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A novel in-needle sample preparation device has been developed for the determination of volatile aldehydes in gaseous samples. The needle device is designed for the gas chromatographic (GC) analysis of aldehydes and ketones commonly found in typical in-house environments. In order to prepare the extraction device, a bundle of polymer-coated filaments was longitudinally packed into a specially designed needle. Derivatization reactions were prompted by 2,4-dinitrophenylhydrazine (NDPH) included in the needle, and so the aldehydes and ketones were derivatized to the corresponding hydrazones and extracted with the extraction needle. A reproducible extraction needle preparation process was established, along with a repeatable derivatization/extraction process that ensures the successful determination of aldehydes. The storage performance of the extraction needle was also evaluated at room temperature for three days. The results demonstrate the successful application of the fiber-packed extraction device to the preparation of a gaseous sample of aldehydes, and the future possibility of applying the extraction device to the analysis of in-house environments.

Resistivities of single-crystalline as well as poly-crystalline samples of CeOBiS2 without fluorine doping were measured at temperatures down to 0.13 K, and were compared with those of poly-crystalline LaOBiS2 and PrOBiS2. Both poly-crystalline and single-crystalline CeOBiS2 exhibited zero resistivity below 1.2 K while poly-crystalline LaOBiS2 and PrOBiS2 did not show zero resistivity down to 0.13 K. Superconducting transition temperature of CeOBiS2 was reduced by increasing the applied current density. The superconductivity of CeOBiS2 without chemical doping is likely triggered by the carriers induced by the valence fluctuation between Ce3+ and Ce4+.Comment: 19 pages, 5 figures in Solid State Communications 201