"Metabolomics and Natural Product Analysis using High Resolution Mass Spectrometry"
presented by Dr. Sunia Trauger from Harvard FAS Center for Systems Biology
Abstract: The use of high resolution mass spectrometry presents unique challenges in metabolomics. Unlike other omics techniques, structural identification can become a bottleneck in the process. At Harvard, our lab is involved in multiple collaborations where the sample composition can vary greatly and samples originate from diverse origins. This makes it necessary to have multiple methods at our disposal which are capable of characterizing different classes of molecules with differing physical properties. The extraction and chromatography method applied is often adapted according to the molecules of interest. Our workflow either involves looking for ions of interest, using high mass precision of the Bruker Impact or an untargeted approach where two or more sets of samples are profiled using LC-MS to distinguish their differences the molecular level. Thousands of ions are detected in each LC-MS analysis. Comparison of these “features” that represent distinct metabolites is performed using bioinformatics tools like XCMS and Profile Analysis. Putative identifications are verified with MS/MS and retention time confirmation. An on-going collaborative study with poison dart frogs will be presented where alkaloid profiles that distinguish geographically isolated populations are characterized with LC-MS and GC-MS.
"Determination of Illegal Drug Residues on Paper Currency of Macao"
Student Speaker: Lockie Ieong from University of New Haven
Abstract: Currency testing as a means for monitoring drug circulation in the environment can provide objective and timely epidemiological information about types of illegal drugs abused and trafficked. Macao, which is recognized the largest gaming city in the world and one of international travel cities in East Asia, was selected for the study. The recent expansion of tourism and gambling industry in Macao has brought economic prosperity; however, the number of drug offenses (social cost) has also increased. A study was performed to determine types of Illegal drug residues on Macao paper currency and to understand potential implication of drug contamination on surfaces. The analysis method consisted of solvent extraction, solid-phase concentration, and LC-MS detection. Results showed significant amounts of drug residues on currency, with a drug profile that was geographically specific for Macao and its neighboring regions. The results also demonstrated that surface contamination with illegal drugs of surfaces should be taken into account when drug analysis is used in criminal convictions, and underscores the importance of environmental factors when interpreting positive drug test results.