Microchips eletroforéticos de vidro com detecção condutométrica sem contato para análise de ânions inorgânicos em amostras reais
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2014-05-02
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Universidade Federal de Goiás
Resumo
This work describes the evaluation of commercial microchip electrophoresis
system for the analysis of inorganic ions in different real samples. The electrophoretic
separation was carried out in commercial glass microchip with integrated capacitively
coupled contactless conductivity detection (C4D). The optimization process was
performed ranging the concentration background electrolyte as well as detection
parameters, frequency and amplitude signal. Furthermore, analytical performance
was evaluated with linearity, repeatability and recovery study. The best separation of
chloride (Cl-), nitrate (NO3-), sulfate (SO42-) and nitrite (NO2-) was obtained with
mixture of lactic acid (30 mmolL-1) and histidine (15 mmolL-1). Frequency and
amplitude were ranged from 100 to 1200 kHz and from 1 to 100 Vpp, respectively.
Test with detection parameters was performed employed a classic univariate
approach. Frequency of the 1100 kHz and amplitude of 60 Vpp was found the best
condition for separation process. Quantitative analysis was performed in different real
samples as well as honey, sausage, biofertilizers, river water, tap water and
aquarium environment water. In honey sample found Cl-, NO3- e SO42-. Meia Ponte
River and João Leite stream was found Cl- e SO42-. These same species was also
found in sausage sample. In the analysis of aquarium environment water was
observed Cl-, NO3-, SO42- and NO2-. Besides the quantitative analysis, the monitoring
of inorganic ions (Cl-, NO3-, SO42- and NO2-) in aquarium environment with and
without fish. The water without fish was possible keep up with nitrification process in
the nitrogen cycle and to examine the conversion time of the species involved. On
the other hand, in analyses of water with fish the results showed an increase of
nitrate concentration over weeks and were possible quatify the nitrite in lethal level
for fish. According to the results achieved herein, it is possible to conclude that the
use glass electrophoresis chips associated with commercial instrumentation has
demonstrated good capability of performing quantitative analysis of important
environmental compounds in real samples.
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Citação
FREITAS, Camilla Benevides. Microchips eletroforéticos de vidro com detecção condutométrica sem contato para análise de ânions inorgânicos em amostras reais. 2014. 70 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Goiânia, 2014.