Spatial distribution of SiCln （n=O-2） in SICl4 plasma measured by mass spectroscopy

For a better understanding of the deposition mechanism of thin films in SiCl4 source gas, we have measured the spatial distributions of SiCln （n=0-2） radicals in SICl4 radio frequency glow discharge plasma utilizing a mass spectrometer equipped with a movable gas sampling apparatus. The experimental results demonstrate that the relative densities of SiCln （n=0-2） radicals have peak values at the position of 10 mm above the powered electrode along the axial direction; the relative densities of the Si and SiCIn （n=1, 2） radicals have peak values at the positions of 27mm and 7 mm away from the axis along the radial direction, respectively. Generally speaking, in the whole SICl4 plasma bulk region, the relative density of Si is one order of magnitude higher than that of SICl, and the relative density of SiCl is several times higher than that of SICl2. This reveals that Si and SiCl may be the primary growth precursors in forming thin films.

柱前衍生HPLC分析石榴皮中的脂肪酸

目的采用HPLC—FLD—MS法分析石榴皮中的脂肪酸。方法用2-（11H-苯[a]咔唑）乙基对甲苯磺酸酯作为柱前荧光衍生试剂，选择Hypersil BDS C8液相色谱柱（200mm×4．6mm，5μm），流动相A、B分别为100％、5％乙腈，流速1．0mL·min^-1，柱温35℃，进样量10止，检测波长荧光激发λex279nm、发射λem380nm。结果所有脂肪酸衍生物均有较好的线性、灵敏度、回收率和精密度，r均大于0．9991，检测限为0．38～1．95ng·mL^-1。结论石榴皮中富含饱和与不饱和脂肪酸，尤其是油酸和棕榈酸。该方法可为石榴皮的药理应用研究和质量控制提供依据。