Banca de DEFESA: JÉSSICA DA CONCEIÇÃO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA DA CONCEIÇÃO DA SILVA
DATE: 31/10/2022
TIME: 08:00
LOCAL: GOOGLE MEET
TITLE:

Development of analytical methodology based on Paper-based Analytical Devices (PADs) for the simultaneous determination of Pb(II) and Hg(II). 

KEY WORDS:

Microfluidic Systems; Colorimetric detection; heavy metals; µPAD.

PAGES: 95
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

In recent years, there has been a growing ecological and global public health concern associated with environmental contamination by potentially toxic metals, as metal ions enter ecosystems as dissolved entities in water systems and fall into the category of human carcinogens, and non-toxic pollutants. biodegradable, resulting in harmful effects on health, genetics, nutrition and ecosystems. Among all water contamination, heavy metal ions, such as Hg2+ and Pb2+, can cause serious health problems in animals and humans, such as cancer, liver dysfunction, endocrine and nervous system disorders, among others. other problems. Several analytical methods have been reported for the determination of these metals, including electrochemical, spectrophotometric and fluorescence. Although these methods are suitable for the determination of these analytes in different samples, they have some disadvantages, including high cost and reagent consumption, laborious operation, complex equipment and trained professionals. Thus, methods that overcome these disadvantages are necessary and required. Paper-based analytical microdevices (µPADs) have emerged as a powerful tool for presenting features such as low cost, portability, low reagent consumption and ease of use. Thus, in this work, an analytical device based on on-site test paper for the simultaneous determination of Hg2+ and Pb2+, in natural water samples from the São Francisco River in the riverside town of Penedo is presented. The µPADs were associated with colorimetric detection, based on the reaction between the analytes in question and the dithizone colorimetric probe, generating a color proportional to the concentration of this metal. It was observed that the system behaves better at pH = 9.0, with a boric acid buffer solution. In addition, the influence of the color channels of the R, G, B and RGB scales was studied in this work, it was observed that for the method proposed in this work the red channel presented the best result for both metals. In the linearity assessment, the values of the red channel had a correlation greater than 0.991 for mercury and 0.989 for lead. The detection limit determined was 0.99 µg/mL and the quantification limit was 3.0 µg/mL, with a linear range of 1 – 20 µg/mL for mercury. For lead, the detection limit found was 0.74 µg/mL with a quantification limit of 2.25 µg/mL, with a linear range of 1-25 µg/mL.

BANKING MEMBERS:
Presidente - 1127609 - DIOGENES MENESES DOS SANTOS
Interna - 426640 - FABIANE CAXICO DE ABREU GALDINO
Externa à Instituição - FABRICIA DA ROCHA FERREIRA - SEE
Interna - 1904678 - JANAINA HEBERLE BORTOLUZZI
Externo à Instituição - PHABYANNO RODRIGUES LIMA - IFAL
Interna - 1646575 - RUSIENE MONTEIRO DE ALMEIDA
Interno - 1609640 - VINICIUS DEL COLLE