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1.
Phytochem Anal ; 35(3): 579-585, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38130156

RESUMEN

INTRODUCTION: The active compound (E)-1-(3',4'-dimethoxyphenyl)butadiene (DMPBD) isolated from the rhizomes of Zingiber cassumunar Roxb. has potent anti-inflammatory and anticancer activities. Although DMPBD is one of the promising drug candidates for phytomedicine, its limited stability impedes its widespread use. For the development of new drugs, the assessment of their chemical stability is essential, ensuring they maintain their properties within specified limits throughout the period from production until use. OBJECTIVE: In the present study, we aimed to evaluate the stability of DMPBD under various conditions, including different solvents, temperatures, and lighting conditions, to identify the factors affecting stability and optimize the storage and handling conditions. METHODOLOGY: DMPBD samples subjected to the different conditions tested were monitored by quantitative 1H NMR (qHNMR), using an internal standard for the determination of the absolute quantity of DMPBD as a function of time and the changes thereof within 1 month. RESULTS: Significant decomposition of DMPBD was observed in chloroform-d1, whereas its content remained constant in methanol-d4. The content of DMPBD was maintained upon storage at temperatures below 4°C, both as methanolic solution and in the crude extract. Exposure to light had a slight negative impact on its contents. Some degradation products could be identified as resulting from O2-induced cleavage of the diene moiety. CONCLUSIONS: For pharmacological/therapeutic applications, DMPBD should be stored in the form of the crude extract or as a purified material in methanolic solution. Ideally, the storage temperature should be below 4°C and O2 should be excluded.


Asunto(s)
Extractos Vegetales , Zingiberaceae , Extractos Vegetales/química , Butadienos/análisis , Butadienos/farmacología , Rizoma/química , Zingiberaceae/química
2.
Sci Total Environ ; 850: 157983, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-35973540

RESUMEN

Freshwater pollution is a huge concern. A study aiming to evaluate physico-chemical characteristics, microbiota, occurrence of two groups of persistent environmental pollutants with similar chemical properties (polycyclic aromatic hydrocarbons- PAHs and microplastics - MPs) in Alqueva's surface water was performed during 2021. Water samples were collected at three spots related to touristic activities (two beaches and one marina) during the Winter, Spring, Summer and Autumn seasons. In addition, the presence of biofilms on plastic and natural materials (stone, wood/ vegetal materials) were assessed and compared. Water quality based on physicochemical parameters was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters by international organizations. However, carcinogenic compounds were detected in two sampling locations, which can pose a problem for aquatic ecosystems. PAHs profiles showed significant differences when comparing the dry seasons with the rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weigh compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during the Winter season. The polymers detected were poly(methyl-2-methylpropenoate), polystyrene, polyethylene terephthalate, polyamide, polypropylene, styrene butadiene, polyvinyl chloride and low /high density polyethylene with the last being the most frequent. Biofilms were more often detected on plastics than on natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity (e.g., bacteria, fungi/yeast and phytoplancton organisms) and richer in extrapolymeric material. Based on morphological analysis a good agreement between microbiota and microorganism present in the biofilms was found. Among microbiota were identified microorganisms previously linked to plastic and PAHs detoxification suggesting the need for further studies to evaluate the viability of using biofilms as part of a green bioremediation strategy to mitigate water pollution.


Asunto(s)
Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Biopelículas , Butadienos/análisis , Ecosistema , Monitoreo del Ambiente , Microplásticos , Nylons , Petróleo/análisis , Plásticos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Polietileno/análisis , Tereftalatos Polietilenos , Polipropilenos/análisis , Poliestirenos/análisis , Cloruro de Polivinilo/análisis , Contaminantes Químicos del Agua/análisis
3.
ACS Sens ; 3(3): 677-683, 2018 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-29443518

