- Micro-chemical analysis
- Liquid chromatography, capillary
electrophoresis and electrochromatography - New chromatographic packing materials
- New approaches for drug analysis in cells
- B. S., University of Puerto Rico at Cayey (1981)
- Ph.D., UMASS-Lowell (1991)
- Postdoctoral Research Associate, Stanford University (06/1991-06/1993)
- NSF Minority Research Initiation Award (1994)
- The Whitaker Foundation Fellow (1994-1997)
- NSF Award for Special Creativity (1999-2001)
- The Americas Editor for The Analyst (01/2001-06/2007)
- The 2003 Faculty of the Year Award, Compact for Faculty Diversity and AGEP
- The Optimista Award - 2005 Hispanic Scholarship Fund Alumni Hall of Fame inductee
Research interests include: micro/nano-chemical analysis, capillary electrophoresis and electrochromatography, liquid chromatography, chromatographic stationary phases/materials, bioanalytical chemistry, drug analysis in biological fluids
Ongoing efforts in our laboratory focus on column technology for liquid chromatography since it is within the column that the chromatographic processes take place -- the column is the “heart” of the separation system. New silica based organic-inorganic hybrid composites as well as metal oxides from the group IV of the periodic table are synthesized and studied as chromatographic support materials. We investigate the physicochemical characteristics of these materials and how such characteristics influence chemical separations. A fundamental understanding of chromatographic materials is critical to assess the intermolecular interactions governing the separation process, leading to the tailoring of phases with desired chromatographic properties. Our materials are synthesized in different formats suitable for HPLC, such as particulates, thin films, and monolithic structures. For example, we have synthesized organo-silica nanoparticles to explore the limits of particle size and their potential use in capillary electrochromatography and capillary HPLC. The use of small particle sizes has led to research in the area of ultrahigh pressure liquid chromatography (pressures as high as 50,000 psi). In addition to particulates, monoliths of hafnia, zirconia, and silica hybrids are under investigation, as well as the solution chemistry that leads to such structures.
Another area of study is the implementation of fast separation methodology with applicability to proteomics and high throughput analysis. We also use various separation technologies (e.g., LC/MS) to analyze samples of biological origin (e.g., saliva, transdermally collected samples, and tear fluid), exploring the potential of such fluids as a mean to sample chemical species suitable for clinical analysis/diagnosis. Our efforts on developing new methodology to analyze entities of biochemical interest (proteins, DNA, drugs, metal ion complexes, etc.) have impacts in many areas (e.g., environmental, biomedical, pharmaceutical, etc.). One particular area of interest is the development of new approaches to analyze antiviral drugs in single cells.
Selected Recent Publications