Adelir Saczk

• Doctor of Philosophy in Chemistry
• Federal University of Lavras

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a polyphagous insect of various agricultural crops. The methods used for its control have led to the selection of resistant insect populations, which justifies the search for new alternatives for the management of this insect. Accordingly, in the present study, trypsin inhibitors...

In this study, a Cr2O3 catalyst was produced from a sulfochromic residue (SCR) generated in the analysis of soil organic matter. The Cr2O3 obtained from the residue was then characterized by techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (...

Electroplating sludge (ES) is a waste that is generated by the galvanization industry and is highly toxic because it contains heavy metals. This study examined the physiochemical properties of ES residue, the recovery of the present metals, and the reuse of these metals to add value to this residue and avoid environmental contamination through its...

p class="PaperAbstract"> In 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), an...

p>As atividades industriais geram resíduos de formas variadas que, predominantemente, apresentam um elevado grau de poluição, tendo, na maioria das vezes, os aterros industriais como disposição final. A indústria do couro é uma grande geradora de resíduos industriais, os quais apresentam volume residual da pele e de cromo, do couro curtido e do tra...

Both human and veterinary medicine have relied on the antibiotic sulfamethoxazole to treat infections. However, high consumption of this compound culminates in environmental and public health problems. In this context, here we describe a voltammetric method to determine sulfametoxazole levels, using a glassy carbon disc electrode, chemically modifi...

The HPLC technique with UV-Vis detection was employed in the analysis of cocaine content in apprehended samples of cocaine and crack. A peak signal for cocaine was obtained in 3.5 minutes run by using acetonitrile/water (95:5v/v) as a mobile phase. Optimized spectrophotometric signal was obtained at a wavelength of 224 nm. The analytical curve from...

A system based on batch injection analysis (BIA) associated with amperometric detection at screen-printed carbon electrode was used for the precise and rapid quantification of the anesthetics compounds benzocaine and tricaine in fresh fish fillets. Along this study, the best conditions for the BIA-amperometry system were stablished for the rapid de...

Blackberries are an important option for the diversification of fruit crops. However, there is currently no literature regarding plant cultivation in high-altitude tropical climates. Knowledge of the phenolic composition of blackberries is essential because variations in the levels of these components may exist between cultivars and may depend on e...

Conventional dispersive liquid-liquid microextraction (DLLME) and low density solvent-based dispersive liquid-liquid microextraction (LDS-DLLME) were evaluated in the extraction of menthol (1R, 2S, 5R)-2-isopropyl-5-methylcyclohexanol from tilapia (Oreochromis niloticus) fillets. The nature of the extraction and disperser solvents underwent univari...

O presente caso pretende apresentar um exemplo de gestão ambiental em Instituições de Ensino Superior (IES), destacando o Programa de Gerenciamento de Resíduos Químicos (PGRQ) da Universidade Federal de Lavras (UFLA). O caso será analisado pelas lentes teóricas da gestão ambiental, da sustentabilidade e da logística reversa - conceitos que em conju...

Yacon (Smallanthus sonchifolius) is a tuberous root from the Andean region in the South America rich em water, fructooligosaccharides and phenolic compounds, some of which are natural antioxidants and may help prevent the deleterious action of free radicals in the body. The yacon has attracted much attention due to their potential health benefits t...

The present study aims at evaluating the efficiency of the HZSM-5 zeolite dealuminated with citric acid and modified with sulfated lanthanum oxide (SO42−/La2O3) as catalysts for the production of biodiesel via esterification. The effects of the treatments in the structural, textural and acid properties of produced catalysts were monitored by PXRD,...

The waste generated in various academic activities is a major problem faced by universities. Thus the organic solvents residues have carcinogenic properties and if discarded improperly it will cause environmental impacts. This study aimed, treat and recover waste organic solvents (acetone, chloroform and ethyl ether) from different research and pra...

The 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 this work, a new and sensitive electroanalytical methodology was developed and validated to quantify sulfentrazone in soil samples. Sulfentrazone was initially characterized qualitatively using cyclic voltammetry (CV). Its oxidation occurred by diffusion (mass transport) on a glassy carbon electrode (GCE) via irreversible transfer of one electro...

The objective of this study was to adjust the kinetic data of the adsorption of residual copper(II) to the pseudo-first-order model, pseudo-second-order model, intraparticle diffusion and Elovich. The waste contained copper(II), generated in the analysis of protein determination at Departamento de Ciência dos Alimentos, of Universidade Federal de L...

Qualitative analytical chemistry course features the study of cations and anions, approaching identification and separation of these species. Cations are classified into groups and analyzed systematically, according to their similarities. Several analytical methods have been proposed for anion determination. However, a practical difficulty to analy...

