Determinação de ácidos orgânicos em amostras alimentícias e petroleômicas utilizando sistemas eletroforéticos
Nenhuma Miniatura disponível
Data
2022-06-30
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
This study describes the use of microchip electrophoresis coupled to contactless conductivity
detection for the determination of inorganic and organic anions for food and petroleomics
application. Also, describes the use of capillary electrophoresis coupled to mass spectrometry
for petroleomic application. Organic acids are responsible for several wines characteristics, such
as aroma, flavor, color and stability. Their analysis are important for monitoring fermentation
process and the quality of wines. 12 anions were detected and separated within 100 s, using a
buffer composed of 30 mmol L-1 OF 2-(N-Morpholino)ethanesulfonic acid, 15 mmol L-1 of
histidine and 0.05 mmol L-1 of cetyltrimethylammonium bromide (pH 5.8). 18 wine samples
were analyzed and it was possible to detect and quantify sulfate, phosphate, tartrate, maleate,
succinate, acetate and lactate. A multivariate approach was used to investigate the similarities
among anionic profile of the wines, and it was possible to discriminate samples mainly by grape
varieties, production region and winemaking process. Naphthenic acids are carboxylic acids
naturally occurring in crude oil with one or more ring structures. They are present in produced
water, which is the water obtained with petroleum during its prospection and are responsible
for corrosion, naphthenates deposition, and harmful to the environment when disposed of
without treatment. The acids benzoic, 1-naphthoic and 9-anthracenecarboxylic were separated
and detected using a microsystem electrophoresis coupled to contactless conductivity detection.
The analysis was performed within 140 s using a buffer composed of an equimolar mixture of
10 mmol L-1 of sodium carbonate and bicarbonate (pH 10.2). 5 samples of produced water were
analyzed and it was possible to detect and quantify 9-anthracenecarboxylic acid, demonstrating
to be an efficient tool for analysis of complex samples matrices for petroleum applications. In
this way, electrophoresis microchip proves to be a simple and portable analytical platform for
field analysis, proving to be promising for wine quality control and for monitoring the presence
of naphthenic acids in produced water samples. A capillary electrophoresis system coupled to a
mass spectrometer was also used to analyze naphthenic acids. It was possible to detect
cyclopentanecarboxylic acid, benzoic acid, cyclohexanebutyric acid, 1-naphthoic acid, decanoic
acid, 3,5-dimethyladamantane-1-carboxylic acid, 9-anthracenecarboxylic acid, pentadecanoic
acid and 2-methyl-octadecanoic acid within 13 min using a buffer composed of 40 mmol L-1 of
ammonium hydroxide, 32 mmol L-1 of acetic acid and 20% isopropanol (pH 8.6). Produced water
samples were analyzed and it was possible to identify and quantify cyclopentanecarboxylic,
benzoic, cyclohexanebutyric and decanoic acids. In this way, the proposed method
demonstrated to be efficient to detect naphthenic acids analysis in complex samples of produced
water using capillary electrophoresis coupled with mass spectrometry. The next steps of this
study are the evaluation of other acids in produced water samples for quantification of total
acids.
Descrição
Citação
PINHEIRO, K. M. P. Determinação de ácidos orgânicos em amostras alimentícias e petroleômicas utilizando sistemas eletroforéticos. 2022. 166 f. Tese (Doutorado em Química) - Instituto de Química, Universidade Federal de Goiás, Goiânia, 2022.