-chemical properties (solubility in different solvents), harmful elements content, phase composition and thermal analysis of 150 selected samples of phosphates were determined. Average solubility of monocalcium phosphates (% P2O5 in relation to total P2O5) (in%) amounted to: in water 74.8 – 82.1; in 2% citric acid from 96.6 to 98.3; in 0.4% HCl 94.8 – 98.8 and in neutral ammonium citrate 93.6 – 97.1. Solubility of dicalcium phosphates amounted to (in %): in water from 1.4 to 7.4; in 2% citric acid 50.9 – 98.5; in 0.4% HCl 78.7 – 92.3 and in neutral ammonium citrate 70.3-85.1. Average solubility of monosodium phosphates amounted to (in %): in water 0.1-89.6; in 2% citric acid 25.0 – 90.0; in 0.4% HCl 26.9 – 47.7 and in neutral ammonium citrate 27.7 – 90.2. Solubility of the remaining groups of phosphates (tricalcium, calcium-magnesium and sodium-calcium phosphates) amounted to (in %): in water from 0.1 to 25.8; in 2% citric acid from 25.1 to 95.7; in 0.4% HCl from 26.9 to 56.2 and in neutral ammonium citrate from 23.1 to 79.3. Hydrated monocalcium phosphates with admixture of both hydrated and dehydrated dicalcium phosphate were characterized by the highest solubility in water. In the group of dicalcium phosphates the lowest solubility in 0.4% HCl was stated for dehydrated forms, while the highest solubility was observed in hydrated phosphates. Solubility in water or in 0.4% hydrochloric acid together with the roentgenographical and thermogravimetrical investigations as well as solubility in 2% citric acid and in neutral ammonium citrate are good and cheap methods for identifying by precise the quality of phosphates.
Keywords
feed phosphates; physico-chemical quality
Hrčak ID:
67884
URI
Publication date:
8.4.2011.
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