In this study, use was made of tucumã cake, in natura (TCN) and thermally treated (TCT), as potential alternative adsorbents for the adsorption of cationic and anionic dyes. The effects of the parameters: contact time, adsorbent: adsorbate mass ratio, and initial concentration of dye were analyzed. The adsorption isotherms were established from opt...

Residual quantification of the anesthetics clove oil (CO) – isoeugenol (ISO), eugenol (EUG) and methyleugenol (MET) –,benzocaine (BZN) and tricaine (MS-222) was made in fillets of two fish species: Nile tilapia (Oreochromis niloticus) and acatfish hybrid, cachadia (Pseudoplatystoma reticulatum x Leiarius marmoratus). Samples (n=4) of each fish were...

There are residual organic and inorganic contaminants in the cachaça production chain. Among the organic contaminants, ethyl carbamate has been widely studied. It is formed naturally during the fermentation processes and can be found in many foods and beverages such as bread, yoghurt, wine, beer and especially in fermented–distilled beverages such...

Fall armyworm, Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae) is the main pest of maize, besides attacking sorghum and cotton crops. The control of this pest has been accomplished mainly with the use of synthetic insecticides but, due to the growing concern about the environment and food quality, phenolic compounds have shown their...

Procymidone, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to apple crops. In this work, we propose a reliable and sensitive method to determine procymidone in Brazilian apples. The method involves differential pulse (DPV) and square-wave voltammetry (SWV) techniques on a gl...

Sugar is widely consumed worldwide and Brazil is the largest producer, consumer, and exporter of this product. To guarantee proper development and productivity of sugar cane crops, it is necessary to apply large quantities of agrochemicals, especially herbicides and pesticides. The herbicide tebuthiuron (TBH) prevents pre- and post-emergence of inf...

A simple procedure for recovering potassium dichromate (K 2Cr2O7) from treatment of residual sulphochromic solution was proposed in the present work by means of cooling crystallization. The decrease of temperature favored the crystallization of K2Cr2O7 due to the decrease of solubility. 5.0 L of sulphochromic wastes containing 48.08 g L-1 of Cr(VI)...

This work investigated the effects of temperature and of rate of heating on the kinetic parameters of pyrolysis of castor beans presscake, a by-product generated in the biodiesel production process. Pyrolysis process was investigated by thermogravimetric analysis and parameters were obtained from non-isothermal experiments. The results obtained fro...

A utilização de bicombustíveis, principalmente em veículos motoriza-dos, constitui atualmente uma alternativa de grande viabilidade em diver-sas matrizes energéticas de vários países. Desta forma, o bioetanol, etanol derivado da biomassa, destaca-se pela possibilidade de ser utilizado como combustível propriamente dito (hidratado) e também como adi...

In this work the use of the heterogeneous catalysts pure (LO) and sulfated (SLO) lanthanum oxide, pure HZSM-5 and SLO/HZSM-5 (HZSM-5 impregnated with sulfated lanthanum oxide (SO(4)(2-)/La(2)O(3))) was evaluated. The structural characterization of the materials (BET) showed that the sulfation process led to a reduction of the SLO and SLO/HZSM-5 sur...

Determination of organic acids in soils and organic materials is important due to the important role they play in improving the soil's physical, chemical and microbiological conditions. This study identified and quantified low molecular weight organic acids (LMWOA) in soils (dystroferric Red Latosol, dystrophic Red-Yellow Latosol and Quartzarenic N...

The development of an electroanalytical method for simultaneous determination of copper and lead ions in sugar cane spirit (cachaça) using carbon paste electrode modified with ascorbic acid and carbon nanotubes (CPE-AaCNT) is described. Squarewave voltammetry (SWV) with anodic stripping was employed, and this technique was optimized with respect to...

Brazil An eletroanalytical method for determination of arsenic in sugar cane brandy using an electrode consisting of carbon paste modified with carbon nanotubes (CNTPE) and mineral oil has been developed. The cyclic (CV) and linear sweep voltammetry modes (LSV) with cathodic stripping were employed for CNTPE containing mineral oil. The analytical c...

This work has been carried out in order to determine the copper content in sugar cane spirit samples from the south of Minas Gerais, using a carbon paste electrode modified with ascorbic acid and carbon nanotubes using the square wave voltammetry technique. The following parameters were studied: Ed (deposit potencial). Td (deposit time), f (frequen...

A new voltammetric method for the determination of Δ(9)-tetrahydrocannabinol (Δ(9)-THC) is described. The voltammetric experiments were accomplished in N-N dimethylformamide/water (9:1, v/v), using tetrabutylammonium tetrafluoroborate (TBATFB) 0.1mol/L as supporting electrolyte and a glassy carbon disk electrode as the working electrode. The anodic...

