Abstract The chemical composition of volatile compounds from Spondias tuberosa fruits were investigated at four days of maturity and from two accessions. These days were characterized through the compounds’ profiles obtained by extracting volatiles using solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). A total of 27 and 22 compounds were identified from the EPAMIG-C02 and EPAMIG-C10 accessions, respectively. The main chemical class in both accessions were the esters, aldehyde, alcohols and terpenes. The study revealed a tendency to increase the ester content and decrease the aldehyde and terpene content during four days of post-harvest ripening for the two accessions. This behavior may be monitored by five key compounds such as two esters (ethyl butanoate and ethyl hexanoate) and three aldehydes (hex-2-enal, nonanal and dec-2-enal). These compounds may be used as markers for the maturity stage for the two accessions. The Principal Components Analysis (PCA) accumulated 73.85% of the total variance in principal components 1 and 2 and showed that it is possible to differentiate the fruit ripening stages through these compounds.

Resumo Apesar da alta importância social da Spondias tuberosa Arruda, têm sido raros os estudos sobre as substâncias voláteis de frutos do umbuzeiro conhecido como umbu. Por isso, o objetivo deste estudo foi determinar as melhores condições de extração destas substâncias por microextração em fase-sólida no modo headspace (MEFS-HS) para caracterizar o perfil de voláteis na polpa dos frutos de umbu por cromatografia gasosa acoplada à espectrometria de massas (CC-EM). As condições ótimas de extração foram obtidas usando 4 g da polpa da fruta e 0,2 NaCl/polpa (m/m), mantidos por 10 min em incubação a 40 °C. A fibra de MEFS foi exposta por 20 min para a extração dos compostos e, em seguida, por 40 min para dessorção no injetor do cromatógrafo. Nestas condições, um total de 25 substâncias voláteis foram detectadas, sendo 11 delas identificadas pela primeira vez na fração volátil de polpa de umbu e 3 compostos pela primeira vez no gênero Spondias. As principais classes químicas foram os terpenos e os ésteres, os quais, juntos, representam mais de 90 % da área cromatográfica total.

Abstract despite the high social and economic importance of Spondias tuberosa Arruda, to the best of our knowledge there are very few detailed studies on the volatile compounds of this fruit popularly named umbu. Therefore, the aim of this study was to find the best extraction conditions by solid-phase microextraction in headspace mode (HS-SPME) to determine the volatile compounds from umbu fruit pulp by gas-chromatography coupled to mass spectrometry (GC-MS). The optimal conditions were obtained using 4 g of pulp and 0.2 NaCl/pulp (w/w), maintained for 10 min in incubation at 40 °C. The SPME-fiber was exposed for 20 min for extraction and then for 40 min for desorption. Thus, a total of 25 volatile compounds were detected and 16 were identified under these conditions, with 9 compounds being identified for the first time in the volatile fraction of umbu fruit pulp and two compounds were identified for the first time in the Spondias genus. The major chemical class was terpenes and esters, which together represent more than 90% of total chromatographic area.

Abstract In this study, the volatile organic compounds from Spondias tuberosa fruits of 16 accessions with different origins were extracted by solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). The volatile compounds present in the fruit from the 16 accessions were identified and submitted to multivariate analysis, with the main volatile compounds identified (from a total of 25) being: ethyl butanoate, α-pinene, myrcene/ethyl caproate, limonene, ocimene isomers, linalool/nonanal and p-menth-1-en-4-ol. The major chemical classes were terpenes (about 7-72%) and esters (about 14-72%). The relative chromatographic areas of the volatile compounds were used in Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), which accumulated 67.69% of the explained variance. The compounds classified as esters and terpenes were the main compounds responsible for forming distinct groups. The PC1 and PC2 enabled distinguishing the percentage of compounds responsible for grouping in the PCA quadrants and the HCA shows the grouping of these compounds.

