3RD ORDER DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF MERCURY(II) AS THE TERNARY COMPLEX WITH IODINE AND PYRONINE-G

This paper describes a third order derivative molecular absorption spectrophotometric procedure for the determination of traces of mercury based on the formation of ternary ion-association complex by reaction of mercury with pyronine G in the presence of iodide. The pink coloured ternary ion-association complex is readily formed in the pH range 1-7 and remained stable for 24 h. after stabilization with gelatin. The influence of various instrumental parameters and reaction conditions for maximum colour development are discussed. The few interfering ions can be masked by the addition of appropriate reagent solutions.