Adsorption and catalytic decomposition of 4-nitrobenzenesulphonylmethylcarbamate (herbicide Nisulam) on Upton, Wyoming, bentonite saturated with different cations was studied using thin-layer chromatography and infrared spectroscopy. Nisulam is adsorbed at room temperature by coordination through the NO~ group to the exchange cation regardless of the cation's nature. On moderate heating (75~176 this molecule decomposes to 4-nitrobenzenesulphonamide whereas a similar compound (herbicide Asulam) containing the NHz functional group instead of NOz is adsorbed by protonation at room temperature and decomposes into different products. For cations having a high polarizing power, a coordination bond between the Asulam molecule's C=O group and the exchange cation is established, and the molecule decomposes to sulphanilic and carbamic acid. In contrast, for cations having a low polarizing power there is no coordination, and the molecule decomposes mainly into sulphanilamide. Nisulam's coordination to the exchange cation through the NO2 group instead of C=O is ascribed to inductive and conjugation effects, typical of the nitro group.

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È stata analizzata la composizione chimica dell'olio essenziale di foglia di Myrtus communis L. di varie provenienze della Toscana; Cecina (LI)-Alberese (GR)-Liguria: Monte Marcello (SP)-Sardegna: Posada, Ispingoli, Oliena e Monte Pizzinnu (NU). L'olio essenziale è stato estratto per distillazione in corrente di vapore e la composizione chimica è stata determinata mediante gascromatografia capillare (GC) abbinata alla spettrometria di massa (GC/MS). I singoli costituenti degli olii essenziali sono stati identificati per confronto con i tempi di ritenzione di campioni autentici e confermati per mezzo della spettrometria di massa. Variazioni quali-quantitative sono state osservate tra gli olii essenziali estratti dalle foglie dei campioni delle varie provenienze. I maggiori componenti identificati sono stati α-pinene, 1,8 cineolo, limonene, linalolo, α-terpineolo, geranil acetato e geraniolo. Il Mirtenil acetato è stato individuato nei campioni toscani (14.60 e 90.84 mg/g di olio), ma non in quello ligure ed in quelli sardi. La resa in olio risulta essere la più elevata nei campioni sardi, mentre era simile in quelli toscani ed in quello ligure.

The chemical composition of the essential oils, obtained by separate distillation of the leaves, branches and fruits of Pistacia lentiscus from Tuscany (Italy), was analyzed and identified by GC and GC/MS. The leaf oil contained α-pinene (16.1-25.3%), limonene (6.6-12.3%), terpinen-4-ol (7.6-12.7%) and germacrene D (9.6-14.3%) as major components. The branch oil contained α-pinene (34.4-46.2%), myrcene (6.3-11.6%) and limonene (8.1-13.0%), while the fruit oil contained α-pinene (7.5-11.2%), myrcene (68.2-71.0%) and limonene (9.6-19.7%) as major constituents.Little differences in composition were found between samples collected in different seasons and years, while epigenetic variations were observed for samples of oils from different sources.