In this paper, a polypropylene frit with porous network structure and high area-to-thickness ratio (4.8 mm diameter, 1.6 mm thickness, 20 mm pore size) was utilized as a mould of monolith. Poly(methacrylic acid-ethlyene glycol dimethacrylate) (MAA-EGDMA) monolith was in situ synthesized in the micro-channel of frit by photopolymerization. A monolith frit-based solid-phase microextraction method (SPME) was developed for the determination of hexanal and heptanal in serum samples by combining with high-performance liquid chromatography. 2,4-Dinitrophenylhydrazine (DNPH) as the derivatizing reagent was absorbed on a monolith frit, then its derivatization reaction with aldehydes and the absorption of formed hydrazones on the monolith disk occurred simultaneously. The condition parameters for polymerization, derivatization and extraction were optimized systematically. Under the optimum conditions, rigid structure, low back-pressure and high column capacity were achieved for the monolith frit. The limits of detection for hexanal and heptanal were 1.86 and 1.38 nmol/L, respectively. The inter- and intra-day relative standard deviations were less than 7.7% (n = 6). This method was applied successfully to aldehydes analysis in human serum samples. The method possesses advantages such as simplicity, efficiency, low cost and good biocompatibility. It provides an alternative approach for quantification of aldehydes in complex biological samples.

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The formation of the metastable bcc solid solution and the amorphous phase during interfacial reaction of elemental multilayers has been studied using X-ray diffraction. Different kinds of interfaces have been synthesized in order to investigate the influence of the interfacial structure on phase evolution during annealing. The amorphization is found to be dependent on the structure of the interface and the results are discussed in terms of the kinetics and thermodynamics of the Ti-Fe system which has been calculated by the CALPHAD method.

Ti/Fe bilayers are deposited on Si02 substrate in ultra-high-vacuum environment ( i0 Torr) in different sequence: Si02/Fe(200A)/Ti(300A) and Si02/Ti(300A)/Fe(200A). The interfaces of the films and their evolution at various annealing stages are studied by X-ray reflectivity measurements using high resolution triple-crystal X-ray cliffractometer. The study shows that a different sequence of deposition results in different microstructure and affects subsequent evolution of the interfaces. It is also noticed that the annealed films are contaminated by the oxygen. Electron density profiles for the structures are obtained by nonlinear least square fits to the reflectivity curves.