Resonance scattering spectroscopic study of the system of PMo12 heteropolyacid and rhodamin S

In the medium of 0.14 mol.dm(-3) H2SO4, PO43- and MoO42- react with rhodami n S to form an associated complex of PMo12 heteropoly acid-rhodamin S, whic h exhibits a sensitive resonance scattering peak at 610nm, Phosphorous conc entration in the range of 0.2 similar to 20 mu g.dm(-3) is linear to the in tensity of resonance scattering light, The results show that this method ha s high sensitivity and good selectivity. This method has been applied to th e analysis of phosphorous in water and tea samples. The analytical results are in agreement to those of oscillopolarography. This work demonstrates th at the primary cause of exhibiting resonance scattering peak is the formati on of unsoluble associated complex and the big size sol.