Cs+ Speciation on Soil Particles by TOF-SIMS Imaging

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• 作者：Gary S. Groenewold ; Jani C. Ingram ; Travis McLing ; Anita K. Gianotto ; and Recep Avci
• 刊名：Analytical Chemistry
• 出版年：1998
• 出版时间：February 1, 1998
• 年：1998
• 卷：70
• 期：3
• 页码：534 - 539
• 全文大小：100K
• 年卷期：v.70,no.3(February 1, 1998)
• ISSN：1520-6882

文摘

Soil particles exposed to CsI solutions were analyzed byimaging time-of-flight secondary ion mass spectrometryand also by scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). The results showedthat Cs⁺ could be detected and imaged on the surfaceofthe soil particles readily at concentrations down to 160ppm, which corresponds to 0.04 monolayer. Imagingrevealed that most of the soil surface consisted of aluminosilicate material. However, some of the surface wasmore quartzic in composition, primarily SiO₂ withlittleAl. It was observed that adsorbed Cs⁺ was associatedwiththe presence of Al on the surface of the soil particles.Incontrast, in high SiO₂ areas of the soil particle wherelittleAl was observed, little adsorbed Cs⁺ was observed onthesurface of the soil particle. Using EDS, Cs⁺ wasobservedonly in the most concentrated Cs⁺-soil system, andCs⁺was clearly correlated with the presence of Al and I.Theseresults are interpreted in terms of multiple layers of CsIforming over areas of the soil surface that contain substantial Al. These observations are consistent withthehypothesis that the insertion of Al into the SiO₂latticeresults in the formation of anionic sites, which are thencapable of binding cations.