A comparative study between three automotive headlights (conventional, halogen, and HID lamp) using scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) is described. Results show the possibility of conducting topographic and qualitative analysis of automotive light bulbs from vehicles involved in traffic accidents on...

The potential of natural and heat-treated Macauba palm cake as adsorbent for the removal of Methylene Blue (MB) and Congo Red (CR) from solution has been investigated. Equilibrium adsorption was attained in <7 h and the process was favored at pH 5.0 for MB and pH 6.5 for CR with an adsorbent (g):adsorbate (mL) ratio of 1:200 and an initial concentr...

Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) techni...

A chromatographic methodology for Δ9-THC analysis in cosmetics is described. The HPLC-UV-Vis technique was employed for quantification of Δ9-THC in the 1.0 to 100 ppm working range using an optimized mobile phase consisting of methanol/water (4:1). In these experimental conditions, Δ9-THC presented a retention time of 23.7 minutes at the optimized...

The presence of contaminants, such as phosphate, in biodiesel, has several drawbacks for instance: current engines perform poorly, fuel tanks deteriorate, catalytic conversion is damaged, and particles emission is increased. Therefore, biodiesel quality control is extremely important for biodiesel acceptance and commercialization worldwide. In this...

Different solvents were evaluated for the extraction of jabuticaba anthocyanin pigments, identifying, quantifying and verifying the stability of the anthocyanins, as well as the conduction of three antioxidant activity assays and determination of the vitamin C levels. The maceration with ethanol acidified with HCl 1.5 mol L-1 (85:15) provides bette...

The identities and quantities of the phenolic compounds and coumarins in twelve samples of sugar cane spirit aged in Quercus sp., Amburana cearensis, Cariniana legalis, Castanea sativa Mill, Ocotea sp., Cotyledon orbiculata L., and Hymenaea sp. casks were determined. These compounds have a direct influence on the sensory characteristics of aged bev...

Cachaça is a traditional and popular Brazilian drink obtained by distilling fermented sugar cane juice. Among the steps involved in its production, natural aging in wood containers for a certain period of time can lead to alterations in the chemical composition, aroma, flavor and color of the beverage. The present work sought to determine the conce...

A low-cost electrochemical method was developed for the determination of trace-level of methyl parathion (MP) based on the properties of graphite-modified basal plane pyrolytic graphite electrode (graphite-bppg). A combination of graphite-bppg with square-wave voltammetric (SWV) analysis resulted in an original, sensitive and selective electrochemi...

Recebido em 30/7/10; aceito em 16/11/10; publicado na web em 25/2/11 IDENTIFICATION OF ETHYL CARBAMATE DURING THE AGING OF CACHAÇA IN AN OAK BARREL (Quercus sp) AND A GLASS VESSEL. The objective of the present study was the identification and quantification of ethyl carbamate (EC), by HPLC-FLD, after different periods of storage in an oak (Quercus...

The objective of the present study was the identification and quantification of ethyl carbamate (EC), by HPLC-FLD, after different periods of storage in an oak (Quercus sp) barrel and a glass vessel. The concentration of EC in the cachaça samples varied from <LD to 17.46 µg L-1, for the period during which the cachaça was stored in an oak barrel, a...

The objective of the present study was the evaluation of the presence of organic and inorganic contaminants in samples of aged cachaça from the South of the state of Minas Gerais. Furfural, methanol and copper were determined by colorimetric reactions, while the analyses of ethyl carbamate and acrolein were performed by GC/MS and HPLC, respectively...

The existence of organic and inorganic contaminants present in both fossil and biomass fuels and the fact that they can provide undesirable effects (environmental problems, corrosion processes, lead to storage instability, and others) implies a rigorous quality control of these fuels, although these contaminants make up a small part of the final fu...

A técnica de CLAE com detecção UV-Vis foi empregada na análise do teor de cocaína em amostras apreendidas de cocaína e crack. Uma fase móvel de acetonitrila/água (95:5v/v) possibilitou um sinal de pico para a cocaína em 3,5 minutos. O sinal espectrofotométrico otimizado foi obtido em um comprimento de onda de 224 nm. A curva analítica de 1,0 a 40,0...

A fast and accurate method is proposed to determine the presence of copper, iron, nickel, and zinc in fuel ethanol. Aqueous stock solutions of iron, zinc, nickel, and copper by diluting standard solution of each metal in deioinzed water are used for this study. The commercial samples of fuel ethanol for the study are collected from different gas st...

