Two methods using headspace solid-phase microextraction and gas chromatography - mass spectrometry were developed for the determination of polycyclic aromatic hydrocarbons (PAH) and BTEX. Best results were obtained using DVB/CAR/PDMS fiber, with 10 min extraction at 25 °C and 0.15 min desorption at 260 °C (BTEX), and PDMS/DVB fiber, with 60 min extraction at 90 °C, 10% NaCl and 5 min desorption at 270 °C (PAH). LOD intervals were 3x10-2 - 5x10-2 µg L-1 (BTEX) and 1.6x10-3 - 1.4 µg L-1 (PAH). The methods were applied to forty-five groundwater samples from monitoring wells of gas stations and only benzene level exceeded the limit established by Brazilian regulations.

Neste estudo, dois tipos de pirólise líquida foram realizados, uma produzida em laboratório e outra adquirida de uma companhia que fornece produtos agrícolas. As análises foram feitas por cromatografia gasosa com detecção através de ionização de chama (GC-FID) e espectrometria de massa (GC-MS). Os correspondentes perfis para as duas amostras são discutidos. Siringol, 1,2,3-trimetoxibenzeno, 2-metoxi-4-metilfenol, o-guaiacol e 5-tert-butilpirogalol foram as substâncias mais abundantes na extração ácida (ácido pirolenhoso + alcatrão solúvel). A composição dos líquidos pirolíticos foi caracterizada principalmente por metoxifenóis (guaiacol, siringol e seus derivados), fenóis, ácidos carboxílicos (C5-C17) e em uma menor quantidade para álcoois (C5-C9), cetonas (C7-C8) e aldeídos (C5-C7). Os resultados para o fertilizante foliar mostraram a presença de alcatrão solúvel e ácido pirolenhoso.

In this study, two kinds of samples of pyrolysis liquid were analyzed, one produced at laboratory and other acquired from a company that supplies agricultural inputs. The analyses were carried out by gas chromatography with flame ionization detector (GC-FID) and mass spectrometry (GC-MS). The profiles corresponding to the two samples are discussed. Syringol, 1,2,3-trimethoxybenzene, 2-metoxy-4-methylphenol, o-guaiacol and 5-tert-butylpyrogalol were the most abundant substances in the acid extract (pyroligneous acid + soluble tar). The composition of the pyrolysis liquids was mainly characterized for methoxyphenols (guaiacol, syringol and their derivatives), phenols, carboxylic acids (C5-C17) and in a smaller amount for alcohol (C5-C9), ketones (C7-C8) and aldehydes (C5-C7). The results for the foliar fertilizer showed the presence of soluble tar and pyroligneous acid.

A method based on headspace - solid phase microextraction coupled with gas chromatography - mass spectrometry was validated for the quantitative determination of 18 organochlorine pesticides in water. For the extraction conditioning some parameters as the best type of coating fiber, time and temperature of extraction, pH and ionic strength were evaluated. The method HS-SPME/GC-MS/MS showed linear coefficient above 0.9948. The repeatability of the measurements were lower than 7.6%. Relative recoveries were between 88 and 110%. Limits of detection from 0.5 x 10-3 to 1.0 mg L-1 were obtained. A total of 31 samples were analyzed and 16 presented from 1 to 5 pesticides.

Os óleos essenciais obtidos das folhas de Campomanesia adamantium foram caracterizados através da combinação de CG-EM e índice de retenção, sendo identificado um total de 95 compostos. Na floração as substâncias majoritárias foram monoterpenos (limoneno, α-pineno e β-pineno) e durante o estágio vegetativo as substâncias majoritárias foram sesquiterpenos (biciclogermacreno e globulol). Os óleos essenciais obtidos da floração e frutificação mostraram alta atividade contra Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans e moderada contra Escherichia coli em todos os estágios. Foi avaliada a atividade antioxidante dos óleos essenciais usando o método do DPPH. O óleo essencial das 4 cidades mostrou a presença de α-pineno, β-pineno, limoneno, linalol, β-cariofileno, germacreno D e biciclogermacreno, mas a amostra da cidade de Jardim não apresentou limoneno e linalol.

The essential oils from Campomanesia adamantium (Cambess.) O. Berg leaves, collected in the reproductive (flowering and fruit-bearing) and vegetative stages, were characterized by GC-MS (Gas Chromatography-Mass Spectrometry). A total of 95 compounds of the essential oils were identified. In the reproductive stage (flowering) the major constituents were monoterpenes (limonene, α-pinene and β-pinene) while during the vegetative stage the major constituents were the sesquiterpenes (bicyclogermacrene and globulol). The essential oil of the reproductive stage shows high antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, and all show moderate activity against Escherichia coli. The essential oils were also evaluated for their radical-scavenging activity by DPPH. The chemogeographical variations of the oil composition from the four distinct localities studied all contained α-pinene, β-pinene, limonene, linalool, β-caryophyllene, germacrene D and bicyclogermacrene, however the samples from Jardim city contained neither limonene nor linalool.

Concentrations of Fe, Mn, Co, Cr, Zn and Cu were determinated using flame atomic absorption spectrometry in nine lichen species of the Sul-Mato-Grossense cerrado. The average metal ion concentrations varied in the following ranges: Fe, 248.41-1568.01; Mn, 98.50-397.33; Co, 10.08-24.81; Cr, 18.24-44.26; Zn, 14.62-34.79 and Cu, 3.23-7.57 mg kg-1. Statistical analysis (Pearson and Cluster) applied to the metal ion concentrations indicated that the accumulation of these ions can be due to several anthropogenic sources including agricultural activities, mineral exploration, biomass burning, soil mineral composition and leather tanning processes by chromium.