RESUMEN

Isoprene is a versatile breath marker for noninvasive monitoring of high blood cholesterol levels as well as for influenza, end-stage renal disease, muscle activity, lung cancer, and liver disease with advanced fibrosis. Its selective detection in complex human breath by portable devices (e.g., metal-oxide gas sensors), however, is still challenging. Here, we present a new filter concept based on activated alumina powder enabling fast and highly selective detection of isoprene at the ppb level and high humidity. The filter contains high surface area adsorbents that retain hydrophilic compounds (e.g., ketones, alcohols, ammonia) representing major interferants in breath while hydrophobic isoprene is not affected. As a proof-of-concept, filters of commercial activated alumina powder are combined with highly sensitive but rather nonspecific, nanostructured Pt-doped SnO2 sensors. This results in fast (10 s) measurement of isoprene down to 5 ppb at 90% relative humidity with outstanding selectivity (>100) to breath-relevant acetone, ammonia, ethanol, and methanol, superior to state-of-the-art isoprene sensors. Most importantly, when exposed continuously to simulated breath mixtures (four analytes) for 8 days, this filter-sensor system showed stable performance. It can be incorporated readily into a portable breath isoprene analyzer promising for simple-in-use monitoring of blood cholesterol or other patho/physiological conditions.


Asunto(s)
Óxido de Aluminio/química , Butadienos/análisis , Filtración/métodos , Hemiterpenos/análisis , Humanos , Humedad , Interacciones Hidrofóbicas e Hidrofílicas , Nanoestructuras/química , Platino (Metal)/química , Propiedades de Superficie , Compuestos de Estaño/química
4.
New Phytol ; 220(3): 773-784, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29120052

RESUMEN

The emission of isoprenoids (e.g. isoprene and monoterpenes) by plants plays an important defensive role against biotic and abiotic stresses. Little is known, however, about the functional traits linked to species-specific variability in the types and rates of isoprenoids emitted and about possible co-evolution of functional traits with isoprenoid emission type (isoprene emitter, monoterpene emitter or both). We combined data for isoprene and monoterpene emission rates per unit dry mass with key functional traits (foliar nitrogen (N) and phosphorus (P) concentrations, and leaf mass per area) and climate for 113 plant species, covering the boreal, wet temperate, Mediterranean and tropical biomes. Foliar N was positively correlated with isoprene emission, and foliar P was negatively correlated with both isoprene and monoterpene emission rate. Nonemitting plants generally had the highest nutrient concentrations, and those storing monoterpenes had the lowest concentrations. Our phylogenetic analyses found that the type of isoprenoid emission followed an adaptive, rather than a random model of evolution. Evolution of isoprenoids may be linked to nutrient availability. Foliar N and P are good predictors of the type of isoprenoid emission and the rate at which monoterpenes, and to a lesser extent isoprene, are emitted.


Asunto(s)
Butadienos/análisis , Hemiterpenos/análisis , Nitrógeno/metabolismo , Fósforo/metabolismo , Plantas/metabolismo , Compuestos Orgánicos Volátiles/análisis , Clima , Modelos Teóricos , Filogenia , Análisis de Componente Principal
5.
Int J Nanomedicine ; 12: 2469-2476, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28408818

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the antioxidant and anti-inflammatory activities of Plai oil-encapsulated niosomes (Zingiber cassumunar Roxb.) on inflamed subcutaneous Wistar rat skin by therapeutic ultrasound. METHODS: Pure oil from Plai rhizomes was extracted by steam distillation, and antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Bioactive compounds were analyzed by gas chromatography-mass spectrometry. Niosome particles containing Plai oil were prepared by chloroform film method with sonication before testing for anti-inflammatory activity on locally inflamed subcutaneous rat skin after inducement from lipopolysaccharide with ultrasound once a day for 3 days. Skin temperatures and blood flow were evaluated. RESULTS: Plai oil presented antioxidant activity that inhibited 2,2-diphenyl-1-picrylhydrazyl radicals. Four active compounds found in the essential oil were sabinene, γ-terpinene, terpinene-4-ol, and (E)-1-(3,4-dimethyoxy phenyl) butadiene. Application of ultrasound (0.2 W/cm2, 20%, 3 min) with gel containing Plai oil-encapsulated niosomes decreased skin temperature and blood flow to the lowest level compared to the application of neurofen drug or gel-based control. CONCLUSION: Plai oil, which consists of four main bioactive compounds and possesses antioxidant and anti-inflammatory activities, can be applied against local subcutaneous inflammation when used with therapeutic ultrasound via entrapped niosomes.


