... in aqueous solvent has been studied by spectrophotometric method. The composition, the mechanism of complex formation have been established. The molecular absorptivity and the stable constant ... (1999). A STUDY ON THE COMPLEX FORMATION OF ER(III) WITH 1-(2-PYRIDYLAZO)-2-NAPHTOL (PAN) BY SPECTROPHOTOMETRIC METHOD Nguyen Dinh Luyen College of Pedagogy, Hue University ... Univ., Teacher’s College, Yangsu Peop. Rep. China 225002. Guangpu shiyanshi 1997, 14(3); Chemical Abstract, Vol 127, No.10, 1444619 (1997). 9 SUMMARY The complex formation of Er(III)...