Caracterização de cereja-do-rio grande (Eugenia involucrata DC. ) e grumixama (Eugenia brasiliensis LAM. ), frutos nativos da Mata Atlântica, quanto a compostos voláteis e precursores / Volatile compounds and precursors characterization of the Grumixama (Eugenia brasiliensis LAM. ) and Cereja-do-Rio-Grande (Eugenia involucrata DC. ), atlantic forest native fruits

Mesmo reduzida e fragmentada, o vasto bioma da Mata Atlântica abriga milhares de plantas. Como destaque, tem-se as espécies frutíferas, aos quais podem ser atribuídas um importante valor para a segurança alimentar, nutricional e sociocultural. Entre elas, têm-se a cereja-do-rio grande (Eugenia involucrata DC.) e a grumixama (Eugenia brasiliensis Lam.), caracterizadas pela polpa de sabor doce-acidulado, sendo muito apreciadas e utilizadas tanto in natura, quanto no preparo de doces, xaropes, licores e geleias. Uma das características determinantes para o sucesso e aceitação destes frutos pelo consumidor, são os atributos de qualidade sensorial. As propriedades aromáticas dos frutos dependem da potência individual dos voláteis e a concentração de cada um, bem como a combinação com outros compostos. Todavia, apesar do grande potencial de mercado, devido às características nutricionais, fitoterápicas, potencial funcional e ao sabor exótico, os plantios existentes destas são oriundos de multiplicação por sementes, resultando em plantas desuniformes quanto as características de produção e qualidade. Neste sentido, o presente trabalho teve como objetivo identificar metabólitos voláteis que confiram características sensoriais desejáveis aos frutos. Auxiliando na identificação de plantas que produzem frutos com voláteis de interesse para o sabor, o que permitirá a clonagem e propagação de plantas com homogeneidade na produção. Os compostos voláteis foram analisados em triplicata, de acordo com o método de microextração em fase sólida (SPME, do inglês Solid Phase Microextraction). Os resultados mostraram que os grupos de frutos das diversas regiões se diferenciaram quanto a composição dos metabolitos voláteis, bem como na abundância destes compostos. Observou-se também uma variação de composição entre as árvores da mesma região demonstrando tal irregularidade ocasionada pela propagação por sementes. A maioria de compostos voláteis produzidos foram identificados como terpenos, sendo estes já conhecidos pela importância no flavor em frutos. Desta forma, conhecer o aroma fornecerá um conjunto de dados que são subsídios para outros pesquisadores trabalharem em suas diversas áreas buscando características necessárias para o sucesso da comercialização, ocasionando no incentivo ao cultivo e valorização da riqueza nacional, no âmbito das espécies frutíferas, com vistas à proteção ambiental e em defesa da biodiversidade brasileira

The Atlantic Forest harbors thousands of plants despite of its reduced and fragmented character. It is important to highlight the fruit species which hold attributed and important value for food and socio-cultural security. Among them, there are the big cherry (Eugenia involucrata DC.) And the grumixama (Eugenia brasiliensis Lam.), fruit with sweet-acidulated flavor, which is much appreciated and used in the preparation of sweets, syrups, liqueurs, and jellies. One of the determining characteristics for the success and acceptance of these fruits by the consumer are the attributes of sensorial quality. The aromatic properties of the fruits depend on the individual potency of the volatiles and the concentration in each one of them, as well as the combination with other compounds. Despite of the great market potential due to the nutritional, phytotherapic and exotic flavor characteristics, the existing plantations of these fruits are originated from seed multiplication, resulting on uneven plants in terms of production and quality characteristics. In this sense, the presented work below was aimed to identify volatile metabolites that confer desirable sensorial characteristics to the fruits. The volatile compounds were analyzed in triplicate according to the Solid Phase Microextraction (SPME) method. The results showed that the fruit groups from different regions differed in terms of the composition of volatile metabolites, as well as in the abundance of these compounds. There was also a variation of composition among the trees of the same region which demonstrated such heterogeneity caused by seed propagation. Most volatile compounds produced were identified as terpenes which are known for playing an important role in the flavor of fruits. In this way, by knowing the aroma, a set of data will be provided and used as an allowance for other researchers who are working in the various areas related to the pursue of the necessary characteristics for the commercial success, resulting on the motivation to cultivate and value the forest

High-speed identification of odor changes and substance basis of Myristicae Semen mildew by electronic nose and HS-GC-MS / 中国中药杂志

This study adopted headspace-gas chromatography-mass spectrometry(HS-GC-MS) and electronic nose to detect volatile components from Myristicae Semen samples with varying degrees of mildew, aiming at rapidly identifying odor changes and substance basis of Myristicae Semen mildew. The experimental data were analyzed by electronic nose and principal component analysis(PCA). The results showed that Myristicae Semen samples were divided into the following three categories by electronic nose and PCA: mildew-free samples, slightly mildewy samples, and mildewy samples. Myristicae Semen samples with different degrees of mildew greatly varied in volatile components. The volatile components in the samples were qualitatively and quantitatively detected by HS-GC-MS, and 59 compounds were obtained. There were significant differences in the composition and content in Myristicae Semen samples with different degrees of mildew. The PCA results were the same as those by electronic nose. Among them, 3-crene, D-limonene, and other terpenes were important indicators for the identification of mildew. Bicyclo[3.1.0]hexane, 4-methylene-1-(1-methylethyl)-, terpinen-4-ol, and other alcohols were key substances to distinguish the degree of mildew. In the later stage of mildew, Myristicae Semen produced a small amount of hydroxyl and aldehyde compounds such as acetaldehyde, 2-methyl-propionaldehyde, 2-methyl-butyraldehyde, and formic acid, which were deduced as the material basis of the mildew. The results are expected to provide a basis for the rapid identification of Myristicae Semen with different degrees of mildew, odor changes, and the substance basis of mildew.

