The project focuses on seeking new chemistry among the natural defensive strategies of plants and insects in order to develop biorational methods for insect control. Thus, research is heavily focused on the analysis of micro amounts of volatile compounds from plants and insects. Currently, separations of volatile compounds by capillary gas chromatography and electron impact ionization of eluting compounds yielding interpretable fragmentation patterns is the method of choice for these studies. In addition, infochemicals involved in insect-plant interactions (i.e., defense, alarm, recruitment, host selection, repellent, attractant, communication etc.) are often present at low levels as components of a complex mixture containing numerous isomers. Thus, their characterization requires, in addition to separation and mass fragmentation, an additional discriminatory mechanism to identify isomeric compounds that cannot reliably be identified from fragmentation data alone. The ability to interface a gas-phase infra-red (IR) detector with the GC/MS instrument adds the essential capability to detect and identify many isomeric structures that are presently refractory to identification by fragmentation pattern alone. An IR interface would not only improve the identification of minute quantities of closely related analytes but do so as a part of the existing GC/MS analytical process. Capillary gas chromatography linked with Fourier transform gas-phase infrared spectroscopy and mass spectrometry meets the need for such difficult micro analyses. Because each analysis requires identification of a dozen or more compounds, searchable libraries, containing the fragmentation patterns of thousands of known compounds, are an absolute necessity. Upgrading the software data system to accommodate MS-DOS will permit access to an enormous resource base of compoundq that will vastly enhance structure characterization. Similarly, interaction with the data systems developed by colleag ues engaged in similar studies will allow sharing of information and research results. The existing GC/MS hardware has been very well maintained and is in excellent condition. However, the present data system depends entirely upon a Pascal based system which is wholly incompatible with modern data systems that utilize MS DOS exclusively. The language impasse prevents linkage with an IR interface and prevents communication with colleagues. Equally, the computer language obstacle prohibits use of the new, expanded fragmentation libraries now available. The inability to discriminate among isomers by analysis of their fragmentation patterns is very frustrating and requires time consuming analysis `y alternative techniques. The addition of an IR interface to the existing instrument will go a long way toward resolving isomeric components without additional investigative procedures. In addition to its inability to distinguish between geometric isomers of natural products such as eugenol and isoeugenol MS alone cannot differentiate between cis and trans isomers of terpenoids and related structures. On the other hand infrared spectroscopy provides very useful information for discrimination among isomeric composites. Currently, the identification of isomeric compounds through comparison of their GC retention times on a variety of phases with those of authentic standards is necessary. Gas phase infrared is often able to differentiate between isomers of related compounds and combined with mass spectroscopy will greatly facilitate identification of new natural products for which standards are unknown. Selected infrared wavelength detection, available on the proposed instrumentation, will also allow selective monitoring and searching for compounds of desirable classes, such as the phthalides, in plant extracts
