Cloud point extraction of lead in saliva via use of nonionic PONPE 7.5 without added chelating agents

LUCONI, MARTA OLGA; SILVA, MARÍA FERNANDA; OLSINA, ROBERTO; FERNANDEZ, LILIANA

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2000 vol. 51 p. 123 - 129

0039-9140

A new micelle-mediated phase separation of metal ions to preconcentrate trace levels of lead as a prior step to itsdetermination by flame atomic spectroscopy has been developed. The methodology is based on the cloud pointextraction of lead with PONPE 7.5 in the absence of chelating agent. The chemical variables affecting the sensitivityof the extractive-spectrometric procedure were evaluated in detail, optimised and successfully applied to thedetermination of lead in saliva samples. Under the optimal conditions, a %E higher than 99.9 was achieved. Theproposed method showed linear calibration within the range: 0.6–4 mg ml1 Pb(II). The sensitivity was 0.053 mgml1. The method has been applied to the determination of lead in human saliva. The nature of the extracting speciesas well as the location of lead in the micelle were studied. The analytical performance of the proposed method clearlysatisfies the typical requirements for control processes. © 2000 Elsevier Science B.V. All rights reserved.