Anti-leishmanial activity and identification of chemical constituents of Scrophularia striata essential oil by head space solid phase micro extraction gas chromatography mass spectrometry (HS-SPME GC-MS) / Actividad anti-leishmanial e identificación de componentes químicos del aceite esencial de Scrophularia striata mediante microextracción en fase sólida en el espacio de cabeza seguido de cromatografía gaseosa acoplada a espectrometría de masas (HS-SPME GC-MS)

The aim of the present study was to determine the main constituents of Scrophularia striata essential oil and to evaluate in vitro effect of essential oil on Leishmania tropica and Leishmania major promastigotes and axenic amastigotes. Chemical constituents of the extracted essential oil were separated by headspace solid-phase microextraction (HS-SPME) equipped with a PDMS/DVB fiber. The fiber was injected to gas chromatogram- mass spectroscopy (GC-MS) to determine their identity. Finally, after exposure of parasites to different concentrations of water soluble fraction of essential oil, viability of promastigotes and axenic amastigotes were investigated. Based on the HS-SPME results, 47 compounds representing 95.6% of the total oil, were identified in essential oil. Essential oil analysis showed that nonane (19.7%), α-terpineol (17.4%) and linalool (10.2%) were the most abundant compounds. This study indicates that water soluble fraction of S. striata essential oil has promising anti-leishmanial activity.

El objetivo del presente estudio fue determinar los principales componentes del aceite esencial de Scrophularia striata y evaluar el efecto in vitro del aceite esencial en promastigotes y amastigotes axénicos de Leishmania tropica y Leishmania major. Los componentes químicos del aceite esencial extraído se separaron mediante microextracción de fase sólida en el espacio superior (HS-SPME) equipado con una fibra PDMS/DVB. Para determinar su identidad la fibra se inyectó en un cromatógrafo de gases acoplado un espectrómetro de masas (GC-MS). Finalmente, después de la exposición de los parásitos a diferentes concentraciones de fracción soluble del aceite esencial en agua, se investigó la viabilidad de los promastigotes y los amastigotes axénicos. En base a los resultados de HS-SPME, se identificaron 47 compuestos que representan el 95.6% del aceite total en el aceite esencial. El análisis de aceites esenciales mostró que el nonano (19.7%), el α-terpineol (17.4%) y el linalol (10.2%) fueron los compuestos más abundantes. Este estudio indica que la fracción soluble en agua del aceite esencial de S. striata tiene una actividad antileishmanial prometedora.

Multivariate optimization of a HS-SPME/GC-MS technique for the characterization of volatile compounds present in Hedeoma multiflorum Benth / Optimización Multivariada de una técnica HS-SPME/GC para la caracterización de los compuestos volátiles presentes en Hedeoma multiflorum Benth

The aim of the present work was to optimize the main experimental variables of a procedure using HS-SPME/GC-MS as the analytical methodology to establish the profile of the volatile compounds present in aerial parts of Hedeoma multiflorum Benth. The influence of the type of fiber, equilibrium time, extraction time and extraction temperature on the composition of the volatile compounds was determined using response surface methodology (RSM), and the parameters of the models were corroborated by multiple linear regressions. The results showed that the regression models generated adequately explained the data variation and represented the relationships between the parameters and their responses. The optimal analysis conditions from the contour plots were established (DVB/CAR/PDMS fiber, with a 10 min equilibrium time, 10 min extraction time, and 40°C). Under these conditions, 41 volatile components in the whole plant were determined, which represents more than those reported using hydrodistillation.

El objetivo del presente trabajo fue optimizar las principales variables experimentales de un procedimiento HS-SPME/GC para establecer el perfil de compuestos volátiles presentes en la parte aérea de Hedeoma multiflorum Benth. Se determinó la influencia de las variables tipo de fibra, tiempo de equilibrio, tiempo de extracción y temperatura de extracción sobre la composición de los volátiles, utilizando una met odología de superficie de respuesta (RSM) y los parámetros del modelo se corroboraron por regresión lineal múltiple. Los resultados demostraron que los modelos de regresión generados explican adecuadamente la variación de los datos y representaron significativamente las relaciones reales entre los parámetros y sus respuestas. Las condiciones óptimas de análisis fueron establecidas (DVB/CAR/PDMS, con un tiempo de equilibrio de 10 minutos, un tiempo de extracción de 10 minutos y trabajando a 40°C). Utilizando esta metodología, se determinaron 41 componentes volátiles en planta entera, más que los reportados mediante hidrodestilación.

An Integrated Air Monitoring Approach for Assessment of Formaldehyde in the Workplace

The aim of this study is to validate an integrated air monitoring approach for assessing airborne formaldehyde (FA) in the workplace. An active sampling by silica gel impregnated with 2,4-dinitrophenylhydrazine, a passive solid phase microextraction technique using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine as on-fiber derivatization reagent, an electrochemical direct-reading monitor, and an enzyme-based badge were evaluated and tested over a range of 0.020–5.12 ppm, using dynamically generated FA air concentrations. Simple linear regression analysis showed the four methods were suitable for evaluating airborne FA. Personal and area samplings in 12 anatomy pathology departments showed that the international occupational exposure limits in the GESTIS database were frequently exceeded. This monitoring approach would allow a fast, easy-to-use, and economical evaluation of both current work practices and eventual changes made to reduce FA vapor concentrations.