Resumo Na bananicultura, o uso de sacos impregnados por inseticida e a lavagem das pencas são técnicas que visam à qualidade dos frutos. Objetivou-se monitorar, por cromatografia em fase gasosa acoplada à espectrometria de massas, resíduo de bifentrina em bananas lavadas e não lavadas em tanques, assim como na água de lavagem dos frutos. Desde a emissão até a colheita, os cachos foram protegidos com sacos impregnados por bifentrina a 1,0 g kg-1, os quais foram retirados após a colheita, para despencamento e lavagem ou não das pencas em tanques com água, detergente e sulfato de alumínio. Os métodos Quick, Easy, Cheap, Effective, Rugged, Safe Method - QuEChERS e Extração Líquido – Líquido com Partição a Baixa Temperatura - ELL – PBT foram utilizados para extrair resíduo de bifentrina dos frutos no ponto de colheita e maduros, e da água, respectivamente. As porcentagens de recuperação de bifentrina foram 88,16%, 103,4% e 89,32%, na casca, na polpa e em casca + polpa, respectivamente, atendendo à legislação brasileira. No ponto de colheita, na casca e na casca + polpa dos frutos lavados, detectou-se 0,060 mg kg-1 e 0,010 mg kg-1, respectivamente. Quando não lavados, a concentração de bifentrina, na casca, foi de 0,31 mg kg-1 e de 0,16 mg kg-1, na casca + polpa. Não foi detectado resíduo de bifentrina na polpa, independente do estádio de maturação e lavagem, tampouco na água de lavagem. Em frutos maduros não lavados, foram quantificado 0,10 mg kg-1 e 0,040 mg kg1 de bifentrina na casca e em casca + polpa, respectivamente. A lavagem não elimina, mas reduz o resíduo de bifentrina na casca dos frutos no ponto de colheita e, quando maduros, somente os não lavados apresentam resíduo.

Abstract In banana farming, the use of bags impregnated by insecticides and the washing of bunches are techniques that aim at maintaining the quality of fruits. This study aimed to monitor, by Gas Chromatography (GC) coupled with Mass Spectrometry (MS), bifenthrin residue in washed and unwashed bananas, as well as in the fruit washing water. From the emission until the harvest, the bunches were protected with bags impregnated with bifenthrin at 1.0 g kg-1, which were removed after harvest for fruit dropping and washing or not bunches in tanks with water, detergent and aluminum sulfate. The Quick, Easy, Cheap, Effective, Rugged, Safe Method - QuEChERS and liquid-liquid extraction with the low temperature partition method were used to extract bifenthrin residue from fruits at harvest point and ripe, and from water, respectively. Bifenthrin recovery percentages were 88.16%, 103.4% and 89.32% in peel, pulp and in peel + pulp, respectively, in compliance with Brazilian legislation. At the harvest point, 0.060 mg kg-1 and 0.010 mg kg-1 were detected in peel and in peel + pulp of washed fruits, respectively. When unwashed, bifenthrin concentration in peel was 0.31 mg kg-1 and 0.16 mg kg-1 in peel + pulp. No bifenthrin residue was detected in pulp, regardless of maturation stage and washing, as well as in the washing water. In mature unwashed fruits, 0.10 mg kg-1 and 0.040 mg kg-1 of bifenthrin were detected in peel and in peel + pulp, respectively. Washing does not eliminate the residues, but reduces bifenthrin residue in fruit peel at the harvest point; when ripe, only unwashed fruits showed presence of bifenthrin residue.

