Flow injection spectrophotometric analysis of lead in human saliva for monitoring environmental pollution

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

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2001 vol. 54 p. 45 - 52

0039-9140

A new highly sensitive, simple and low-cost methodology for the direct determination of Pb (II) with 2-(5-bromo-2-pyridylazo)-5-dimethylaminophenol in ethanolic medium has been developed. The absorption spectroscopy of thecomplex has been examined in detail, and the chemical variables affecting the sensitivity of procedure studied,optimized and applied to the determination of trace amounts of lead in human saliva. Under the optimal experimentalconditions, a precision of 1.61104 mg cm2 was achieved, the molar absorptivity being (o) 5.6104 l mol1cm1. An FI technique is proposed, and it is possible to determine trace levels of lead by injection into a steambuffered at pH 7.15, containing 70% ethanol: 30% Tris buffer 3.5103 mol l1 (pH7.2), 1104 mol l15-BrDMPAP. The FIA configuration allows the analysis of 45 samples per hour. The lower limit of detection (LOD)was 1107 mol l1. The calibration plot was linear at least within two orders of magnitude of lead concentration.The use of an HPLC pump for the FI analysis led to a substantial improvement in the analytical performance of themethod, which clearly satisfies the typical requirements for control processes. © 2001 Elsevier Science B.V. All rightsreserved.