Uso da microextração por sorbente empacotado (MEPS) para preparo de amostras em análises toxicológicas envolvendo fármacos benzodiazepí­nico / Microextraction by packed sorbent (MEPS) for sample preparation in toxicological analyses involving benzodiazepines

A microextração por sorbente empacotado (MEPS) é uma técnica de preparo de amostras ainda pouco utilizada no âmbito da toxicologia, em que os mesmos princípios da extração em fase sólida convencional são adaptados para uma escala miniaturizada. As principais vantagens da técnica estão associadas ao pequeno volume de amostra e de solventes utilizados, à possibilidade de realizar múltiplas extrações com um mesmo cartucho e à facilidade de automação. Os benzodiazepínicos possuem grande relevância na toxicologia dada sua ampla utilização e seus efeitos que podem, por exemplo, comprometer a capacidade de dirigir, além do uso abusivo, e como drogas facilitadoras de crimes. Neste trabalho, um método de MEPS foi desenvolvido e otimizado para a determinação de sete benzodiazepínicos e seus produtos de biotransformação (diazepam, clonazepam, flunitrazepam, alprazolam, bromazepam, 7-aminoflunitrazepam e nordiazepam) utilizando 100 µL de amostra de sangue total post mortem. Após a extração, os eluatos foram analisados por cromatografia líquida em fase reversa acoplada a espectrometria de massas. O método foi validado de acordo com as recomendações do Scientific Working Group for Forensic Toxicology, apresentando linearidade adequada de 5 a 500 ng.mL-1 . Os valores de exatidão (90,4 a 109,5%), precisão intra-dia (2,5 a 10,7 %CV) e inter-dia (1,1 a 8,0 %CV) também foram satisfatórios. MEPS foi realizada mais de 60 vezes com a mesma fase extratora sem evidências de contaminação cruzada. Dez amostras reais fornecidas pelo Instituto Médico Legal de São Paulo foram analisadas. Foram quantificados diazepam, nordiazepam, clonazepam e bromazepam. Os resultados encontrados em cada uma das amostras foram comparados com dados da literatura

Microextraction by packed sorbent (MEPS) is a sample preparation technique still little used in toxicology, where the same principles of conventional solid phase extraction are adapted to a miniaturized scale. The main advantages of the technique are associated with the small volume of sample and solvents required, the possibility of performing multiple extractions with the same cartridge and ease process automation. Benzodiazepine drugs are relevant in toxicology because of their widespread use, and effects (which may, for example, compromise the ability to drive vehicles), abuse and records as crime-facilitating drugs. In this work, a MEPS method was developed and optimized for a determination of seven benzodiazepines and their metabolites (diazepam, nordiazepam, clonazepam, flunitrazepam, 7-aminoflunitrazepam, alprazolam, and bromazepam) using 100 µL of post mortem whole blood. After extraction, the eluates were analyzed by reversed-phase liquid chromatography coupled to mass spectrometry. The method was validated according to the recommendations of the Scientific Working Group for Forensic Toxicology, presenting adequate linearity from 5 to 500 ng.mL-1 . The values of accuracy (90.4 to 109.5%), intra-day precision (2.5 to 10.7 %CV) and inter-day (1.1 to 8.0 %CV) also presented satisfactory results. MEPS was performed more than 60 times with the same extractive phase without compromising the results with the evidence of carryover. Institute of Legal Medicine were submitted to analysis by MEPS-LC-MS/MS. In these samples, the following analytes were quantified: diazepam, nordiazepam, clonazepam and bromazepam. The results found in each of the samples were compared with data from the literature

Prospecção de compostos orgânicos voláteis e seus efeitos na auto-regulação fisiológica em cianobactérias / Prospection of volatile organic compounds and their effects on physiological self-regulation in cyanobacteria

