A cloudy (“veiled”) extra‐virgin olive oil was stored 10 mon at room temperature and monitored at 15‐d intervals. The oil was very stable under oxidizing conditions; a slight increase in free acidity (from 0.2 to 0.3%, expressed as oleic acid), a notable rise in the amount of diacylglycerols and a minor increase in peroxide content were observed. Turbidity disappeared after a few months due to chemical bonding between a nitrogen‐containing component and the free acids that were released over time. The material in suspension, therefore, contained some chemical groups capable of acting as antioxidants.

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The lipid fraction of annatto (Bixa orellana L.) seeds was extracted with a Soxhlet apparatus with n-hexane and isolated by thin-layer chromatography. The fatty-soluble antioxidant fraction contained only tocotrienols, mainly δ-tocotrienol, but no tocopherols. The presence of tocotrienols was confirmed by gas chromatography-mass spectrometry. The quantities of δtocotrienol were 140-147 mg/100 g dry seeds and 5.2-5.5% wt/wt of lipid extract, determined by gas chromatography and high-performance liquid chromatography, respectively. Currently no vegetable species seems to contain comparable concentrations of δ-tocotrienol.

The analysis of the unsaponifiable fraction of several oil samples was performed by a new gas chromatographic technique with a polar column of high thermal stability. This column was adequate for fractionating sterols, methyl sterols and alcohols of the unsaponifiable matter, and allowed the detection of peaks usually unresolved with nonpolar columns.

A procedure for the simultaneous separation and determination of fission products (lanthanides) and actinides (Pu, Np, U, Am and Cm) is described. The method is based on the use of an anionic/cationic mixed bed chromatographic column (CS5A, Dionex), coupled on-line to an ICP-MS detector. Optimisation of the parameters was carried out with standard solutions containing actinides and lanthanides at the 50 ng ml 21 concentration level. The effects of different oxidising/reducing agents as well as different mobile phases on the intensity and position of the chromatographic peaks were investigated. The analytical procedure was validated by the use of certified materials as well as by other independent techniques. Analytical figures of merit resulting from the procedure were compared with those obtained using other commercially available ion-exchange stationary phases. The procedure developed was applied to the inventory of spent nuclear fuel samples. Detection limits of 0.25 ng ml 21 and 0.45 ng ml 21 were obtained for lanthanides and actinides, respectively. Analytical precision was typical better than 5% over seven repeated measurements.