[pt] O exame de mineralograma capilar fornece as concentrações de elementos tóxicos e essenciais no cabelo. O uso de produtos capilares, além de poderem representar uma fonte de exposição, é possível que causem alterações na composição mineral do cabelo. Neste trabalho, amostras de cabelo natural foram submetidas a tratamentos com diferentes tinturas e, posteriormente, analisadas seguindo a metodologia pré-estabelecida para determinação multielementar por espectrometria de massas com plasma indutivamente acoplado (ICP-MS). A composição elementar do cabelo humano natural foi comparada com as determinadas nas mesmas amostras de cabelo submetidas a tratamentos com diferentes tintas. Utilizando o teste estatístico Kruskal-Wallis, foi possível identificar diferenças significativas (p < 0,05) para os elementos Na, K e Mg, cujas concentrações aumentaram (de 100 a 5000x) após o uso das tinturas permanentes e semipermantes, enquanto para os cabelos que foram submetidos a tratamentos com corantes naturais isso não foi observado. Alguns elementos como Al, Fe, P tiveram decréscimo em suas concentrações (de 20 a 40%) após o uso desses tratamentos. Diante disso, foi possível determinar que alguns elementos são transferidos ou removidos do cabelo após o uso de determinados produtos, confirmando que tratamentos estéticos podem interferir nos resultados do exame do mineralograma capilar, devendo ser avaliada a necessidade da realização do mesmo em pacientes com cabelo tingido ou a possibilidade de aguardar por, pelo menos, 3 meses sem o uso de tratamentos permanentes antes da coleta da amostra para realização do exame. / [en] The hair mineral analysis test reports the concentrations of toxics and essential elements inside the hair structure. The utilization of hair care products, in addition to being able to represent an exposure source, also can be responsible for certain changes in the mineral composition of the hair. In present work, natural hair samples were treated with different dyes and, posteriorly, studied following the pre-established protocol for multi-element analysis by means of inductively coupled plasma mass spectrometry (ICP-MS). Hence, the element compositions of natural human hair after different treatments were compared. With the help of the Kruskal-Wallis statistical test, it was possible to identify significant differences (p < 0.05) for the elements, such as Na, K and Mg. Their concentrations increased from 100 to 5000x after the use of permanent and semipermanent dyes, while in the case of the hair samples treated with the natural dye no significant difference was observed. The concentrations of some elements, such as Al, Fe, P decreased (from 20 to 40%) after the respective treatments. Therefore, it was established that some elements are transferred or removed from the hair after the use of certain products, confirming that aesthetic treatments can interfere the results of the hair mineral analysis test. It reasons testing in patients with dyed hair or the possibility of waiting for about 3 months without the use of permanent treatments before sample collection for the analysis.

I weave figurative tapestries, working with themes regarding our relationship to the wild, both in nature and ourselves. I dye my yarns with mushrooms and plants I pick in the forest. I go through this trouble because I want the material to carry a story within itself, I see it as giving it life. This method makes the work divided in three main steps: the foraging, the dyeing, and the weaving.

Pectin has a long history as a food additive. However, elucidation of its fine structural and property relationships remains elusive. Recent research has focused on pectin's ability to complex with divalent heavy metals to aid in characterizing it. Commercial pectins of unknown composition were obtained from local grocers. Purified pectin samples from orange peel, lemon peel, and apple pomace, each of low and high levels of methyl esterification and of unknown distribution pattern were also purchased. Instead of metal complexation, several highly absorbing dyes such as Ruthenium Red, Nile Blue, and Acridine Orange were used to complex with the pectins and their resulting UV-Vis spectral patterns were employed to determine if one can characterize the different pectins. Chemometric methods are also included to aid in distinguishing them apart.

Synthetic dyes that are used as color additives in foodstuffs are regulated by the Food and Drug Administration (FDA) under the Food, Drug, and Cosmetic Act (FD&C). The use of synthetic dyes not approved by the FDA, or the addition of dyes approved by the FDA above their maximum concentration limits in foodstuffs necessarily constitutes illegal food adulteration. Recently, rhodamine B (RhB), a bright-pink synthetic dye not approved for use in foodstuffs, has become an adulterant of interest due to its discovery in a large variety of food samples, and its identity as a potential carcinogen. Numerous chromatographic and spectroscopic methods have been developed for the analysis of RhB in food samples, as well as standard methods available for the analysis of synthetic dyes. However, due to the complexity of real food samples and the chemical diversity of synthetic dye concomitants, comprehensive chromatographic methods tend to be time consuming and expensive. Herein, we report a method for the determination of RhB in foodstuffs for the screening of real samples prior to subsequent full-blown chromatographic analysis, saving valuable time and resources. This screening method employs thin-layer chromatography (TLC) as a separation method, and, due to the strong yellow-orange fluorescence exhibited by RhB when excited with ultraviolet or green light, direct fluorescent measurement of RhB on the TLC plate using a fiber optic probe coupled to a commercial spectrofluorometer or to an instrumental set up for laser-induced fluorescence measurements. Qualitative analysis of RhB is based on its retardation factor, excitation and fluorescence spectra, and fluorescence lifetime. Quantitative measurements are made directly from the TLC plate to provide analytical figures of merit comparable to traditional fluorometric methods in liquid solution. The ability of the new method to determine RhB in food samples is then demonstrated with the analysis of chili powder.

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