Croce Alessandro, Allegrina Mario, Rinaudo Caterina, Gaudino Giovanni, Yang Haining, Carbone Michele
1Department of Science and Technological Innovation,Università del Piemonte Orientale "Amedeo Avogadro",Viale Teresa Michel 11,15121 Alessandria,Italy.
2University of Hawai'i Cancer Center,University of Hawai'i,96813 Honolulu,HI,USA.
Microsc Microanal. 2015 Oct;21(5):1341-7. doi: 10.1017/S1431927615014762. Epub 2015 Aug 19.
Erionite samples from Rome, Oregon (USA) and Karlik, Cappadocia (Turkey) were analyzed by environmental scanning electron microscopy (E-SEM) coupled with energy-dispersive spectroscopy (EDS) to verify the chemical composition of this mineral phase, and the presence of iron in particular. By means of backscattered electron images, a large number of particles/grains were observed on the surface of the erionite fibers from both locations. The particles were found to be micrometric on samples from Rome and submicrometric on samples from Karlik, and always lighter than the hosting crystal in appearance. In different areas of the same fiber or bundle of fibers, several EDS spectra were recorded. Iron was detected only when a light particle was lying in the path of the electron beam. Iron was never identified in the EDS spectra acquired on the flat erionite surface. The results from E-SEM/EDS were confirmed by micro-Raman spectroscopy, showing bands ascribing to hematite—Fe2O3, goethite—FeO(OH), or jarosite—KFe3(3+)(SO4)2(OH)6 when the laser beam was addressed on the light particles observed on the fiber surface. The evidence that iron is on the surface of erionite fibers, rather than being part of the crystalline structure, may be relevant for the carcinogenic potential of these fibers.
对来自美国俄勒冈州罗马和土耳其卡帕多西亚的卡尔利克的毛沸石样本进行了环境扫描电子显微镜（E-SEM）结合能量色散光谱（EDS）分析，以验证该矿物相的化学成分，特别是铁的存在情况。通过背散射电子图像，在来自这两个地点的毛沸石纤维表面观察到大量颗粒/晶粒。发现来自罗马的样本上的颗粒为微米级，而来自卡尔利克的样本上的颗粒为亚微米级，且在外观上总是比主体晶体轻。在同一根纤维或一束纤维的不同区域记录了多个EDS光谱。仅当一个轻质颗粒位于电子束路径上时才检测到铁。在平整的毛沸石表面获取的EDS光谱中从未鉴定出铁。E-SEM/EDS的结果通过显微拉曼光谱得到证实，当激光束照射在纤维表面观察到的轻质颗粒上时，显示出归因于赤铁矿—Fe2O3、针铁矿—FeO(OH)或黄钾铁矾—KFe3(3+)(SO4)2(OH)6的谱带。铁位于毛沸石纤维表面而非晶体结构一部分的证据，可能与这些纤维的致癌潜力相关。
