Abstract: A process wherein an aqueous solution containing dissolved phosphorus is seeded with iron oxide and a clay additive, if necessary, and with the electrolyte cation Al.sup.+.sup.3, the latter acting to associate the dissolved phosphate with the iron oxide and clay to form a coagulum. The coagulum is then removed from the solution magnetically.

Abstract: A process wherein a solution is allowed to fall from the end of a capillary tube in the presence of a gradient field of an applied force field (magnetic or electric). If the fluid contains ions that are susceptible to the applied field, then the content of those ions can be correlated to the change in the specific characteristics of the capillary drop (i.e., the drop weight or equivalently the drop volume). This finds use as an assay technique for those susceptible ions, and it further can be used to give information as to the degree of susceptibility that the ions show to the applied force field.