Apesar dos diversos estudos sobre a presença de cianobactérias e a correlação entre fatores ambientais que influenciam ou desencadeiam florações, é ainda incipiente a informação sobre o controle fisiológico e bioquímico da produção de metabólitos secundários, cianotoxinas e compostos orgânicos voláteis (COVs) nestes organismos. Os COVs mais comumente encontrados em cianobactérias são a geosmina e o 2- metil-isoborneol, compostos que resistem ao tratamento convencional da água, causam mau cheiro e alteram seu gosto, além de bioacumular em peixes e moluscos. Estudos sobre possíveis sistemas de competição (alelopatia) entre linhagens de cianobactérias, ou entre elas e outros organismos, podem contribuir para elucidação do papel da produção de COVs por cianobactérias. Dessa forma, os objetivos deste projeto foram (i) prospectar a produção de COVs e seus efeitos na auto-regulação fisiológica em cianobactérias mantidas em laboratório; e (ii) desenvolver um método analítico, por microextração em fase sólida (SPME) e cromatografia em fase gasosa com detecção por espectrometria de massas (GC-MS), para a determinação destes compostos. Foram realizados ensaios para avaliar os perfis de produção dos COVs em duas linhagens de M. aeruginosa em diferentes fases de crescimento, sob diferentes intensidades luminosas (50, 150 e 250 ?µmol.fótons.m-2.s-1) e também ao longo do ritmo circadiano, avaliando a influência dos períodos claro e escuro. Para avaliar efeitos alelopáticos, exsudatos de uma linhagem de M. aeruginosa produtora de microcistinas foram testados em culturas de outra linhagem de M. aeruginosa não produtora de toxinas por meio de técnicas tradicionais de cultivo com monitoramento do crescimento. Na análise da produção de COVs, por GC-MS, observou-se que se destacam, majoritariamente, os compostos α-ciclocitral, ß-ciclocitral e ß-ionona, sendo o ß-ciclocitral o mais abundante, em todas as condições testadas, para as ambas as linhagens estudadas. A linhagem não toxigênica, no entanto, apresentou produção mais elevada de todos os compostos identificados. Dentre as intensidades luminosas testadas, a intensidade de 250 µmol.fótons.m-2s-1 foi a que apresentou a maior taxa de crescimento para a linhagem LTPNA 08 e relação negativa entre o aumento da irradiância e a produção de ß-ciclocitral. Foram identificadas, também, variações na produção dos compostos α-ciclocitral, ß-ciclocitral e ß-ionona nas linhagens ao longo do ritmo circadiano, sendo as maiores concentrações encontradas no período escuro. Observou-se morte celular e redução na produção de COVs 24 horas após adição de exsudatos pertencentes à linhagem de M. aeruginosa toxigênica em cultivos da linhagem não-toxigênica. Sendo assim, pode-se inferir que a produção dos COVs pode sofrer alterações qualitativas e quantitativas dependendo do estímulo ambiental presente, tanto por interações bióticas (com outros organismos e ritmo circadiano), quanto por fatores abióticos (intensidade luminosa)

There are several studies on the presence of cyanobacteria and the correlation between environmental factors that may influence or trigger blooms. However, information concerning the physiological and biochemical control of the production of secondary metabolites, toxins and volatile organic compounds (VOC) by cyanobacteria is poorly understood. Geosmin and 2-methyl-isoborneolare are commonly found VOC in cyanobacteria, they resist to conventional water treatment and can cause bad smell and taste in the final water. In addition, VOC can bioaccumulate in fish and shellfish. Studies on possible competition systems (allelopathy) either among strains of cyanobacteria or among them and other organisms such as green microalgae, may help to elucidate the role of VOC production by cyanobacteria. Thus, the main objectives of this study are: (i) prospect the production of VOCs and their effects on physiological self-regulation in cyanocrobacteria kept in the laboratory; and (ii) to develop an analytical method, by solid phase microextraction (SPME) and gas chromatography with mass spectrometry detection (GC-MS), for the determination of these compounds. The assays were carried out to evaluate the production profiles of VOCs in two strains of M. aeruginosa at different growth stages under different light intensities (50, 150 and 250 µmol.fótons.m-2.s-1) and also along of the circadian rhythm, evaluating the influence of light and dark periods. To assess allelopathic effects, exudates from a microcystin-producing strain of M. aeruginosa were tested on cultures of another non-toxin producing M. aeruginosa strain by traditional growth monitoring culture techniques. In the analysis of VOC production by GC-MS, it was observed that α-cyclocyclal, ß-cyclocyclal and ß-ionone compounds were the most prominent, with ß-cyclocitral being the most abundant in all conditions tested, for both strains studied. The non-toxigenic lineage, however, showed higher production of all the identified compounds. Among the light intensities tested, the intensity of 250 µmol.fótons.m-2s-1 was the one with the highest growth rate and positive relation between the irradiance increase and the ß-cyclocitral production. Variations in the production of the α-cyclocyclal, ß-cyclocyclal and ß-ionone compounds were also identified in the lines along the circadian rhythm, being the highest concentrations found in the dark period. Cell death and reduction in VOC production were observed 24 hours after addition of exudates belonging to the toxigenic M. aeruginosa lineage in cultures of the non-toxigenic lineage. Thus, it can be inferred that the production of VOCs can undergo qualitative and quantitative changes depending on the environmental stimulus present, both by biotic interactions (with other organisms and circadian rhythm) and by abiotic factors (luminous intensity)

Relationship between the Change Rules of Volatile Organic Compounds in Rat Muscle and Postmortem Interval / 法医学杂志

OBJECTIVES@#To explore the relationship between the change rules of volatile organic compounds （VOCs） in rat muscle and postmortem interval （PMI）.@*METHODS@#A total of 120 healthy rats were divided randomly into 12 groups （10 for each group）. After the rats were sacrificed by cervical dislocation, the bodies were kept at （25±1） ℃. Rat muscle samples were separately obtained at 12 PMI points, including 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 d. The VOCs in rat muscles were collected, detected and analyzed by headspace solid-phase microextraction （HS-SPME） coupled to gas chromatography-mass spectrometer （GC-MS）.@*RESULTS@#In total, 15 species of VOCs were identified, including 9 aromatic compounds, 3 sulfur compounds, 2 aliphatic acids and 1 heterocyclic compound. The species of VOCs increased with PMI： no species were detected within 1 day, 3 species were detected on day 2, 9 on day 3, 11 on day 4, 14 from day 5 to 7, and 15 from day 8 to 10. Total peak area of 15 species of VOCs was significantly correlated to PMI （adjusted R²=0.15-0.96）： the regression function was y=-17.05 x²+ 164.36 x-246.36 （adjusted R²=0.96） from day 2 to 5, and y=2.24 x+101.13 （adjusted R²=0.97） from day 6 to 10.@*CONCLUSIONS@#The change rules of VOCs in rat muscle are helpful for PMI estimation.