RESUMO Catharanthus roseus (L.) G. Don é uma planta medicinal conhecida por importantes compostos aromáticos constituintes. Na literatura, não há estudos detalhados que elucidem os métodos de extração de compostos fenólicos para esta espécie. Portanto, o presente estudo teve como objetivo avaliar os parâmetros de maceração para determinar a concentração de fenóis totais em C. roseus. Os parâmetros de massa de planta, composição da fase extratora, tipo de homogeneização, tempo de extração e temperatura foram avaliados para melhorar as condições de extração. Os extratos das plantas foram submetidos à análise espectrofotométrica para cada parâmetro e a concentração de fenóis totais foi determinada. Após estabelecer condições ótimas, os extratos foram preparados a partir de cultivares de C. roseus, seguidos da avaliação da atividade antioxidante por espectrofotometria, conteúdo de ácidos fenólicos por CG-EM e dissimilaridade pelo método de pares de médias aritméticas não ponderadas. As condições ótimas de extração obtidas foram: 30 mg de tecido vegetal seco em 0.72 mL de fase de extração etanol: água, 50:50 (v/v), a 50 ºC por 1 h. A concentração média de fenóis totais foi de 30.3 mg g-1 equivalentes de ácido gálico (EAG) e 20.0 mg g-1 equivalentes de quercetina (EQ) para flavonoides. A atividade antioxidante determinada pelos métodos DPPH, ABTS e FRAP foi de 19.4, 11.8 e 23.3 mg g-1 de concentração equivalente de Trolox e atividade antioxidante (CETAA), respectivamente. Houve predomínio de ácidos ferúlico (42%-56%) e cafeico (21%- 52%) nos extratos de folhas de C. roseus. O processo de extração aumentou o teor de fenóis totais em 55%, de 18 para 28 mg EAG.

ABSTRACT Catharanthus roseus(L.) G. Don is a medicinal plant known for its important constituent aromatic compounds. In the literature, no detailed studies elucidating the methods of extraction of phenolic compounds for this species are available. Therefore, the present study was aimed at evaluating the maceration parameters for determining the total phenols content in C. roseus. The parameters of plant mass, extraction phase composition, homogenization type, extraction time, and temperature were evaluated in terms of improving the extraction conditions. The plant extracts were subjected to specific spectrophotometric analysis designed for each parameter, and the total phenols content was determined. After establishing the optimal conditions, the extracts were prepared from C. roseus cultivars, followed by evaluation of antioxidant activity using spectrophotometry, phenolic acid content using GC-MS, and dissimilarity using Unweighted Pair Group Method in combination with the Arithmetic Mean method. The optimal extraction conditions obtained were: 30 mg of dry plant tissue in 0.72 mL of extraction phase ethanol:water, 50:50 (v/v) at 50 °C for 1 h. The average total phenols content was 30.3 mg g-1 of gallic acid equivalents (GAE) and 20.0 mg g-1 of flavonoid quercetin equivalents (QE). The antioxidant activities determined using the DPPH, ABTS, and FRAP methods were 19.4, 11.8, and 23.3 mg g-1 of Trolox equivalent antioxidant capacity (TEAC), respectively. There was a predominance of ferulic (42%-56%) and caffeic (21%-52%) acids in the leaf extracts of C. roseus. The extraction process increased the total phenol content by 55%, from 18 to 28 mg GAE.

Abstract In banana farming, the bagging of bunches with bags impregnated by pyrethroid insecticide is a practice that prevents damage to fruits caused by insect pests. The aim of this study was to monitor the presence and permanence of bifenthrin residue during the maturation of ‘Grande Naine’ banana by gas chromatography coupled to mass spectrometer in the selective ion mode (GC-MS-SIM). Fruits were from bagged and non-bagged bunches and the extraction of bifenthrin residue from peel and pulp was performed with QuEChERS and LSE-LTP (Liquid-Solid Extraction - Low Temperature Partitioning) methods. The maturation stages were characterized as 1; 3 and 7 depending on the fruit peel color. The bifenthrin recovery percentages in banana peel and pulp obtained by QuEChERS and LSE-LTP methods are between 97% and 117%, and therefore, within the criteria of acceptability for residues of agrochemicals according to the Brazilian legislation and vary according to the matrix. The mean bifenthrin concentrations in the peel of fruits from bagged bunches were 0.34 mg kg -1, 0.29 mg kg -1 and 0.10 mg kg -1 at stage 1 (harvest point); 3 and 7, respectively. No bifenthrin residue was detected in fruit pulp at any maturation stage.