Asunto(s)
Antiinflamatorios/farmacología , Aceites Volátiles/química , Ultrasonido , Zingiberaceae/química , Animales , Antioxidantes/farmacología , Monoterpenos Bicíclicos , Compuestos de Bifenilo/química , Butadienos/análisis , Monoterpenos Ciclohexánicos , Cromatografía de Gases y Espectrometría de Masas , Liposomas , Modelos Animales , Monoterpenos/análisis , Picratos/química , Extractos Vegetales/química , Ratas Wistar , Flujo Sanguíneo Regional/efectos de los fármacos , Piel/irrigación sanguínea , Piel/efectos de los fármacos , Temperatura Cutánea
6.
Environ Sci Technol ; 48(3): 1525-31, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24401031

RESUMEN

Although hexachlorobutadiene (HCBD) was recently proposed as a candidate persistent organic pollutant (POP) under the Stockholm Convention, information about its environmental levels and distributions is still very limited. In this work, HCBD was determined in the sewage sludge from 37 wastewater treatment plants (WWTPs) in 23 cities and 17 soils near a chemical plant in China. Three chlorobenzenes (CBs) (1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, and hexachlorobenzene) were simultaneously studied to help better understand the environmental behavior of HCBD. Concentrations of HCBD in sludge samples ranged from <0.03 to 74.3 ng/g dry weight (dw) with a median value of 0.30 ng/g dw, which was lower than those of the three CBs. Levels of HCBD were not correlated with capacity of the WWTPs and total organic carbon. For soils, high level of HCBD was found in the sample within the plant, with a rapid decreasing concentration trend with the increase of distance from the plant. It was suspected that releasing as a byproduct during manufacturing of chlorinated chemicals was the primary source of HCBD in the studied location. Further risk assessment indicated that the environmental risk of HCBD to soil organisms and the health risk to employees were very low through soil exposure within the plant.


Asunto(s)
Butadienos/análisis , Clorobencenos/análisis , Monitoreo del Ambiente/métodos , Contaminantes del Suelo/análisis , Aguas Residuales/química , Purificación del Agua/métodos , China , Aguas del Alcantarillado/química , Suelo/química , Suelo/normas
7.
Int J Toxicol ; 33(1 Suppl): 4S-16S, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24351873

RESUMEN

Petroleum-derived substances are complex and composed of aliphatic (normal-, iso-, and cycloparaffins), olefinic, and/or aromatic constituents. Approximately 400 of these complex substances were evaluated as part of the US Environmental Protection Agency voluntary High Production Volume (HPV) Challenge program. The substances were separated into 13 groups (categories), and all available data were assessed. Toxicology testing was conducted as necessary to fully address the end points encompassed by the HPV initiative. In a broad sense, volatile hydrocarbons may cause acute central nervous system effects, and those that are liquids at room temperature pose aspiration hazards if taken into the lungs as liquids and may also cause skin irritation. Higher boiling substances may contain polycyclic aromatic constituents (PACs) that can be mutagenic and carcinogenic and may also cause developmental effects. Substances containing PACs can also cause target organ and developmental effects. The effects of aliphatic constituents include liver enlargement and/or renal effects in male rats via an α-2u-globulin-mediated process and, in some cases, small but statistically significant reductions in hematological parameters. Crude oils may contain other constituents, particularly sulfur- and nitrogen-containing compounds, which are removed during refining. Aside from these more generic considerations, some specific petroleum substances may contain unusually toxic constituents including benzene, 1,3-butadiene, and/or n-hexane, which should also be taken into account if present at toxicologically relevant levels.


Asunto(s)
Sustancias Peligrosas/toxicidad , Petróleo/análisis , Petróleo/toxicidad , Pruebas de Toxicidad/normas , Animales , Benceno/análisis , Benceno/toxicidad , Butadienos/análisis , Butadienos/toxicidad , Industria Procesadora y de Extracción/legislación & jurisprudencia , Sustancias Peligrosas/análisis , Hexanos/análisis , Hexanos/toxicidad , Masculino , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Ratas , Estados Unidos , United States Environmental Protection Agency
8.
Huan Jing Ke Xue ; 34(12): 4654-60, 2013 Dec.
Artículo en Chino | MEDLINE | ID: mdl-24640904