Volatile compounds profile of Bromeliaceae flowers / Perfil de compuestos volátiles de las flores en las Bromeliaceae

Abstract:Volatile compounds play a vital role in the life cycle of plants, possessing antimicrobial and anti-herbivore activities, and with a significant importance in the food, cosmetic, chemical, and pharmaceutical industry. This study aimed to identify the volatile compounds emitted by flowers of thirteen species belonging to four genera of Bromeliaceae, using headspace solid-phase micro-extraction and detection by gas chromatography-mass spectrometry. A total of 71 volatile compounds belonging to nine chemical groups were identified. The compounds identified represented more than 97 % of the major components in Aechmea bicolor, Ae. bromeliifolia, Ae. distichantha, Ae. fasciata, and Vriesea friburgensis. In the Ananas varieties, over 99 % of the components were identified, and around 90 % in V. simplex. V. friburgensis presented the largest diversity of volatiles with 31 compounds, while Alcantarea nahoumii presented only 14. All three Ananas varieties presented the same 28 compounds in relatively similar abundance, which has been confirmed by principal component analysis. Current taxonomy and pollination syndrome studies available can adequately explain the variation in volatile compounds among species. Rev. Biol. Trop. 64 (3): 1101-1116. Epub 2016 September 01.

ResumenLos compuestos volátiles tienen un papel vital en el ciclo de vida de las plantas. Poseen actividad antimicrobiana y anti-herbivoría biológica y una gran importancia en la industria de alimentos, cosméticos, perfumes, productos químicos y farmacéuticos. Este estudio tuvo como objetivo identificar los compuestos volátiles de trece flores de especies, pertenecientes a cuatro géneros de Bromeliaceae utilizando microextracción en fase sólida mediante cromatografía de gases hifenada con espacio de cabeza acoplada a espectrometría de masas. Se han identificado setenta y un diferentes compuestos volátiles pertenecientes a nueve grupos. Los compuestos identificados representaron más del 97 % de los componentes principales en Aechmea bicolor, Ae. bromeliifolia, Ae. distichantha, Ae. fasciata, Vriesea friburgensis, 99 % en las variedades de Ananas y 90 % en V. Simplex. V. friburgensis mostró la mayor diversidad de compuestos volátiles con 31, mientras que en Al. nahoumii se han encontrado sólo 14 compuestos. Las tres variedades de Ananas presentan los mismos 28 compuestos en cantidades relativamente similares, lo que se confirmó por el análisis de componentes principales. Estudios taxonómicos y síndromes de polinización disponibles podrían explicar la variación de los compuestos volátiles entre especies.

Volatile organic compounds from pachyrhizus ferrugineus and pachyrhizus erosus (Fabaceae) leaves / Compuestos orgánicos volátiles de las hojas de pachyrhizus ferrugineus y pachyrhizus erosus (Fabaceae)

In México, Pachyrhizus erosus (Fabaceae) commonly called "jícama", is widely known for its edible tubers. It is cultivated since the pre-Columbian period, and the powdered seeds have been used for the treatment of mange, lice, and fleas, due to their content of rotenone, a well-known insecticidal compound. On the other hand, P. ferrugineus, a wild species can only be found in the Tropical Forests, and has no commercial value. It is known that plants release volatile organic compounds (VOCs) showing qualitative and quantitative differences if are wild or cultivated. VOCs are also involved as repelling or attracting chemical signals to insect herbivores, and their natural enemies. Until now, the VOCs of the leaves of P. erosus and P. ferrugineus have not been investigated. In the present contribution the VOCs of both species were characterized by headspace solid-phase (HS-SPME) extraction and gas chromatography-mass spectrometry (GC-MS-TOF). In P. erosus 21 VOCs were found, being the most abundant: cyclohexanone (32.8 percent), 3-hexen-1-ol (Z) (32.7 percent), 3-hexenal (Z) (10.5 percent). The majoritarian compounds were C6 or C5 derivatives In P. ferrugineus, the most abundant VOCs were: 5-hexene-1-ol acetate (51.5 percent), undecanal (22.4 percent), 2-hepten-1-al (14.5 percent). The majoritarian compounds were C6, C7 or C11 derivatives.

En México, Pachyrhizus erosus (Fabaceae) es llamada comúnmente "jícama" y es conocida por sus tubérculos comestibles. Se ha cultivado desde el período pre-Colombino y las semillas se han utilizado para el tratamiento tópico de la sarna, piojos, pulgas; las semillas contienen rotenona, un compuesto insecticida. Por otra parte, P. ferrugineus solo está presente en estado silvestre en los bosques tropicales y carece de valor comercial. Se sabe que las plantas liberan compuestos orgánicos volátiles (COV) y muestran diferencias cualitativas y cuantitativas dependiendo, si son silvestres o cultivadas. Los COV también son señales químicas atrayentes o repelentes de los insectos herbívoros y a sus enemigos naturales. Hasta ahora, los COV en las hojas de P. erosus y P. ferrugineus no han sido investigados. En el presente trabajo, los COV se identificaron mediante la microextracción (HS-SPME) en fase sólida, e identificados por cromatografía de gases acoplada a espectrometría de masas (GC-MS-TOF). En P. erosus se encontraron 21 COV, siendo los más abundantes: ciclohexanona (32.8 por ciento), 3-hexen-1-ol (Z) (32.7 por ciento) y 3-hexenal (Z) (10.5 por ciento). Los compuestos mayoritarios son C6 y C5. En P. ferrugineus los más abundantes fueron: 5-hexen-1-ol acetato (51.5 por ciento), undecanal (22.4 por ciento) y 2-hepten-1-al (14.5 por ciento). Los compuestos mayoritarios son C6, C7 o C11.

