High Performance Analysis of Complex Organic Mixtures

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The primary focus of our research program is to facilitate lab automation and on-site deployment via design of highly automated miniaturized and integrated instrumentation for isolation of organic materials from complex matrices, as well as subsequent separation, identification, and quantification of these species. We are actively pursuing solvent-free, “green” approaches that can integrate both sampling and sample preparation steps and therefore facilitate convenient field deployment and in-vivo determinations. The long-term objective of our efforts is to move analytical chemistry "on-site", where the sample is located, as a means to decrease the cost of analysis, while still delivering rapid and accurate measurement, screening, and monitoring. As part of this ongoing effort, our research team is currently investigating various polymer membrane, sorbent packed needle, and range-sorbent coated support configurations, including fibers, tips, particles, and blades. In the next 5-year research program supported by the Discovery grant, we propose to continue expanding our fundamental understanding of mass transfer in tissue during SPME sampling so as to broaden the scope of its application to more challenging tasks, including protein extraction, metabolomics investigations of live systems. The proposed research will facilitate development of convenient extraction devices, effective methods, and appropriate calibration procedures, resulting in the enablement of highly sensitive detection through application of microextraction principles. The main focus will be development of water and air monitoring methods using on-site instrumentation. Our previous research clearly demonstrated that in-vivo SPME technology, “chemical biopsy”, can effectively isolate metabolite composition, including unstable compounds, from various investigated systems, a feat which facilitates correct characterization of living systems. SPME also provides complementary in-vivo information to microdialysis, as it provides better coverage of lipophilic compounds. Considering the above, we have been expanding our research in the area of in-vivo lipidomics, given that many lipids are good disease biomarkers. While most sample preparation devices are typically coupled to chromatography, we have recently considered direct coupling of devices to mass spectrometry and/or ion mobility spectrometry, taking advantage of the separation power of these devices. To facilitate this line of research, we have been developing a new approach to ion mobility via focusing of ions in the separation channel. This unique approach not only results in higher sensitivity due to focusing, but also facilitates enhancement in selectivity, as it enables effective exploration of cluster formation by addition of appropriate compounds (“modifiers”) to the drift gas. System based on such principle will be designed to be portable and compact enough so as to even allow for their placement onto a cellphone device