Avaliação de sorvente MIP em sistema de microextração hifenado ao HPLC-DAD, para determinação de taninos condensados em amostras de casca de jabuticaba (Myrciaria cauliflora)
Nenhuma Miniatura disponível
Data
2022-02-21
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Jabuticaba (Myrciaria cauliflora) is a fruit widely consumed in Brazil and of great nutritional
importance. Among the compounds of this fruit are the condensed tannins, which have already
been widely investigated regarding their chemical, biological and pharmaceutical properties,
which makes the extraction and isolation of these compounds of great economic and environmental
importance. According to the literature, the extraction of tannins from jabuticaba for isolation in
separation techniques has been carried out by conventional methods such as solid phase extraction
(SPE). However, these techniques have a limited selectivity, in addition, a high volume of solventes
is necessary, which consequently generates a large amount of waste. Thus, it is necessary to
research more selective and ecologically correct methods. Thus, the present work proposed the
development and optimization of an online extraction method based on molecularly imprinted
polymers (MIP) used in a capillary column for the isolation and identification of condensed tannins in jabuticaba peel. Therefore, catechin was used as a template molecule for MIP and non-imprinted polymer (NIP) was synthesized for comparison studies. The sorbent characterization was performed using scanning electron microscopy (SEM), nitrogen desorption and adsorption
analysis, transmission electron microscopy (TEM), infrared spectroscopy (FTIR),
thermogravimetry (TG) and diffraction X-ray (XRD). The data obtained with the characterization
of the phase showed similarity with the literature, regarding to the possibility of applying these
materials as an extractor phase in liquid chromatography with diode array detector(HPLC-DAD).
When evaluating the applicability of the column filled with the molecularly printed polymer in
HPLC-DAD, it was noted that it presented good results for the extraction of catechin, especially
when compared to the non-imprinted polymer. The results of the method optimization indicated
that the mobile phase flow of 20 µL min-1 and injection volume of 40 µL were the best in terms of
asymmetry and peak resolution, in addition to maintaining the extraction efficiency, decreasing
the generation of organic residues. On the other hand, the figures of merit evaluated showed
greater selectivity in the MIP in relation to the NIP for catechin, coefficients of variation from 2.6
to 7.3% between extractions, indicating excellent reproducibility of the columns and preconcentration factor of the MIP phase of 5.14%. Regarding the reuse capacity of the columns, a
value of relative standard deviation of 3.83% was found, indicating that the columns can be used
more than 40 times without losing the extraction efficiency, which is consistent with the result
obtained for the memory effect, in which the solvent chromatogram showed no peaks at the same
retention time for catechin. The quantification of tannins condensed in the matrix using the vanillin
method by the UV-vis spectrum at 500 nm, indicated a content of 59.1 µg mL-1 of the compounds
present in jabuticaba's aqueous extracts based on the standard curve of catechin constructed in
the concentrations of 0.01 to 1 mg mL-1, which showed relevance in terms of the choice of this
matrix. Furthermore, the analyzes performed by HPLC-DAD for the real samples showed
efficiency of the MIP column for catechin extraction, eliminating the interferents and concentrating the analyte.
Descrição
Palavras-chave
Citação
CARDOSO, A. T. Avaliação de sorvente MIP em sistema de microextração hifenado ao HPLC-DAD, para determinação de taninos condensados em amostras de casca de jabuticaba (Myrciaria cauliflora). 2022. 75 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Goiânia, 2022.