Feb 17, 2016 – NMR Topical Group Meeting

Abstract

Dissolved organic matter (DOM) plays important ecological and environmental roles in natural waters; these include acting as a short-term sink of atmospheric CO₂, a bacterial food source, and as a reactant and absorbent of man-made pollutants. The relative importance of DOM’s various roles in an aquatic system depend mainly on its chemical composition. Unfortunately little is known about its chemical composition or even the manner in which it forms due mainly to its complex chemical nature.

Applying two dimensional correlation spectroscopy to ¹³C-NMR and FTIR spectra of the high molecular-weight dissolved organic matter (HMW-DOM) isolated along an Elizabeth River/Chesapeake Bay salinity transect shows that HMW-DOM consists of three major components that have different biogeochemical reactivities. Coupling these results with proton nuclear magnetic resonance (¹H-NMR) by 2D- correlation analysis give us more insightful characterization of the chemical nature of each of these three major components and reveals that each of these components contains mixtures of compounds that share similar major functional groups but have significant differences in other minor functional groups.

Employing 2D correlation to Fourier transform ion cyclotron resonance (FT-ICR) mass spectra allows us to more closely examine changes that occur in the DOM at the molecular level and understand how these thousands of individual compounds are correlated with each other and how they respond to different external perturbations. The power of this technique is its ability to be used on either the presence/absence of the individual peaks or on their normalized magnitudes. The presence or absence of the peaks are utilized to identify the reactivity and correlation between peaks that plot in different regions of the van Krevelen diagram, whereas the normalized magnitudes are used to correlate the changes among individual peaks. One of the promising advantages of 2D correlation of FTICR-MS data is the ability to associate the variations of the individual peaks with the changes in the functional groups that are measured by other spectroscopic techniques. This approach takes us one step further, from identifying molecular formulas to proposing chemical structures.

Times

6:00 pm   Dinner
7:00 pm  Seminar

Venue

Rutgers University, Busch Campus,
CABM, Room 010 (Center for Advanced Biotechnology and Medicine)
679 Hoes Lane West, Piscataway NJ 08854

Dinner Cost:

Dinner cost: $15 employed / $5 students, postdoc, retired, unemployed — payable at the door
No charge for seminar only.

Directions to Rutgers University, Busch Campus

Questions: frank.rinaldi@bms.com or Anuji.Abraham@bms.com

Register:

Please register online here or via e-mail to frank.rinaldi@bms.com