A high performance liquid chromatography (HPLC) method with electrochemical detection (ED) was developed for the determination of benzidine, 3,3‐dimethylbenzidine, o‐toluidine and 3,3‐dichlorobenzidine in the wastewater of the textile industry. The aromatic amines were eluted on a reversed phase column Shimadzu Shimpack C18 using acetonitrile+ammon...

The voltammetric reduction of acetaldehyde was studied in 0.1 M LiOH: LiCl (60: 40 v/v). Well-defined waves can be seen at −1.77 and −1.60 V with the use of hanging mercury and glassy carbon electrodes. Acetaldehyde was shown to react at room temperature with the 2,4-dinitrophenylhydrazine and the product exhibited a differential pulse voltammetri...

A new methodology was developed for analysis of aldehydes and ketones in fuel ethanol by high-performance liquid chromatography (HPLC) coupled to electrochemical detection. The electrochemical oxidation of 5-hydroxymethylfurfural, 2-furfuraldehyde, butyraldehyde, acetone and methyl ethyl ketone derivatized with 2,4-dinitrophenylhydrazine (DNPH) at...

A high-performance liquid chromatography (HPLC) method for the determination of acetaldehyde in fuel ethanol was developed. Acetaldehyde was derivatized with 0.900 mL 2,4-dinitrophenylhydrazine (DNPHi) reagent and 50 microL phosphoric acid 1 mol L(-1) at a controlled room temperature of 15 degrees C for 20 min. The separation of acetaldehyde-DNPH (...

The cyclic voltammetric behavior of acetaldehyde and the derivatized product with 2,4-dinitrophenylhydrazine (DNPHi) has been studied at a glassy carbon electrode. This study was used to optimize the best experimental conditions for its determination by high-performance liquid chromatographic (HPLC) separation coupled with electrochemical detection...

A new, versatile, and simple method for quantitative analysis of zinc, copper, lead, and cadmium in fuel ethanol by anodic stripping voltammetry is described. These metals can be quantified by direct dissolution of fuel ethanol in water and subsequent voltammetric measurement after the accumulation step. A maximum limit of 20% ( v/ v) ethanol in wa...

The model compounds for horseradish peroxidase (HRP) is reported, based on the association of H2O2 with iron and manganese porphyrins immobilized onto a functionalized silica gel. The models were developed in an attempt to find a biomimetical compound for systems containing heme groups. The ortho-dianisidine is a useful substrate model compound for...

A flow-injection system with a glassy carbon disk electrode modified with Prussian Blue film is proposed for the determination of persulfate in commercial samples of hair bleaching boosters by amperometry. The detection was obtained by chronoamperometric technique and the sample is injected into the electrochemical cell in a wall jet configuration....

Estudos eletroanalíticos foram realizados com o Nedocromil de Sódio empregando as técnicas voltamétricas de varredura linear, pulso diferencial e onda quadrada, em tampão Britton-Robinson (pH 4,0). No estudo voltamétrico empregando a modalidade de varredura linear observou-se dois picos catódicos, irreversíveis, nos valores de potencial de -0,86 V...

Electroanalytical studies had been carried with the Nedocromil Sodium, an antiasthmatic drug, using the techniques of Linear Scan, Diferencial-Pulse and Square Wave Voltammetry. The technique of Linear Scan Voltammetry was used for determination of Nedocromil Sodium, at a glassy carbon electrode, in pH 4 Britton-Robinson buffer. Two irreversible re...

The presence of heavy metals in fuel ethanol is obtained in different steps as production and storage of ethanol, constituting an inorganic contamination. Quantitative analysis of these contaminants has been usually carried out by conventional techniques as atomic absorption spectrofotometry, According to high sensibility of stripping voltammetric...

This study reports the electrochemical behavior of 2-furfuraldehide reduction in ethanol using glassy carbon electrode, aiming to correlate adequate experimental conditions for determination of this 2-furfuraldehide in fuel ethanol. Obtained voltammograms for 2-furfuraldehide in a scan rate of 100 mV.s(-1) present a cathodic peak current in a poten...

Este estudo descreve o comportamento voltamétrico da redução de 2-furfuraldeído em etanol utilizando-se eletrodo de carbono vítreo, visando estabelecer condições experimentais adequadas para a determinação de 2-furfuraldeído em álcool combustível. Os voltamogramas obtidos para o 2-furfuraldeído em uma velocidade de varredura (v) de 100mV.s-1 aprese...

A presença de metais pesados em álcool combustível origina-se na produção e armazenamento do álcool etílico, constituindo uma contaminação inorgânica. A análise quantitativa deste contaminante tem sido usualmente monitorada empregando-se técnicas convencionais de análise tal como espectrofotometria de absorção atômica. Tendo em vista a alta sensibi...