Evaluation of sample preparation methods for the determination of Cd, Cr and Pb in ceramic tableware by graphite furnace atomic absorption spectrometry

Abstract

This work presents a study involving the determination of Cd, Cr and Pb in ceramic tableware by graphite furnace atomic absorption spectrometry (GF AAS) using a simple and practical slurry sampling method. A central composite design (CCD) was used to optimize the slurry sampling conditions. The obtained results were confronted by the ultrasonic acid decomposition, evaluating the instrumental parameters relevant to the accuracy and precision. In addition, recovery measurements of the analytes were performed and ranged between 90% and 111% for both methods. The concentrations obtained were in the range from 0.04 to 184; 67 to 1395 and 42 to 5305 μg g⁻¹ for Cd, Cr and Pb, respectively. These concentrations were higher for some ceramic samples, which may be related to the raw material used for their manufacture and also due to the pigment used during the decoration process. In addition, the leaching study observed concentrations in the range from 0.07 to 1.68; 0.1 to 5.0 and 0.6 to 46.3 μg g^-1 for Cd, Cr and Pb, respectively, and there is a possibility of migration of these toxic metals from the ceramic materials to the food.

Keywords:

• ceramic tableware
• toxic metals
• slurry sampling
• acid decomposition
• graphite furnace atomic absorption spectrometry (GF AAS)
• central composite design (CCD)

Additional information

Funding

The authors are grateful to Agência Nacional de Vigilância Sanitária (ANVISA) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) through the MCTI/CNPq/ANVISA no 23/2012 (Process 403403/2012-0) for financial support. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - finance Code 001.