Comparison of volatile compounds in Retanilla trinervia [Gillies & Hook] Hook & Arn honeys from central Chile / Comparación de compuestos volátiles en mieles de Retanilla trinervia[Gillies & Hook] Hook & Arn de Chile Central

The search for chemical markers for determining honey authenticity as a complementary tool for melissopalynological method is an important issue in the study of honeys from different botanical origins. The objective of this study was to determine the volatile compounds in tevo (Retanilla trinervia [Gillies & Hook] Hook & Arn [Fam. Rhamnaceae]) honey as one of the most relevant honeys from central Chile. For the identification and quantification of volatile compounds, Solid-Phase Microextraction and Gas Chromatography with Mass Spectrometry (SPME-GC-MS) was performed. A total of 28 out of 103 volatile compounds were found common to the five tevo honeys analyzed. Nevertheless, these compounds are common in unifloral honey of different floral sources from other countries. These results represent the first record in the identification of volatile compounds in tevo honey and would indicate that tevo honey does not present specific volatile compounds that allow its clear differentiation from other unifloral honey.

La búsqueda de marcadores químicos para determinar la autenticidad de la miel como una herramienta complementaria al análisis melisopalinológico es un tema importante en el estudio de las mieles de diferentes orígenes botánicos. El objetivo de este estudio fue determinar los compuestos volátiles en miel de tevo (Retanilla trinervia [Gillies & Hook] Hook & Arn [Fam. Rhamnaceae]), una de las mieles más relevantes de Chile Central. La identificación y cuantificación de compuestos volátiles se llevó a cabo mediante Microextracción en Fase Sólida y Cromatografía de Gases con Espectrometría de Masas (SPME-CG-MS). Un total de 28 de los 103 compuestos volátiles identificados en las cinco mieles de tevo analizadas se encontraron en común para ellas. Sin embargo, estos compuestos son comunes en la miel monofloral de diferentes fuentes florales de otros países. Estos resultados representan los primeros avances en la identificación de compuestos volátiles en la miel de tevo e indicarían que la miel de tevo no presenta compuestos volátiles específicos que permitan su clara diferenciación respecto a otras mieles monoflorales.

Readspace solid-phase microextraction-gas chromatography for determination of 2,5-hexanedione in urine / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a method for determination of 2,5-hexanedione in urine by headspace solid-phase microextraction-gas chromatography.</p><p><b>METHODS</b>After extraction by solid-phase microextraction head, 2,5-hexanedione in urine was determined by gas chromatography and was quantified by external standard method.</p><p><b>RESULTS</b>The concentration of 2,5-hexanedione in urine showed a linear relationship within the range of 0.1-20.0 µg/ml. The regression equation was y=261.36x-1.903 3, r=0.999 2. The minimum detectable concentration was 0.01 µg/ml. The recovery rate was 92.6%-97.1%, with a relative standard deviation (RSD) of 3.3%-5.8%. The intra-day and inter-day RSDs were 3.8%-6.2% and 4.7%-6.3% respectively.</p><p><b>CONCLUSION</b>This determination method has no requirement for organic solvents, features simple and rapid operation, possesses higher detection sensitivity, and applies well to the determination of 2,5-hexanedione in urine.</p>

Detection of Organochlorine Compounds Formed During the Contact of Sodium Hypochlorite with Dentin and Dental Pulp

This study used gas chromatography-mass spectrometry (GC-MS) to detect the products formed during the contact of sodium hypochlorite (NaOCl) with bovine pulp and dentin. For analysis of the products formed in the volatile phase, 11 mg of bovine pulp tissue were placed in contact with 0.5%, 2.5% and 5.25% NaOCl until complete tissue dissolution occurred. The solid phase microextraction (SPME) fiber was exposed inside the container through the cover membrane and immediately injected into the GC-MS system. 30 mg of the of dentin were kept in contact with NaOCl, and then the SPME fiber was exposed inside the container through the cover membrane for adsorption of the products and injected into the GC-MS system. The same protocol was used for the aqueous phase. For analysis of the volatile compounds, the final solution was extracted using pure ethyl ether. The suspended particulate phase of the mixture was aspirated, and ether was separated from the aqueous phase of the solution. The ether containing the products that resulted from the chemical interaction of dentin and pulp with the NaOCl was filtered and then injected into the GC-MS system for analysis of the aqueous phase. The aqueous and volatile phases of both dentin and pulp showed the formation of chloroform, hexachloroethane, dichloromethylbenzene and benzaldehyde. In conclusion, organochlorine compounds are generated during the contact of dentin and pulp with NaOCl at concentrations of 0.5%, 2.5% and 5.25%.

