Resumen

BRUHN, CARLOS G.; VILCHES, CAROLINA  y  CID, HERNAN J.. OPTIMIZATION OF FLAME ATOMIC ABSORPTION SPECTROM- ETRY WITH PRECONCENTRATION BY FLOW-INJECTION ON-LINE SORBENT EXTRACTION OF CADMIUM AND LEAD IN BIOLOGICAL MATERIALS. Bol. Soc. Chil. Quím. [online]. 1999, vol.44, n.3, pp. 321-335. ISSN 0366-1644.  http://dx.doi.org/10.4067/S0366-16441999000300009.

A flow-injection (FI) system with a minicolumn of bonded silica with octadecyl groups (C-18) to collect diethyldithiocarbamate complexes of Cd and Pb in reference solutions and in acid-digested hair and blood solutions was developed and evaluated by flame atomic absorption spectrometry (FAAS). The system was optimized by multivariate method, based on a factorial experimental design in two levels, selecting eight parameters that mostly affected the expected analytical signal. The detection limits (3´s_BL/slope, 60 s preconcentration) were 0.7 and 5 µg/l for Cd and Pb, respectively and the sampling frequency was 40 samples/h. Effects of interfering ions are discussed. The methodology was validated by analysis of certified reference materials of hair and blood for Pb, and by recoveries of Cd and Pb spikes performed in hair and blood samples. Results for Pb agreed well with certified values and recoveries were satisfactory (103% in blood and 100% in hair). Also, the recovery of Cd in hair was fair (107%); however, in blood it was not quantitative (22%)

Palabras llave : Cadmium; lead; preconcentration by sorption; flow injection flame atomic absorption spectrometry; hair and blood.