RESUMEN

Using a portable gas chromatography and mass spectrometry (GC-MS), the volatile organic compounds (VOCs) pollution in each unit of the wastewater treatment system for vitamin C production was studied, and the species characteristics of volatile organic compounds (VOCs) were analyzed and summarized. The results showed that 32 kinds of volatile organic compounds were identified, and the total mass concentration range of volatilizing VOCs was 0.9629-32.0970 mg x m(-3). The most species and the largest concentration (25 and 32.0970 mg x m(-3)) of volatilizing VOCs were found in grit chamber, which was located in the most front-end of the wastewater treatment system and was in semi-closed state. The proportion of molecular sulfide in the grit chamber was as high as 30.02%; Higher proportions of aromatic hydrocarbons were monitored in the subsequent processing units, with percentages of 21.06%-31.48%. The main types of VOCs monitored were chlorinated hydrocarbons and ketones, accounting for 6.39%-55.80% and 10.40%-58.08% of the total amount, respectively; 14 kinds of VOCs were detected in every unit of the wastewater treatment system: acetone, 2-butanone, n-hexane, chloroform, chlorobenzene etc, among which, vinyl chloride, styrene and 1,3-butadiene belong to the highly toxic substances. The vinyl chloride concentration exceeded the standard of "atmospheric pollutants emission standards" (GB 16297-1996), while 1,3-butadiene and other pollutants have no national standard limits. The results of this study provide a scientific basis for the revision of China's pharmaceutical wastewater VOCs emission standards.


Asunto(s)
Contaminantes Atmosféricos/análisis , Ácido Ascórbico/química , Monitoreo del Ambiente , Compuestos Orgánicos Volátiles/análisis , Aguas Residuales/análisis , Butadienos/análisis , Butanonas/análisis , China , Industria Farmacéutica , Cromatografía de Gases y Espectrometría de Masas , Hexanos/análisis , Hidrocarburos Aromáticos/análisis , Eliminación de Residuos Líquidos
9.
Urology ; 79(5): 1118-24, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22546392

RESUMEN

OBJECTIVE: To compare the gases generated from GreenLight High-Performance System (HPS) laser prostatectomy with Urosol or normal saline solution and transurethral resection and vaporization of the prostate (TURVP) with Urosol. METHODS: A total of 36 smoke samples were collected from a continuous irrigation suction system attached to a Tenax absorber during transurethral surgery of the prostate. The gases were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry equipped with a purge and trap sample injector. RESULTS: The gas produced during TURVP contained propylene, allene, isobutylene, 1,3-butadiene, vinyl acetylene, mercaptomethane, ethyl acetylene, diacetylene, 1-pentene, ethanol, piperylene, propenylacetylene, 1,4-pentadiene, cyclopentadiene, acrylnitrile, and butyrolacton. The types and amount of gas produced during HPS laser prostatectomy were fewer and smaller than during TURVP. However, 1,3-butadiene, a well-known human carcinogen, was also generated by HPS laser prostatectomy. HPS laser prostatectomy with saline produced a greater amount and number of gases than HPS laser prostatectomy with Urosol. CONCLUSION: The surgical smoke produced from TURVP and HPS laser prostatectomy contains potentially harmful chemical compounds, although HPS laser prostatectomy produced less surgical smoke than TURVP. Urosol produced fewer types and a smaller amount of gas than normal saline during HPS laser prostatectomy.


Asunto(s)
Alquenos/análisis , Gases/química , Terapia por Láser , Prostatectomía/métodos , Humo , Resección Transuretral de la Próstata , Anciano , Butadienos/análisis , Ciclopentanos/análisis , Etanol/análisis , Cromatografía de Gases y Espectrometría de Masas , Sustancias Peligrosas/análisis , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
10.
J AOAC Int ; 95(6): 1614-7, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23451376

RESUMEN

Zingiber cassumunar (Zingiberaceae) has been widely used as a traditional medicine in southeast Asia, especially Thailand, for treatment of asthma, inflammation, and joint pain. (E)-4-(3,4-dimethoxyphenyl)butadiene, or DMPBD, a major component in the rhizome, has been reported to be an active anti-inflammatory agent. This research developed a TLC-densitometry method for the simultaneous quantification of DMPBD in the rhizome extracts of four varieties of Z. cassumunar. DMPBD (dimethoxyphenylbutadiene) was found in the range of 0.90 +/- 0.01 to 1.61 +/- 0.05% (w/w). [corrected] The method was validated for linearity, precision, accuracy, robustness, LOD, and LOQ. The linearity was indicated by a good regression coefficient 0.9940 and covered the range of 130 to 703 ng/band. Intraday and interday precision (RSD) were less than 2%. Accuracy of the method was evaluated by a recovery study conducted at three different levels; the average recovery was 103.1%. The LOD and LOQ were 10 and 40 ng, respectively. The proposed TLC-densitometry method was simple, precise, specific, sensitive, and inexpensive. This method can be used for routine QC of raw materials of Z. cassumunar rhizomes, extracts, and its products, especially Prasaplai, a Thai traditional medicine for relieving dysmenorrhea.


