Banca de QUALIFICAÇÃO: JÉSSICA DA CONCEIÇÃO DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA DA CONCEIÇÃO DA SILVA
DATE: 24/08/2022
TIME: 10:00
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: 71
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 Pb2+ and Hg2+can cause serious health problems in animals and humans, such as cancer, liver dysfunction, endocrine and nervous system disorders, among other problems. Several analytical methods have been reported for the determination of Pb2+ and Hg2+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 devices (PADs) 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 local test paper for the simultaneous determination of Pb2+ and Hg2+in natural water samples from the São Francisco River in the riverside town of Penedo is presented. The PADs were coupled to colorimetric detection, based on the reaction between these metals 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. Of the three types of layout discussed in this work, the one that stood out was the one that had detection zones with 2 mm thick hydrophobic barriers around them. The influence of the color channels of the R, G, B and RGB scales was also studied in this work, it was observed that for the method proposed in this work the red channel was the one that had the best result, both for Hg2+as well as for the Pb2+ . In addition, this methodology proved to be suitable for application in natural water samples and is a simple, cheap and fast alternative for the determination of the aforementioned metals. 

BANKING MEMBERS:
Presidente - 1127609 - DIOGENES MENESES DOS SANTOS
Interna - 426640 - FABIANE CAXICO DE ABREU GALDINO
Interna - 1904678 - JANAINA HEBERLE BORTOLUZZI
Externo à Instituição - PHABYANNO RODRIGUES LIMA - IFAL