The proposed research will lead to the development of a hardware item, to be inserted into the inlet of a gas chromatograph (GC) that will catalyze """"""""on-line"""""""" derivatizations of injected analytes inside the hot GC injection port. Such on-line derivatizations are now being done with the use of conventional glass GC inlet liners and other highly inert materials that are intended to discourage, rather than promote, inside-the-inlet chemical reactions. It is hypothesized that use of a suitable solid heterogeneous catalyst inside the GC inlet will significantly reduce the temperatures and/or reagent concentrations needed to drive many on-line derivatizations to completion. This product will be especially applicable to trace-level determinations of relatively low-molecular-weight compounds that lack the required volatility, stability, detectability, or intrinsic chromatographability to be effectively determined by GC instrumentation without the aid of derivatization. Such compounds may include amino acids, fatty acids, nucleosides, sugars, steroids, drugs, surfactants, vitamins, pollutants, toxins, metabolites, degradation products, impurities, and so on. The Phase I specific aims are: (1) to find several chemically diverse derivatization reactions that are clearly inefficient in an on-line mode under """"""""baseline"""""""" conditions, i.e., in a conventionally configured GC inlet in the absence of a catalyst, and that can therefore serve effectively as model reactions during Phase I and Phase II evaluations of candidate catalysts; and (2) to evaluate an array of candidate catalysts with the selected model reactions in a GC inlet and to establish proof-of-principle by identifying at least 1 effective catalyst that clearly promotes at least 1 of the model derivatizations. The main goal of Phase II will be to find an optimally effective catalyst or suite of catalysts and to characterize the conditions under which the identified catalyst(s) can and cannot be expected to perform well.
The proposed GC inlet accessory is expected to increase the usefulness of the GC analysis technique in a variety of clinical, industrial, academic, government, and other biomedical laboratory settings. Hence, it should lead to significant improvements in the speed, sensitivity, selectivity, accuracy, cost, and/or simplicity of diverse biomedically significant chemical analyses. For this reason, numerous public-health-related programs, functions, and objectives should benefit from this broadly enabling technology. ? ? ?
|Fowler, William K; Gamble, Kelly J; Wright, Amber R (2010) Catalytically-promoted analyte derivatization inside a gas chromatographic inlet. J Chromatogr Sci 48:466-72|