Este estudo utilizou a cromatografia gasosa acoplada a espectrometria de massa (CG-MS) para detectar os produtos que se formaram durante o contato de hipoclorito de sódio (NaOCl) com polpa dental bovina e dentina. Para a análise dos produtos formados na fase volátil, 11 mg de polpa bovina foram colocados em contato com 0,5 % , 2,5 % e 5,25 % de NaOCl, até à dissolução completa dos tecidos. A fibra de microextração em fase sólida (SPME) era exposta dentro do recipiente através da membrana da tampa, por 15 minutos, para a adsorção dos produtos formados e imediatamente injetada no CG-MS para análise. Para a análise da dentina, 30 mg do de amostras foram mantidas em contacto com o NaOCl, por 15 min, e então a fibra de SPME era exposta no interior do recipiente através da membrana de cobertura para a adsorção dos produtos e injectado no sistema de GC-MS. O mesmo protocolo foi utilizado para a fase aquosa. Para a análise dos compostos voláteis, a solução final foi extraída com éter etílico puro. A fase de partículas em suspensão da mistura foi aspirada, e o éter foi separado da fase aquosa da solução. O éter contendo os produtos que resultaram da interacção química da dentina e polpa com hipoclorito de sódio foi filtrado e, em seguida, injectado no sistema GC-MS para análise da fase aquosa. As fases aquosas e voláteis de dentina e polpa mostraram a formação de clorofórmio, hexacloroetano, dichloromethylbenzene e benzaldeído. Compostos organoclorados são gerados durante o contacto da dentina e polpa com hipoclorito de sódio em concentrações de 0,5 % , 2,5 % e 5,25 %.

Determination of volatile organic compounds of Tagetes filifolia Lag. (Asteraceae) from Córdoba (Argentina) using HS-SPME analysis / Determinación de compuestos orgánicos volátiles de Tagetes filifolia Lag. (Asteraceae) proveniente de Córdoba (Argentina) utilizando análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC–FID) are described for the analysis of volatile compounds in Tagetes filifolia Lag. The composition of the total aerial parts of the plant (whole plant) and the inflorescences, leaves and stems were studied separately using HS-SPME. As a result, 54 compounds were determined, of which 47 were identified. The major components observed in this analysis were trans-anethole and estragole. The HS-SPME method used for the analysis of volatile compounds of T. filifolia is simple, fast, effective, free from the use of solvents, and permits by an analysis of small amounts of samples to achieve better results in terms of the determination of the composition than those reported in the literature for the analysis of essential oil.

Se realizó el análisis de los componentes volátiles de Tagetes filifolia Lag. utilizando el método de microextracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudio la composición de la planta entera así como también la de las inflorescencias, hojas y tallos por separado empleando el método de HS-SPME. Como resultado, se determinaron 54 compuestos de los cuales 47 fueron identificados. Los componentes mayoritarios observados en este análisis fueron: trans-anetol y estragol. El método de HS-SPME utilizado para el análisis de los compuestos volátiles de T. filifolia es simple, rápido, efectivo, libre de la utilización de solventes, y permitió mediante el análisis de pequeñas cantidades de muestra alcanzar mejores resultados en cuanto a la determinación de la composición, que los reportados en literatura para el análisis del aceite esencial.

Stable life predection for Mentha haplocalyx by initial average rate stability test / 中国中药杂志

<p><b>OBJECTIVE</b>To predict the stable life for Mentha haplocalyx.</p><p><b>METHOD</b>The volatiles in M. haplocalyx were analyzed by head-space solid micro-extraction, coupled with GC-MS and a comprehensive evaluation of essential oil in M. haplocalyx was analyzed using the factor analysis. The prediction was carried out by initial average rate stability tests using the content of essential oil and the main volatiles as indices.</p><p><b>RESULT</b>Principal component analysis indicated that pulegone and isomenthone can fully describe the quality of prepared slices. The t(0.9, 20 degrees C) was 5.49 years and 2.88 years respectively, carried out by essential oil, pulegone and isomenthone.</p><p><b>CONCLUSION</b>The stable life for M. haplocalyx under 20 degrees C was 2.88 years.</p>

Difference of volatile constituents contained in female and male flowers of Trichosanthes kirilowii by HS-SPME-GC-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To compare and analyze volatile constituents from flowers of Trichosanthes kirilowii, in order to point out characteristic differences between female and male flowers.</p><p><b>METHOD</b>Blooming female and male flowers were collected in the same place. Volatile constituents were extracted from the flower by solid phase micro-extraction (SPME), then separated and analyzed by gas chromatography-mass-spectrometry (GC-MS).</p><p><b>RESULT</b>Fifty-two and forty-five chromatographic peaks were separated from the female and male flowers, respectively. Forty seven constituents were identified and their relative percentage compositions were determined with the peak area normalization method. Linalool, alpha-farnesene, benzene methanol, and (Z)-2-methylbutanal oxime were the main volatile constituents. The contents of linalool and alpha-farnesene in female flower were remarkably higher than those in male. In contrast, the content of benzene methanol in male flower was remarkably higher than that in female.</p><p><b>CONCLUSION</b>In the first study on chemical constituents from flowers in genus Trichosanthes, 37 compounds are separated from T. kirilowii. Contents of linalool, alpha-farnesene and benzene methanol show the characteristic differences of volatile constituents contained in male and female flowers of T. kirilowii, which enriches the basic studies on dioecious plant.</p>

Compuestos volátiles de la guanábana colombiana (Annona muricata L. Cv. Elita) durante su maduración / Volatile compounds during the ripening of colombian soursop (Annona muricata L. Cv. Elita)

