Exploring potentialities of the HR-CS FAAS technique in the determination of Ni and Pb in mineral waters

Volnei Resta Amorim Filho,Vanessa Pezza Franzini,José Anchieta Gomes Neto

doi:10.26850/1678-4618eqj.v33.1.2008.p49-56

Volnei Resta Amorim Filho, Vanessa Pezza Franzini + Show 1 more

Open Access

https://doi.org/10.26850/1678-4618eqj.v33.1.2008.p49-56

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Abstract

National Health Surveillance Agency (ANVISA) established in the decree number 54 maximum allowed levels for Ni and Pb in mineral and natural waters at 20 μg L-1 and 10 μg L-1, respectively. For screening analysis purposes, the high-resolution continuum source flame atomic absorption spectrometry technique (HR-CS FAAS) was evaluated for the fast-sequential determination of nickel and lead in mineral waters.Two atomic lines for Ni (232.003 nm – main and 341.477 nm – secondary) and Pb (217.0005 nm – main and 283.306 nm - secondary) at different wavelength integrated absorbance (number of pixels) were evaluated. Sensitivity enhanced with the increase of the number of pixels and with the summation of the atomic lines absorbances. The main figures of merit associated to the HR-CS FAAS technique were compared with that obtained by line-source flame atomic absorption spectrometry (LS FAAS). Water samples were pre-concentrated about 5-fold by evaporation before analysis. Recoveries of Pb significantly varied with increased wavelength integrated absorbance. Better recoveries (92-93%) were observed for higher number of pixels at the main line or summating the atomic lines (90-92%). This influence was irrelevant for Ni, and recoveries in the 92-104% range were obtained in all situations.

Highlights

Drinking water is one of the main sources of contamination for humans and animals by toxic metals due to the large consumption [1,2]
This paper reports on the evaluation and application of the high-resolution continuum source flame atomic absorption spectrometry technique in the determination of Ni and Pb for water screening analysis
It should be mentioned that the calculated characteristic concentration (Co) obtained with 3 pixels at the main line (38.3 μg L-1) is close to that furnished by the manufacturer (40.0 μg L-1)

Summary

Introduction

Drinking water is one of the main sources of contamination for humans and animals by toxic metals due to the large consumption [1,2]. This new system either allows the use of two different strategies to improve the sensitivity: a) summation of absorbance signals of main and secondary atomic lines resulting in a new calibration function and b) integration of the absorbance signal over the center pixel by including part of the line wings, which is the same of increasing the number of pixels.

Results

Conclusion