Xieite,a new mineral of high-pressure FeCr_2O_4 polymorph

Xieite,a new mineral,occurs in the shock vein of the Suizhou meteorite.The mineral has an ortho-rhombic structure and its space group is Bbmm.The cell parameters are a = 9.462(6),b = 9.562(9),c = 2.916(1).The crystal-chemical formula is(Fe0.87Mg0.13Mn0.01)1.01(Cr1.62Al0.25Ti0.08V0.02)1.97O4,or simply formula FeCr2O4.Stronger X-ray diffraction lines are [d(),I/Io]:(2.675,100),(2.389,20),(2.089,10),(1.953,90),(1.566,60),(1.439,15),(1.425,15),(1.337,40).Xieite is a high pressure polymorph of FeCr2O4 and formed by solid-state transformation of chromite under shock-induced high pressure and tem-perature,in association with other high-pressure minerals including ringwoodite,majorite,lingunite and tuite.The P-T condition for the formation of xieite is estimated to be 18―23 GPa and 1800―1950℃,respectively.Xieite has recently been approved by the Commission on New Minerals,Nomenclature and Classification of the International Mineralogical Association(IMA 2007-056).The mineral name,xieite,is named after Xiande Xie.

GC测定克痢痧胶囊中的冰片、甲基丁香酚和丁香酚的含量

目的采用GC测定克痢痧胶囊中的冰片、甲基丁香酚和丁香酚的含量。方法采用GC直接进样,色谱柱为Agilent HP-INNOWAX毛细管柱,检测器为氢火焰离子化检测器,温度为250℃,采用程序升温,进样口温度为210℃;流速为1.2 mL·min^(-1),分流比为15︰1,进样量为1μL。结果冰片、甲基丁香酚和丁香酚的线性范围分别是48.59～728.88μg·mL^(-1)(r=0.999);4.29～64.39μg·mL^(-1)(r=0.999)和31.83～477.48μg·mL^(-1)(r=0.999),精密度、重复性和稳定性试验的RSD均≤2.17%,平均加样回收率分别是98.69%(RSD=0.3%),93.10%(RSD=1.6%)和99.41%(RSD=0.5%)。结论本方法操作简单、快速、准确性和重复性好,可用于克痢痧胶囊的质量控制。