PNNL

Abstract

The goal of this research is to develop highly selective sorbents that allow collection of a relatively pure analyte fraction during the sampling step. The high fraction purity allows development of simplified field-portable instrumentation that is capable of high integrity analysis at trace concentrations. Our FY 2005 research emphasized two molecularly imprinted polymer (MIP) areas. The first activities completed studies of MIPs specific toward volatile signatures, whereas the second developed MIPs toward nonvolatile signatures. Our previous work demonstrated highly selective MIP-based capture of targeted volatile signatures from complex samples with near quantitative recovery. Additional FY 2005 studies demonstrated the expected sorbent cross reactivity and verified superior matrix discrimination on MIPs compared to traditional normal-phase sorbents. This work was published in Journal of Separation Science in May 2005 (included as an appendix in this report). The second area of research synthesized and characterized MIPs specific toward nonvolatile half-acid phosphate or methylphosphonate ester signature compounds. These sorbents form the core of a MIP-based trace enrichment instrument described in our FY 2004 Final Report. FY 2005 studies definitively verified these MIPs selectively captured their targets relative to a nonimprinted control sobent. Extensive cross reactivity studies were also conducted with chemically related compounds. Encouraging results demonstrated high affinity and selectivity of these MIPs; a result that suggests these sorbents will be highly effective in the MIP-based trace enrichment system. Matrix discrimination capabilities of the MIPs should be tested before characterizing the trace enrichment system. Recommendations for future research that addresses MIP studies for both volatile and nonvolatile signatures is provided.