4TH-ORDER DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF LEAD WITH 1,10-PHENANTHROLINE AND ROSE-BENGAL

Higher order derivative techniques are mainly used in deconvoluting th e overlapping absorption spectra of various analytes in their determin ation. The procedure utilizing higher order derivatives in molecular a bsorption spectrophotometry essentially are based on the formation of either binary or ternary complex formation. This paper deals with four th order derivative spectrophotometric procedure for the determination of traces of lead based on the liquid-liquid extraction of ternary io n association complex lead with 1,10-phenanthroline and rose bengal in to chloroform. The ternary ion associate is stable for over 24 hours. The developed procedure is simple, rapid, reliable and allows the dete rmination of as low as 20 ppb of lead in sea water samples.