Microwave-Assisted Solid Sampling Analysis Coupled to Flame Furnace Atomic Absorption Spectrometry for Cd and Pb Determination in Food-Contact Polymers

Alessandra Schneider Henn,Angelica Chaiani Frohlich,Cezar Augusto Bizzi,Vitoria Hagemann Cauduro,Erico Marlon De Moraes Flores,Marcos Leandro Silva Oliveira,Matheus Felipe Pedrotti

doi:10.3390/su14010291

Alessandra Schneider Henn, Angelica Chaiani Frohlich + Show 5 more

Open Access

https://doi.org/10.3390/su14010291

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Abstract

Microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry (MW-SS-FF-AAS) was used for Cd and Pb determination in food-contact polymer samples, with the aim of minimizing reagents and laboratory waste. Operational parameters, such as the FF tube design, the oxygen flow rate, the flame stoichiometry, the sample mass, among others, were evaluated and optimized. Calibration was performed using only reference solutions, and the limits of quantification were 1.7 and 4.6 μg g−1 for Cd and Pb, respectively. Accuracy was assessed by the analysis of certified reference materials (CRMs), and by comparison with the results obtained by inductively coupled plasma mass spectrometry after microwave-assisted wet digestion. The MW-SS-FF-AAS results for the CRMs showed no statistical difference with the certified values, and good agreement was observed with the results of the digestion method. The MW-SS-FF-AAS method was considered suitable for Cd and Pb determination in food-contact polymers. The concentrations of Cd and Pb in the analyzed samples varied from <1.7 to 628 μg g−1, and from <4.6 to 614 μg g−1, respectively. As sample digestion is not necessary, the use of concentrated acids can be avoided by using the proposed MW-SS-FF-AAS method, greatly reducing waste generation.

Highlights

Polymers currently represent one of the most important materials for society and they are used in the most diverse industrial segments, from the automotive to the packaging sectors
In order to overcome the microwave-induced combustion (MIC)-FF-AAS limitations, in a previous study [24], a portable microwave applicator device was developed and coupled with an FAAS spectrometer. This technique is called microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry (MW-SS-FF-AAS) and it was applied for Hg determination in polymer samples
The system was optimized in order to achieve high sensitivity and similar behavior between the solid samples and the reference solutions

Summary

Introduction

Polymers currently represent one of the most important materials for society and they are used in the most diverse industrial segments, from the automotive to the packaging sectors. Contaminants can be incorporated into polymers by the use of additives during manufacturing, such as stabilizers, plasticizers, lubricants, antimicrobial agents, antioxidizing agents, antistatic agents, pigments, and others [2,3]. Among these contaminants are elements such as Cd and Pb, which are of great concern because of their potential toxicity [4]. Developing suitable methods for the determination of potentially toxic elements in food-contact polymers is of considerable importance. Several techniques have been used for the determination of potentially toxic elements in polymers, such as flame and graphite furnace atomic absorption spectrometry (FAAS and GFAAS), inductively coupled plasma optical emission spectrometry (ICP-OES), and Sustainability 2022, 14, 291.

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