Monofluoroacetate (MFA) is a potent toxin that occurs in over 50 plant species in Africa, Australia, and South America and is responsible for significant livestock deaths in these regions. A gas chromatography-mass spectrometry (GC-MS) method for the analysis of MFA in plants based on the derivatization of MFA with n-propanol in the presence of sulfuric acid to form propyl fluoroacetate was developed. This method compared favorably to a currently employed high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for the analysis of MFA in plants. The GC-MS method was applied to the analysis of MFA in herbarium specimens of Fridericia elegans, Niedenzuella stannea, N. multiglandulosa, N. acutifolia, and Aenigmatanthera lasiandra. This is the first report of MFA being detected in F. elegans, N. multiglandulosa, N. acutifolia, and A. lasiandra, some of which have been reported to cause sudden death or that are toxic to livestock.

ABSTRACT. Mangifera indica is widely found in Brazil, and its leaves are used as an anti-inflammatory agent in folk medicine. The aim of this study is to perform composition analysis of essential oils from the M. indica varieties, espada (EOMIL1) and coração de boi (EOMIL2), and confirm their anti-inflammatory properties. Twentythree volatile compounds were identified via gas chromatographymass spectrometry (GC-MS) in two essential oils from the leaves. Paw edema and myeloperoxidase (MPO) activity were evaluated using the carrageenan-induced paw model, while leukocyte migration was analyzed using the pleurisy model. At oral doses of 100 and 300 mg/kg, the essential oils significantly reduced edema formation and the increase in MPO activity induced by carrageenan in rat paws. For a dose of 300 mg/kg EOMIL1, 62 ± 8% inhibition of edema was observed, while EOMIL2 led to 51 ± 7% inhibition of edema. At a dose of 100 mg/kg, the inhibition was 54 ± 9% for EOMIL1 and 37 ± 7% for EOMIL2. EOMIL1 and EOMIL2 significantly reduced MPO activity at doses of 100 mg/kg (47 ± 5 and 23 ± 8%, respectively) and 300 mg/kg (50 ± 9 and 31 ± 7%, respectively). In the pleurisy model, inhibitions were also observed for EOMIL1 and EOMIL2 in the leukocyte migration test. The results of the present study show that essential oils from M. indica differ in chemical composition and anti-inflammatory activity in rats.

A headspace solid-phase microextraction (HS-SPME) procedure that employs a PDMS/DVB fiber was developed for the analysis of gas-phase polycyclic aromatic hydrocarbons (PAHs) collected in polyurethane foam (PUF) by gas chromatography (GC) mass spectrometry. The method exhibited good linearity (R (2) > 0.99) and repeatability (4.9-25 %) as well as an impressive detection limit that ranged from 1.1 to 3.3 ng. Twenty-two air samples were collected by high-volume samplers from January to November 2007 in a semiurban area of Dourados (Brazil) and were analyzed for their content of total suspended particulates and PAHs. The PAHs were extracted from the PUF samples using the developed procedure (HS-SPME), and PAHs adsorbed on particulate matter were extracted with dichloromethane/methanol (4:1 [v/v]) in an ultrasonic bath. The values of the total daily concentrations of 16 PAHs determined in the samples ranged from 0.375 to 8.407 ng m(-3). In addition, diagnostic ratios were calculated, showing that the PAHs in the atmosphere at the sampling site originated predominantly from vehicle emissions and the combustion of grass and wood. Hierarchical cluster analysis and principal component analysis were performed as well, the results of which indicated (1) the same sources of PAH identified by the diagnostic ratios and (2) that the sampling days could be categorized into three groups depending on the atmospheric conditions. GC retention indices were also used to identify PAHs, biphenyl (phenylbenzene), and heterocyclic organic compounds (benzofurans) in some of the samples.

Volatile oils of Microlobius foetidus were used for the evaluation of mortality, trypsin, chymotrypsin and acetylcholine inhibition and Aedes aegypti morphology. Bioassays were made with different concentrations (25, 50 and 100 μg/ml) and alterations in the gut of 4th stage larvae were observed. Volatile oils affected larvae in all stages, with 100% mortality for the 100 μg/ml concentration (LD 50 >33.02). The acute toxic unit (2.7 μg/ml), chronic toxic unit (32.68 μg/ml) and toxic load (2.7 μg/ml) confirm the sensibility of the 4th stage larvae. These larvae and 3rd presented a lesser trypsin (0.176 μmol/min), chymotrypsin (0.110 μmol/min) and acetylcholinesterase (0.172 μmol/min) synthesis. Larvae of the 4th stage also had their internal morphology observed, and the main alterations were discontinuity of the peritrophic epithelium, thickening of the peritrophic membrane, decrease/increase of the subjacent epithelium and decrease of endoperitrophic space were observed in the mid gut. The results show the repellent activity of the volatile oils of M. foetidus, with a retardation of overall growth, that are associated with the inhibition of the trypsin and chymotrypsin synthesis. Mortality and enzymatic inhibition in all developmental stages confirm the insecticide potential of M. foetidus.