Evaluation of the potential of laser-induced breakdown spectrometry (LIBS) in the analysis of assai pulp

Abstract

Laser-Induced Breakdown Spectroscopy (LIBS) has become a very attractive and widely explored technique in analytical chemistry. Despite the advantages, quantitative analysis is not an easy task, and has been considered the "Achilles' heel" of the technique. This fact is duet to the complex nature of laser-sample interaction which causes strong matrix interference. One way of minimizing this problem is to perform instrumental optimization and employ adequate calibration procedures. Research on LIBS applications on the analysis of complex samples is increasing, but there is no study regarding the samples of assai pulp, which is topic of this project. Brazil is the largest producer, consumer and exporter of assai pulp. Assai is very popular and shows high economic rentability in Brazil, generating 25 thousand direct jobs, and over R$40 million in revenues, anually. The assai pulp trade has reached foreign powers such as the United States, Japan and China, and the expectation is that it continues to expand. The guarantee of the quality of this product depends on the knowledge of its chemical and biochemical composition, so that it is possible to ensure the commerce of a safe product, free of adulterations. Therefore, the present project aims to evaluate the potentiality of LIBS in the analysis of assai pulps. It is intention the evaluation of the influence of instrumental and sample parameters on the quality of the analytical results, as well as the calibration strategies to enable quantitative analysis by using this technique. This study is part of a project in collaboration with Prof. Dr. Monica Felipe Sotelo and Prof. Dr. Neil Ward, both from the University of Surrey (UoS, Guildford, Surrey, UK), with whom we have collaborated since august 2017 when UPGN 2017 project (Association of total mineral content and metal speciation with the healing properties of berries - 01/08/2017 - 31/07/2018) was approved.