Nanometric mixed iron-titanium oxides were prepared by mechanical milling with a view to determining their ability to act as anodic materials in lithium cells. At a TiO 2 /Fe 2 O 3 mole ratio of 0.4, a solid-state reaction occurs that leads to the formation of Fe 5 TiO 8 , which possesses a spinel-like structure; at lower ratios, however, the structure retains the hematite framework. Li/g-Fe 2 O 3 cells exhibit poor electrochemical reversibility; by contrast, Ti-containing electrodes possess improved cycling properties. Changes in the electrodes upon cycling were examined by X-ray photoelectron spectroscopy ͑XPS͒. XPS data confirm the participation of electrolyte in the electrochemical reaction and the different type of electrochemical reversibility exhibited by samples. Both processes were influenced by the presence of titanium. Titanium dioxide, in the presence of iron oxides, seems to be inactive to the electrochemical process. Based on the step potential electrochemical spectroscopy ͑SPES͒ curves and photoelectron spectra obtained, the presence of Ti increases the reversibility of the redox reactions undergone by the electrolyte during discharge/charge processes. The increased active-material/electrolyte/inactive-material interaction which is reported here offers new perspectives for the use of well-known transition oxides as anode materials in Li-ion batteries.

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An analytical procedure for the analysis of lipophilic extractives from wood and pitch deposits is described in this paper. It comprises a rapid gas chromatographic method that enables the analysis of a high number of samples in a short period of time. Short-length, high-temperature capillary columns with thin films and high temperature-programming rates were preferred for the rapid analysis of wood extractives since they enable elution and separation of compounds within a wide molecular mass range (from fatty acids to sterol esters and triglycerides) in the same chromatographic analysis in a short period of time. Several examples of analysis of extractives from pine and eucalypt woods and pitch deposits in an eucalypt kraft pulp, are shown. On the other hand, a simple fractionation method using solid-phase extraction (SPE) in aminopropyl cartridges is described for the preparative scale separation and fractionation of wood lipophilic extractives into major lipid classes. The SPE advantages include smaller sample and solvent requirements and ease of use compared to conventional solvent extraction techniques.