Browsing by Author "Pina, Mariana Almeida"
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- Avaliação da Segurança de Produtos Cosméticos: Pesquisa de Contaminantes em Extractos Usados como Ingredientes AtivosPublication . Pina, Mariana Almeida; Domingues, Valentina Maria FernandesThe increasing use of cosmetics by the population around the world, particularly in developed countries, has led to a huge demand for new ingredients obtained from natural sources due to their richness in bioactive compounds associated with skin benefits as well as new concerns related with the environment. This is particularly the case of extracts obtained from the shell of chestnut (Castanea sativa) shells that have been investigated as a new potential cosmetic ingredient. This by-product results from chestnut production and presents a bioactive composition rich in antioxidant compounds (such as catechin or gallic acid), which are of great interest for the cosmetic field. However, it is fundamental to guarantee that the extracts coming from shells, or from any other food by-product, are safe for consumers. Therefore, the principal goal of this work was to monitor the presence of some compounds present in the Regulation (EC) nº 1223/2009, concerning cosmetic products, in chestnut shells and chestnut shells extracts obtained by green extraction techniques (ultrasound-assisted extraction (UAE) and subcritical water extraction (SWE)). Considering this, the presence of organochlorines (OCPs), pyrethroids (PYRs) and organophosphorus (OPPs) pesticides families was evaluated in the chestnut shells as well as in the SWE and UAE extracts. For the analysis in the chestnut shells, the QuEChERS analytical method for contaminant extraction was developed and optimized. The optimization of this method was done in the cleaning step, where different sorbent combinations were tested, namely Cleanup 1 (CL1), Cleanup 2 (CL2) and Cleanup 3 (CL3). After analysing the recovery values and the matrix effect obtained when used the different combinations, it was concluded that CL2 offers better results for the OCPs and PYRs studies, while CL3 lids to better results for the OPPs. After validation, this method was applied to real samples and the obtained extracts were injected in the pesticide detection equipment, namely gas chromatograph with electron capture detector and gas chromatograph with the photometric flame detector. Although some compounds were detected, part of them were in concentrations below the limit of detection and, therefore, were considered as not detectable. The others, despite being present in concentrations between the limits of detection and quantification or even higher, are below the maximum residue limits defined by the European Union for chestnuts. Finally, the analysis of the extracts from the chestnut shells was performed. To prepare samples of these extracts, for subsequent analysis in gas chromatography, the solid-phase extraction method was used. Contrary to what was done regarding QuEChERS method, this methodology did not undergo any optimisation and consequent validation, since the analysis of these liquid extracts served only as a confirmation of the results obtained for the chestnut shells. Nevertheless, it should have been done in order to ensure that the method applied was the most appropriate for this purpose. This work allows to conclude that, partly similar to what was obtained for the chestnut shells, the UAE and SWE chestnuts extracts are free of pesticides, namely OCPs, PYRs and OPPs, thus being safe for a possible application in cosmetic products.