Asunto(s)
Butadienos/análisis , Rizoma/química , Zingiberaceae/química , Cromatografía en Capa Delgada , Densitometría , Indicadores y Reactivos , Límite de Detección , Espectroscopía de Resonancia Magnética , Medicina Tradicional , Extractos Vegetales/análisis , Estándares de Referencia , Reproducibilidad de los Resultados , Soluciones , Tailandia
11.
Huan Jing Ke Xue ; 31(8): 1897-903, 2010 Aug.
Artículo en Chino | MEDLINE | ID: mdl-21090311

RESUMEN

Biodegradabilities of several hydrocarbon biomarker groups, including isoprene, hopanes and steranes in a medium-crude oil BZ34-1 and a heavy-crude oil SZ36-1 from offshore, were determined under laboratory conditions. The results of GC-MS analysis showed that isoprene biomarkers such as pristane and phytane in both crude oils degraded obviously in 60-day experiment period. The degradation ratios of pristane and phytane in the medium-crude oil BZ34-1 reached 20.2% and 15.0%, respectively; while those in the heavy-crude oil SZ36-1 reached 95.6% and 75.4%, respectively. Pristane and phytane in the heavy-crude oil SZ36-1 were degraded in the early period of biodegradation, but these two biomarkers in the medium-crude oil BZ34-1 were degraded in middle and late biodegradation phases. However, hopanes and steranes in the both oils were not biodegraded obviously during the whole period. These results indicated that pristane and phytane could be used to evaluate bioremediation efficiency in the early biodegradation phase for light or medium oils, while hopanes and steranes could be used to evaluate bioremediation efficiency within the whole given experiment process.


Asunto(s)
Hidrocarburos/metabolismo , Petróleo/metabolismo , Microbiología del Suelo , Triterpenos/análisis , Biodegradación Ambiental , Biomarcadores/análisis , Biomarcadores/metabolismo , Butadienos/análisis , Butadienos/metabolismo , Hemiterpenos/análisis , Hemiterpenos/metabolismo , Hidrocarburos/aislamiento & purificación , Pentanos/análisis , Pentanos/metabolismo , Contaminantes del Suelo/aislamiento & purificación , Contaminantes del Suelo/metabolismo , Terpenos/análisis , Terpenos/metabolismo , Triterpenos/metabolismo
12.
Int J Urol ; 17(11): 944-9, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20880073

RESUMEN

OBJECTIVE: To determine the chemical composition of surgical smoke produced during transurethral resection of the prostate (TURP) and vaporization. METHODS: A total of 12 smoke samples were collected from a continuous irrigation suction drainage system to a Tenax absorber at a 0.05L/min flow rate during TURP and vaporization. The gases were quantitatively and qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS) equipped with a purge and trap sample injector. RESULTS: The main chemical constituents of surgical smoke produced during TURP and vaporization include propylene, allene, isobutylene, 1,3-butadiene, vinyl acetylene, mecaptomethane, ethyl acetylene, diacetylene, 1-pentene, EtOH, piperylene, propenylacetylene, 1,4-pentadiene, cyclopentadiene, acrylnitrile and butyrolactone. Three of the constituents are very toxic and carcinogenic (1,3-butadiene, vinyl acetylene and acrylonitrile). The amount (mean±standard deviation) of chemical components in the 45L of gas and room air mixture produced during TURP and vaporization were as follows: propylene, 0.80±0.52mg; isobutylene, 212.85±75.65mg; 1,3-butadiene, 0.93±0.34mg; ethyl acetylene, 0.09±0.05mg; 1-pentene, 6.75±1.62mg; 1,4-pentadiene, 0.06±0.02mg; and acrylonitrile, 1.62±1.19mg. CONCLUSIONS: Three of the toxic gases generated during TURP and vaporization are carcinogens (1,3-butadiene, vinyl acetylene and acrylonitrile). Therefore, higher quality filter masks, smoke evacuation devices and/or smoke filters should be developed for the safety of the operating room personnel and patients during TURP and vaporization.