In this study, a method of solid-liquid extraction and purification at low temperature (SLE-PLT) to determine 16 polycyclic aromatic hydrocarbons (PAHs) in sewage sludge was optimized and validated. The analyses were performed by HPLC-UV. The extraction phase, homogenization procedure, influence of pH, ionic strength and clean-up of the extracts were optimized. Recoveries were higher than 63.4% for 11 PAHs. The correlation coefficients were greater than 0.99 and limits of detection and quantitation were less than 0.060 and 0.15 µg g-1, respectively. These values were lower than the maximum residue limits of PAHs established by European legislation. SLE-PLT proved a more practical, economical method with fewer steps compared to Soxhlet extraction (reference method) for PAHs in sewage sludge.

This study optimized and validated the liquid-liquid extraction technique with partition at low temperature (LLE-PLT) for identification and quantification of four pesticides (chlorpyrifos, λ-cyhalothrin, permethrin, bifenthrin) in water samples. Analyses were performed by HPLC-UV. The technique was efficient for pesticide recovery with extraction exceeding 86%. Chromatographic response was linear for the four compounds in the 10-45 µg L-1 range, with correlation coefficients greater than 0.99. Limits of detection and quantitation were less than 3.5 µg L-1 and equal to 10 µg L-1, respectively. The proposed method was applied to 29 water samples from the Jaíba Project in northern Minas Gerais.

Components in complex matrices can cause variations in chromatographic response during analysis of pesticides by gas chromatography. These variations are related to the competition between analytes and matrix components for adsorption sites in the chromatographic system. The capacity of the pesticides chlorpyrifos and deltamethrin to be adsorbed in the injector and chromatographic column was evaluated by constructing three isotherms and changing the column heating rate to 10 and 30 ºC min-1. By using ANCOVA to compare the slope of calibration graphs, results showed that the higher the injector temperature (310 ºC) the lower the pesticide adsorption. Also, deltamethrin influenced the adsorption of chlorpyrifos on the column chromatographic.

Multiresidue methods for pesticides monitoring by GC are commonly employed, however, it is well known that the presence of compounds of the matrix introduces errors during the quantiûcation. The main consequence of matrix effect is an increasing or decreasing analyte signal after the GC saturation with extracts of matrix. In this paper, the influence of constituents of nine matrices on the quantification of the four pesticides by GC-ECD was studied. Variation of signal was evaluated by PCA and HCA, and results showed that the constituents of tomato increased the signal (until 300%), while extracts of apple decreased (until -20%). Variation the analyte signal in the presence of the matrix in respect to the same analyte in solvent (standard solution) also was observed, mainly for liver extract (until 270%).

In this paper historical aspects of analytical pyrolysis, the equipment used, the fundamentals and the mechanisms of pyrolysis of different polymeric materials are discussed. The latest work on analytical pyrolysis applied to various types of synthetic and natural samples is reviewed. Current applications of this technique that are discussed include identification of microorganisms, analysis of trace compounds by forensic laboratories, investigation of food and agricultural products, study of the chemical composition of wood, authentication and conservation of artworks, and the study of environmental and geochemical samples.

Neste trabalho foi avaliado o teor de extrativos em madeiras de eucalipto, por meio de extrações com acetona, mistura de tolueno:etanol (2:1), clorofórmio e diclorometano. As maiores porcentagens de extrativos totais foram obtidas ao utilizar acetona como solvente. Os extratos obtidos em acetona e tolueno:etanol foram ressuspendidos em diclorometano, para avaliação do teor de extrativos lipofílicos. As porcentagens desses extrativos foram semelhantes às obtidas com diclorometano ou clorofórmio, em extrações diretas. Os extratos foram analisados por espectroscopia no infravermelho, para identificação dos principais grupos funcionais dos constituintes extraídos.

The extractives content in eucalypt woods were evaluated using direct extractions with acetone, mixture of toluene:ethanol (2:1), chloroform and dichloromethane. The largest percentages of extractives were obtained using acetone as solvent. The extracts obtained in acetone and toluene:ethanol were dissolved in dichloromethane to establish the percentage of lipophilic extractives. The percentages of these extractives were similar to those obtained with dichloromethane or chloroform by direct extractions. The extracts were analyzed by infrared spectroscopy to identify the main functional groups.