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- Campus Samambaia, Campus Colemar Natal e Silva, Campus Aparecida de Goiânia.
Submissões Recentes
Earwax as an alternative specimen for forensic analysis
(2017-03-24) Shokry, Engy Shokry Abdel Samie; Marques Júnior, Jair Gonzalez; Ragazzo, Paulo Cesar; Pereira, Naiara Zedes; Antoniosi Filho, Nelson Roberto
In this work, we presented, for the first time, earwax as an alternative forensic specimen for detecting 12 neuropsychotic drugs employing liquid chromatography–tandem mass spectrometry in positive and negative ion modes after straightforward extraction with methanol. The method was validated and standard curves were established by external calibration with correlation coefficients >0.99. All precision, accuracy, matrix effects, extraction recoveries, and carryover were within acceptable limits; limits of quantification were sufficiently low to quantify almost all the samples tested. To confirm the feasibility of the study, earwax specimens were collected from actual patients treated with different combinations of the 12 drugs and analyzed by our method; the 12 drugs could be quantified from the earwax specimens of the users successfully, showing usefulness of earwax specimens, because of its noninvasive sampling and the storage of drug(s) for relatively long time together with its being relatively less contaminated by environmental impurities. This study is pioneering; many detailed studies on earwax as an alternative specimen remain to be explored.
Nature of insoluble material found in the bottom of soybean biodiesel storage tank: chemical and microbiological approach
(2018) Cazarolli, Juciana Clarice; Boelter, Gabriela; Lima, Amanda Muliterno Domingues Lourenço de; Hengles, Thaisa Concha Vasquez; Correa, Camila; Peralba, Maria do Carmo Ruaro; Cavalcanti, Eduardo Homem de Siqueira; Bisol, Marcia Veroneze; Bezerra, Kelly da Silva; Antoniosi Filho, Nelson Roberto; Bento, Fatima Menezes
During biodiesel storage, chemical reactions may occur, producing sludges. The aim of this study was to characterize the chemical and microbial composition of the sludge found in a biodiesel storage tank. The material was collected in a biodiesel production plant. The sludge chemical characterization was performed by Fourier transform infrared (FTIR) spectroscopy, flame atomic absorption spectroscopy (FAAS), gas chromatography (GC), and the microbial investigation used culture-dependent techniques. The deteriogenic potential of the native microbial community was evaluated using the sludge as a microbial inoculum in a 60 day experiment. The microbial growth, biodiesel degradation, pH alterations, and the detection of esters in the aqueous phase were evaluated. The chemical analysis indicated the sludge composition as fatty acids esters and metallic ions; sterols glycosides were not detected. Seven bacteria and five fungi species were obtained from the sludge. The microbial growth analysis indicated that the native community does not have high biodiesel deteriogenic capacity.
Avaliação química, ecotoxicológica e genotoxicológica de águas de cavas de mineração a céu aberto
(2019-02) Bárbara, Viníciu Fagundes; Tavares, Maria Gizelda de Oliveira; D'Alessandro, Natália Cristina de Oliveira; Silva, Daniela de Melo e; Antoniosi Filho, Nelson Roberto
Artificial lakes formed in open pit mining areas are complex units and constitute emerging environmental liabilities arising from the mining industry. Although they are increasing in number in several parts of the world, they still form a recent and little studied environmental problem, especially regarding the quality and toxicity of its waters, which may represent worrying environmental risks. This study describes the results of the seasonal analysis of chemical, ecotoxicological and genotoxicological aspects of the waters of three disused gold mining pit lakes located in Mara Rosa, Goiás, Brazil. Samples were collected in profile in two different climatic seasons, winter and summer, and were chemically analyzed to determine their load of metals and anions. Ecotoxicological Tests and Comet Assays were also developed with fish of the Danio rerio species. The results indicated that the concentrations of the chemical species analyzed were predominantly increased in the surface-bottom direction and higher during the dry season. Lago Azul waters have been shown to be chemically more compromised as they are acidic and rich in potentially toxic analytes such as aluminum, cadmium, lead, copper, manganese, nickel, and zinc. No significant ecotoxicological alterations were identified for any of the analyzed samples, although, in genotoxicological terms, Lago Azul presented DNA damage from concentrations of 25% in the dry season and 50% in the wet season.
Development of methods to quantify free and conjugated steroids in fatty matrices by HPLC–MS/MS
(2020-05-22) Bezerra, Kelly da Silva; Antoniosi Filho, Nelson Roberto
Steroids are called the “fingerprint” of oils, fats, and their derivatives. Different classes of steroids may be present in these matrices. Most of the methods developed to analyze these constituents involve the determination of free steroid content, although their conjugated forms are extremely important in determining the total composition. Thus, this article demonstrates that the coupling of sequential mass spectrometry and high-performance liquid chromatography obtained high sensitivity and high specificity of mass resolution to identify and quantify the main classes of steroids. Four methods were developed to quantify steroids free, esterified, glucosides, and acylated glucosides by internal standardization using betulin. The main validation parameters were tested and demonstrated good correlation results for the methods. The content of free steroids was the majority in all samples, whereas the content of glucoside steroids was the least abundant. The contents of free steroids quantified in the degummed soybean oil were significantly reduced in relation to the refined oil. A small amount of esterified steroids was superior in refined soybean oil than in degummed oil. Comparing the steroid content between degummed oil and biodiesel, we found that the concentration of free and esterified steroids decreases in the conversion to biodiesel, whereas the concentration of glucoside steroids increases slightly.
Biosorption of hexavalent chromium by Pleurotus ostreatus
(2019) Ferreira, Glalber Luiz da Rocha; Vendruscolo, Francielo; Antoniosi Filho, Nelson Roberto
The existing techniques for the removal of heavy metals are expensive and
frequently inefficient. Thus the application of biosorbents has arisen as an
alternative, this being emergent technology that must be studied and explored,
with the aim of promoting better environmental and human life quality. The
objective of this study was to verify the capacity of active and inactive Pleurotus
ostreatus fungal biomass in removing Cr(VI) ions by biosorption from synthetic
aqueous solutions of these ions at concentrations of 10, 25, 50, 75, 100, 125 and
150 mg L -¹. When using active biomass, the kinetic studies showed that 100%
of biosorption was reached from the 25 mg L-¹
Cr(VI) solution in 360 hours,
equivalent to the removal of 169.84 mg g 1 of total Cr. On the other hand the
inactive biomass reached 100% of its saturation capacity in 22 minutes for a
concentration of 50 mg L-¹ of Cr(VI), equivalent to the removal of 368.21 mg
g 1 of total Cr. The kinetic study was shown to be highly effective, presenting
an efficiencies of times 500 and 750 for the active and inactive P. ostreatus
biomasses, respectively, when compared to the limit of 0.1 mg L-¹ of Cr(VI) for
industrial effluents described in CONAMA resolution n 430/2011.