Asunto(s)
Carcinógenos/análisis , Gases/análisis , Sustancias Peligrosas/análisis , Exposición Profesional/análisis , Hiperplasia Prostática/cirugía , Humo/análisis , Resección Transuretral de la Próstata/efectos adversos , Anciano , Alquenos/análisis , Butadienos/análisis , Estudios de Cohortes , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Salud Laboral , Estudios Prospectivos , Hiperplasia Prostática/diagnóstico , Medición de Riesgo , Resección Transuretral de la Próstata/métodos , Volatilización
13.
Proc Natl Acad Sci U S A ; 106(44): 18447-51, 2009 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-19841269

RESUMEN

More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly" fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O(3)), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O(3) concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O(3) concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.


Asunto(s)
Agricultura , Contaminación del Aire/análisis , Arecaceae/fisiología , Nitrógeno/análisis , Ozono/análisis , Aceites de Plantas/análisis , Clima Tropical , Aeronaves , Butadienos/análisis , Geografía , Hemiterpenos/análisis , Monoterpenos/análisis , Óxido Nítrico/análisis , Dióxido de Nitrógeno/análisis , Aceite de Palma , Pentanos/análisis , Ácido Peracético/análogos & derivados , Ácido Peracético/análisis , Factores de Tiempo
14.
Anal Chem ; 73(19): 4729-35, 2001 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-11605854

RESUMEN

A procedure to monitor BVOC emitted by living plants using SPME technique is presented. For this purpose, a glass sampling chamber was designed. This device was employed for the characterization of biogenic volatile compounds emitted by leaves of Eucalyptus citriodora. After extraction with SPME fibers coated with PDMS/ DVB, it was possible to identify or detect 33 compounds emitted by this plant. A semiquantitative approach was applied to monitor the behavior of the emitted BVOC during 9 days. Circadian profiles of the variation in the concentration of isoprene were plotted. Using diffusion-based SPME quantitation, a recently introduced analytical approach, with extraction times as short as 15 s, it was possible to quantify subparts-per-billion amounts of isoprene emitted by this plant.


Asunto(s)
Eucalyptus/metabolismo , Hemiterpenos , Compuestos Orgánicos/metabolismo , Pentanos , Plantas Medicinales , Butadienos/análisis , Butadienos/metabolismo , Técnicas de Química Analítica/métodos , Cromatografía de Gases/métodos , Ritmo Circadiano , Compuestos Orgánicos/análisis , Volatilización
15.
J Chromatogr Sci ; 28(5): 230-5, 1990 May.
Artículo en Inglés | MEDLINE | ID: mdl-1704381

RESUMEN

A method for the quantitative analysis of individual hydrocarbons in the C1-C8 range emitted in engine exhaust gases is described. The procedure provides base-line or near base-line resolution of C4 components including 1,3-butadiene. With a run time of less than 50 min, the light aromatics (benzene, toluene, ethyl benzene, p- and m-xylene, and o-xylene) are resolved during the same analysis as aliphatic hydrocarbons in the C1-C8 range. It is shown that typical 1,3-butadiene levels in engine exhaust are about 5 ppm at each of two engine conditions. Aromatic hydrocarbon levels show a dependence on engine operating conditions, benzene being about 20 ppm at high speed and about 40 ppm at idle.


Asunto(s)
Butadienos/análisis , Mutágenos/análisis , Emisiones de Vehículos/análisis , Óxido de Aluminio , Cromatografía , Dióxido de Silicio
16.
J Assoc Off Anal Chem ; 70(1): 18-21, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3558271

RESUMEN

A headspace gas chromatographic procedure has been developed for the determination of 1,3-butadiene in rubber-modified plastics and in some foods. Polymer solutions or foods are equilibrated in sealed vials at 90 degrees C, and headspace samples are injected into a gas chromatograph. 1,3-Butadiene residues are measured using a flame ionization detector and are quantitated by the method of standard additions or an external calibration curve. Refrigerator tubs, vegetable oil bottles, chewing gum, and foods in contact with this type of packaging were analyzed. Limits of quantitation varied with the matrix, ranging from 2 ng/g (ppb) in chewing gum to 20 ng/g in polymers. 1,3-Butadiene was found in one polymer at 53 ng/g with an 8% coefficient of variation. The procedure yields "apparent" trace levels of 1,3-butadiene, and confirmation by a complementary technique is required.


Asunto(s)
Butadienos/análisis , Análisis de los Alimentos , Plásticos/análisis , Cromatografía de Gases , Indicadores y Reactivos , Aceite de Oliva , Aceites de Plantas/análisis , Yogur/análisis
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