|About Us - Senior Scientist Biographies and Publications|
Provides leadership to the Laboratory. Develops chromatographic profiling methods for phenolic compounds in plant materials. Develops spectral fingerprinting and chromatographic profiling methods for characterization of food materials. Applies pattern recognition methods to identification of cultivar, growing site, growing and processing conditions, and chemical variance.
Develops methods for separation and identification of vitamin D, lipids and lipid-related molecules using high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS). Expertise in atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry for triacylglycerol, sphingolipid and vitamin D analysis. Developed 'dual parallel mass spectrometry' methods in which both APCI-MS and ESI-MS data are acquired simultaneously, in parallel. The current focus is on Vitamin D analysis of foods to provide updated data for the National Nutrient Database.
Performs analytical method development using mass spectrometry, HPLC, and GC. Current focuses are 1. Determination and quantitation of water-soluble vitamins using isotope dilution LC/MS, 2. Determination and quantitation of phytonutrients in food supplements using LC/MS and/or LC/MS/MS.
Designs and develops analytical procedures for analysis of bioactive nutrients in fruits, vegetables, grains and other foods. Four focus areas of the current research are: 1. To evaluate the impact of sample preparation and extraction procedures on assays of bioactive compounds, 2. Chemical investigation of foods for isolation, characterization and analysis of bioactive components, 3. Separation and quantification of phenolic compounds in common foods by different spectroscopic and chromatographic procedures to generate data for the National Nutrient Databank, and 4. Development of rapid high-throughput pattern recognition procedures for screening a variety of foods.
Develops high-precision analytical methodologies based on isotope dilution mass spectrometry for the determination of food components, such as selenomethionine and water soluble vitamins. Develops new methodologies for the HPLC determination of water-soluble vitamins and the GC/PFPD determination of selenium species in foods. Works with the National Institute of Standards and Technology, AOAC International and other organizations to facilitate the availability and use of food-related standard materials.