PNNL

Abstract

Nanostructured materials for selective collection of trace-level metals from aqueous systems A critical ability for responding to situations involving environmental contaminants is the ability to quickly identify the contaminant(s) involved and the scope of the contamination. Simple field-screening methods are needed to enable on-site, information allocation and decision making. Currently, analytical technology does not exist to allow quick, accurate, and efficient analysis. Existing field-screening methods lack the selectivity and sensitivity needed to provide key information. A large leap in performance is needed and is very unlikely to be achieved with incremental improvements in procedure, instrument design, or improved electronics. A new analytical approach is required. Deficiencies in selectivity and sensitivity can be addressed with high-performance sorbent materials capable of selectively concentrating the target analytes and removing them from the sample matrix. By concentrating and removing the target analyte, these sorbent materials provide a well-defined matrix for analysis. This chapter examines the use of nanostructured materials for the selective collection of trace-level metals from aqueous systems. The focus lies on thiol-functionalized materials. Focusing on thiol surface chemistry allows comparison of mesoporous silica, activated carbon, and superparamagnetic nanoparticles. The chapter also discusses zeolites, imprinted polymer materials, and activated carbon in general. The materials reviewed here are evaluated based on capacity, selectivity, and affinity for target analytes. Research presented here shows that correctly constructed nanostructured materials are superior to conventional sorbents.