Los frutos de guanábana (Annona muricata L. cv. Elita) en diferentes estados de madurez se evaluaron para determinar las características fisico-químicas: sólidos solubles totales, porcentaje de acidez, pH e índice demadurez. Los cambios en la composición de los compuestos volátiles se determinaron mediante la técnica de Espacio de Cabeza-Microextracción en Fase Sólida y el posterior análisis por Cromatografía de gasesa coplada a espectrometría de masas. Los compuestos volátiles se identificaron por comparación de sus propiedades cromatográficas y espectrales con sustancias de referencia. Los factores de calidad sensorial mostraron valores que variaron con el estado de madurez. Además, se estableció que la cantidad de ésteres, especialmente los provenientes de los ácidos C6, C4 y C8, saturados e insaturados, se incrementaroncon la maduración. Los compuestos alifáticos C6, como el (Z)-3-hexenol y el (Z)-3- hexenal, fueronlos volátiles mayoritarios en la fruta verde; en tanto que el hexanoato de metilo y el (E)-2- hexenoato demetilo, fueron los más abundantes en las frutas maduras, sobremaduras y de madurez intermedia. En la sobremaduración aumentó la concentración de acetato de etilo, butanoato de metilo y butanoato de etilo; y aparecieron los ácidos alifáticos butanoico y hexanoico, los cuales pueden ser indicadores del inicio de la etapa fermentativa y de la pérdida de la calidad sensorial de la fruta.

Determination of volatile organic compounds of tagetes Argentina Cabrera (Asteraceae) using HS-SPME analysis / Determinación de compuestos orgánicos volátiles de tagetes Argentina Cabrera (Asteraceae) utilizando análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID) is described for the analysis of volatile compounds in Tagetes argentina Cabrera. The composition of the totality of the aerial parts of the plant (whole plant) and the inflorescences, leaves and stems was studied separately using HS-SPME. As a result, 53 compounds were determined, of which 39 were identified. The major components were: cis-tagetenone, trans-tagetenone, trans-tagetone and cis-tagetone.Using a much smaller amount of samples, a shorter extraction time and a very simple procedure, the HS-SPME method can achieve similar or better results than those obtained by EO analysis. In conclusion, the HS-SPME method is simple, rapid, effective and free of solvent, and can be used for the analysis of volatile compounds in samples of different populations of T. Argentina.

Se realizó el análisis de los componentes volátiles de T. argentina Cabrera utilizando el método de micro-extracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudio la composición de la totalidad de las partes aéreas de la planta (planta entera) como así también de las inflorescencias, hojas y tallos por separado empleando el método de HS-SPME. Como resultado, se determinaron 53 compuestos de los cuales 39 fueron identificados. Los componentes mayoritarios fueron: cis-tagetenona, trans-tagetenona, trans-tagetona and cis-tagetona. Utilizando una muy pequeña cantidad de muestra, un corto periodo de tiempo y un procedimiento muy simple se lograron similares o mejores resultados a aquellos reportados mediante el análisis del aceite esencial. En conclusión, el método de HS-SPME es simple, rápido, efectivo, libre de la utilización de solventes y puede ser fácilmente implementado para el análisis de componentes volátiles provenientes de muestras de diferentes poblaciones de T. Argentina.

Phytochemistry of Tagetes minuta L. (Asteraceae) from Córdoba, Argentina: comparative study between essential oil and HS-SPME analyses / Fitoquímica de Tagetes minuta L. (Asteraceae) originario de Córdoba, Argentina: estudio comparativo entre análisis del aceite esencial y análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC–FID) is described for the analysis of volatile compounds in Tagetes minuta L. Five types of SPME commercial fibers including PA, PDMS, CAR-PDMS, PDMS–DVB and DVB–CAR–PDMS were investigated and the best extraction was achieved with the mixed fiber DVB–CAR–PDMS. Parameters for HS-SPME in terms of equilibrium time of HS, fiber exposition time and extraction temperature were also investigated. Additionally, the composition of inflorescences, leaves and stems was also studied separately by HS-SPME. As a result, 68 compounds were determined and 53 were identified. A comparison was made between results obtained by HS-SPME–GC–MS and steam distillation of essential oil of the aerial parts of the plant. In both analyses, the major components were: cis-tagetenone and trans-tagetenone. Using much smaller samples, a shorter extraction time and a simpler procedure, the HS-SPME method can achieve similar results to those obtained by EO analysis. In conclusion, the HS-SPME method is simple, rapid, effective and free of solvent, and can be used for the analysis of volatile compounds in samples of different populations of T. minuta.

Se realizó el análisis de los componentes volátiles de T. minuta L. utilizando el método de micro-extracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudiaron cinco tipos de fibras comerciales que incluyeron a PA, PDMS, CAR-PDMS, PDMS–DVB y DVB–CAR–PDMS y se estableció que la fibra de DVB–CAR–PDMS es la que posee mejor comportamiento en el proceso de extracción. Se determinó el efecto del tiempo de equilibrio del espacio de cabeza, de la temperatura de extracción y del tiempo de exposición de la fibra sobre el proceso de HS-SPME. Adicionalmente, también se estudio por separado la composición de inflorescencias, hojas y tallos empleando el método de HS-SPME. Como resultado de este estudio se determinaron 68 componentes de los cuales 53 fueron identificados. Por otra parte se realizó una comparación de los resultados HS-SPME con el análisis del aceite esencial obtenido de las partes aéreas de la planta. En ambos casos, los componentes mayoritarios fueron: cis-tagetenona y trans-tagetenona. Utilizando una muy pequeña cantidad de muestra, un corto periodo de tiempo y un procedimiento más simple se lograron similares resultados a los obtenidos mediante el análisis del aceite esencial. En conclusión, el método de HS-SPME desarrollado es simple, rápido, efectivo y libre de la utilización de solventes, puede ser fácilmente implementado para el análisis de componentes volátiles provenientes de muestras de diferentes poblaciones de T. minuta.