Banca de DEFESA: VITÓRIA APARECIDA PROCÓPIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VITÓRIA APARECIDA PROCÓPIO
DATE: 22/11/2022
TIME: 08:00
LOCAL: https://meet.google.com/gns-fpbv-iyp
TITLE:

HYPHENATION OF HPLC-DAD AND ICP-MS TECHNIQUES TO OBTAIN MOLECULAR AND ELEMENTARY INFORMATION OF BIOMOLECULES CONTAINING CHROMIUM

PAGES: 73
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Análise de Traços e Química Ambiental
SUMMARY:

Chromium (Cr) is the seventh most abundant element in the Earth's crust, and inorganic species with an oxidation state +3 and +6 are the most common. Cr(III) is considered an important micronutrient for the metabolism of carbohydrates, proteins and lipids. However, there are still doubts about its essentiality. In turn, Cr (VI) is a highly toxic species, considered mutagenic and classified as a Group 1 substance (carcinogenic to humans) by the International Agency for Research on Cancer (IARC). The combined HPLC-ICP-MS application can be used for quantitation and identification analysis of elements with hundreds of molecular formulas known in biota. The first element in which legislation adopted speciation was Cr. A wide variety of metalloproteins have been increasingly applied as biomarkers of exposure to different metals. There are few methods in the literature involving chemical speciation and detection of organic molecules, in relation to Cr, the literature becomes even more scarce. Therefore, this work aimed to develop a new analytical method through the coupling of HPLC-DAD with ICP-MS in order to obtain molecular and elemental information simultaneously, respectively, from a single sample injection. In the first step, a low-cost flow divider, made of acrylic, was developed aiming at optimally directing the sample to the detectors, enabling the HPLC-DAD/ICP-MS coupling. The Hamilton PRP-X100 anion exchange column was used in the speciation of Cr species. Through preliminary studies, the mobile phase flow rate was adjusted to 0.5 mL min^-1 and the NH₄NO₃ concentration at pH=7 was then set to 225 mM, allowing a satisfactory separation of the analytes and a chromatographic analysis in less than 8 minutes. Calibration curves were performed for aqueous solutions containing [Cr (III)-EDTA]^- and Cr (VI) complexes, at concentrations of 0.10; 0.20; 0.30; 0.40 and 0.50 mg L^-1 of each of the species. Both presented coefficients of determination (R²) greater than or equal to 0.9990 in both detectors (DAD and ICP-MS). The study followed with the application of the method in extracts of real samples, the effectiveness of the preparation of the extracts was evaluated from tests of recovery of the total determination of Cr in ICP-MS in two CRMs Água Natural (1640a - NIST) and Folha de Sugarcane (CRM-Agro FC_012017), being 99.67% and 85.39%, respectively. The LOD and LOQ in ICP-MS were also discussed along with the chromatographic parameters of selectivity and capacity factor. The method was then applied in the extracts of CRMs and in samples of food supplement, liver and tuna muscle containing Cr in its composition, the presence of possible biomolecules associated with Cr (III) and Cr (VI) species were evaluated, with response simultaneous detection of molecular (DAD) and elementary (ICP-MS) detectors. The biomolecules discussed during monitoring for Cr were phytochelatin and chromium picolinate. Finally, the work also discusses and evaluates the potential of the technique applied to other elements being iron, cobalt and sulfur associated with other biomolecules hemoglobin, cobalamin and phytochelatin, respectively.

BANKING MEMBERS:
Presidente - Interno ao Programa - 2046361 - BRUNO LEMOS BATISTA
Membro Titular - Examinador(a) Externo à Instituição - MARIA FERNANDA HORNOS CARNEIRO - PUC
Membro Titular - Examinador(a) Externo à Instituição - FERNANDA POLLO PANIZ
Membro Suplente - Examinador(a) Interno ao Programa - 1814655 - LUCIA HELENA GOMES COELHO
Membro Suplente - Examinador(a) Externo à Instituição - KATHARINA GRUNDLER