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 and structural characteristics of clays from samples of eight Tuscan soils were investigated. Using simple selective dissolution method (successive boiling in 1 N HCl and 0"5 N NaOH) it was possible to distinguish two types of low charge dioctahedral vermiculite; one easily HC1 soluble the other practically insoluble.

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.

A.U. 5c C I I I I 350 450 550 650 (nrnl Figure 2 PA spectra of pure picramidopropyl silica (sample 11) and the same sorbent with adsorbed anthracene.sample (I). One can conclude that Sample I contains species absorbing in the 450-750 nm region and that the reaction of NH2silica with picryl chloride is less selective than the other procedures.The increased absorption around 500 nm may be caused by a charge-transfer band arrising, e.g., from interactions of unreacted NH2-groups with bonded picramide ligands; a red complex formed from N-propyl picramide and n-propylamine was studied by us in dichloromethane. This interaction influences separation in charge-transfer HPLC of polycondensed aromatic hydrocarbons [4]. Also anthracene adsorbed on picramidopropyl silica causes an increase of absorption near 480 nm as shown in Figure 2. The slight color change of the original Sample II after adsorption of anthracene is in accordance with relative weakness of the chargetransfer interaction observed during chromatographic separations of polycondensed aromatic hydrocarbons on picramidopropyl silica [4].

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