Cation-exchange separation of strontium from manganese and other elements in citrate media

Mn(IT) can be eluted quantitatively with 0.067M ammonium citrate at pH 7.0 or 7.5 from a column of AG50W-X8 cationexchange resin (200-400 mesh), and separated from Sr which is retained. Mg, Ca, Cu(II), Zn and Co(II) accompany Mn(II). From citric acid solutions up to 1M (20%) and from 5 % citric acid solution at pH 2.2 both Mn(II) and Sr are retained very strongly. This is in agreement with some previous work but disagrees with a recent statement by others that 5 % citric acid at pH 2.2 is an effective eluting agent for Sr.