Navegando por Autor "Saczk, Adelir A."
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Item Analysis of sulfamethoxazole by square wave voltammetry using new carbon paste electrode(Journal of Electrochemical Science and Engineering, 2018) Okumura, Leonardo L.; Eleotério, Izabel C.; Balbino, Marco A.; Andrade, José F. de; Ferreira, Bruno; Saczk, Adelir A.; Batista, Antonio Carlos F.; Oliveira, Marcelo F. deIn this work a new model of carbon paste electrode was employed to determine sulfamethoxazole (SMX), an antibiotic used to treat infections in human and veterinary medicine, by the square wave voltammetric modality (SWV). More specifically, the electrochemical behavior of SMX was investigated by cyclic voltammetry (CV), and the quantitative analysis of SMX was provided by SWV. The analytical curve was obtained with a linear correlation coefficient (r) of 0.985 and standard deviation (SD) of 0.005 μA. Limits of detection and quantification were found as 2.3×10 -6 and 7.7×10 -6 mol L -1 , respectively. According to the obtained results, the new carbon paste prototype electrode can successfully be employed in this kind of electroanalytical applications.Item Cathodic stripping voltammetric determination of arsenic in sugarcane brandy at a modified carbon nanotube paste electrode(Food Chemistry, 2014-01-05) Teixeira, Meryene C.; Tavares, Elisângela de F.L.; Saczk, Adelir A.; Okumura, Leonardo L.; Cardoso, Maria das Graças; Magriotis, Zuy M.; Oliveira, Marcelo F. deWe have developed an eletroanalytical method that employs Cu2+ solutions to determine arsenic in sugarcane brandy using an electrode consisting of carbon paste modified with carbon nanotubes (CNTPE) and polymeric resins. We used linear sweep (LSV) and differential-pulse (DPV) voltammetry with cathodic stripping for CNTPE containing mineral oil or silicone as binder. The analytical curves were linear from 30 to 110 μg L−1 and from 10 to 110 μg L−1 for LSV and DPV, respectively. The limits of detection (L.O.D.) and quantification (L.O.Q.) of CNTPE were 10.3 and 34.5 μg L−1 for mineral oil and 3.4 and 11.2 μg L−1 for silicone. We applied this method to determine arsenic in five commercial sugarcane brandy samples. The results agreed well with those obtained by hydride generation combined with atomic absorption spectrometry (HG AAS).Item Forensic investigation of formaldehyde in illicit products for hair treatment by dad‐hplc: a case study(Journal of Forensic Sciences, 2016-02-29) Okumura, Leonardo L.; Oiye, Erica N.; Ribeiro, Maria Fernanda M.; Saczk, Adelir A.; Ciancaglini, Pietro; Oliveira, Marcelo F. deThe illegal use of formalin (commercial formaldehyde) in cosmetic products harms the health of individuals exposed to this substance. Over the last years, the commercial availability of these products, especially those containing irregular dosage of formaldehyde, has increased in Brazil. This work analyzes some products for hair treatment available in the Brazilian market and verifies their safety. The adopted analytical methodology involved sample derivatization with 2,4‐dinitrophenylhydrazine, followed by high‐performance liquid chromatography with ultraviolet detection (UV–VIS) at λ = 365 nm. The limit of quantification is 2.5 × 10−3% w/w, and the recovery tests were around 93%. Some of the samples contained high and illegal formaldehyde levels ranging from 9% to 19% (w/w) and others presented suitable concentrations of the analyte. On the basis of the results, this work discusses the efficiency and practicality of this analytical method for forensic purposes.