2017年6月9日

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Date: 16.00am-18.00am, Friday, 9 June 2017

Place: 5F, Conference room, Main Chemistry Build.
Speaker1: Weibin Gui
Speaker2: Hideyuki Obayashi

日　時：2017年6月9日（金）16:00～18:00
場　所： 化学本館5階会議室
講演者1：桂維彬
講演者2: 大林秀行

–Speaker1–
Title: Pressure-induced Phase Transition of Alkali Hydrogen Carbonates
Abstract:
Alkali metal hydrogen carbonates belong to series of inorganic substances that contain HCO3- as anions and alkali metal (such as Na, K, Rb and Cs) as cations. In KHCO3, RbHCO3 and CsHCO3, two (HCO3-) groups bonded by two H bonds form (HCO3-)2 dimers and compose basis of their crystal structure (Thomas 1974; Kim 1969; Kaduk 1993). Among them, the crystal structure of KHCO3 and RbHCO3 is similar, while that of CsHCO3 is a little different in the orientation of (HCO3-)2 dimers .
Previous studies showed that KHCO3 has an obvious phase transition at around 2.8 GPa (Nagai et al. 2002). Interestingly, the crystal structure of this high-pressure phase is like the ambient phase of CsHCO3 (Komatsu et al. 2007 , Allan et al. 2007). Since there is no previous report on pressure-induced phase transition of RbHCO3 and CsHCO3, this study proposes to investigate their high-pressure behaviors.
Based on powder X-ray diffraction (XRD) and Raman spectroscopy measurements, it was confirmed that RbHCO3 has a high-pressure phase below 0.5 GPa, and its crystal structure should be like the high-pressure phase of KHCO3, as well as the ambient phase of CsHCO3. In CsHCO3, no obvious phase transition was observed up to 5 GPa. In the seminar, the phase transition pressure, the crystal structures and the compressibility of RbHCO3 will be discussed.

–Speaker2–
Title: Quantitative analysis of hazardous elements in plastics using laser ablation-ICPMS
タイトル： レーザーアブレーション−ICPMSによるプラスチック中の有害元素の定量分析
Abstract:
RoHS指令(Restrictions of the use of certain Hazardous Substances in electrical and electronics equipment、日本語では、電気・ 電子機器中の特定有害物質の使用禁止令)により、この規制の基準を満たさない電子機器をEUへ輸出することは禁止されている。六価クロム、水銀、鉛はそれぞれ1,000ppm以下、カドミウムは100ppm以下でなけらばならない。これらの元素の定量にはスクリーニングとして蛍光X線分析法、精密分析としてICP発光分析法、ICP質量分析法、原子吸光分析法などが用いられている。しかし、精密分析をする際は試料を酸で溶解しなければならないという問題がある。本発表ではレーザーアブレーション−ICPMSによるPP樹脂の定量分析の結果を報告する。