Effect of Impurities (Fe3+ and Al3+) on the Temperature of Sodium Tripolyphosphate Formation and Polymorphic Transformation

Food multiphosphates-preparation and properties

Test results of the equilibrium between potassium mono- (ortho), di-, and triphosphates present in products of condensation of potassium orthophosphate mixtures, with regard to the molar ratio K/P, are discussed. Tests were performed within the molar ratio K/P range of 1.5 to 2.0. Qualitative determinations of changes in phase composition of products from thermal condensation at 450 degrees C, including changes in the K/P ratio within the tested range, were performed using the X-ray powder diffraction method. Qualitative analysis was performed using a combination of classical and HPLC methods. The range of K/P ratios was determined within which the main product obtained was pentapotassium triphosphate, which meets the criteria of the food industry.