It has been shown that the addition of excess phosphate to calcium solutions causes redistribution of the calcium into smaller aerosol size ranges and significant reductions in the median calcium aerosol diameters. Addition of lanthanum as a releasing agent causes the median diameter for Ca aerosol to return to the value observed in the absence of phosphate and a concomitant reduction in the median diameter of the phosphate aerosol. Such redistribution effects cause changes in the phosphate-calcium concentration ratios and the stoichiometries of the calcium-phosphorus entities that can be formed. Thus, the effect of phosphate on calcium absorbance may be an enhancement for smaller aerosol diameters and a suppression for larger diameters.
K. G. Kronholm and R. K. Skogerboe, "Aerosol Ionic Redistribution: The Calcium-Phosphorus Solute Vaporization Effect Revisited," Appl. Spectrosc. 40, 1161-1166 (1986)