Superfund Research Program

Chemistry and Analytical Core

Project Leader: Avram Gold
Co-Investigator: Wanda M. Bodnar
Grant Number: P42ES005948
Funding Period: 1995-2018

Project-Specific Links

Final Progress Reports

Year:   2017  2005 

A high-throughput liquid chromatography-mass spectrometry (LC-MS) instrument is being purchased with funding from the North Carolina Biotechnology Center, and is in the process of being set up. Funding was also obtained from the NIH NCRR Shared Instrument Grant program to purchase a high-performance, high-sensitivity LC-MS system. Addition of one more LC-MS/MS system will significantly enhance the capability of the Mass Spectrometry center to offer analytical services, and alleviate the pressure on use noted in the previous year’s progress report. The Chemistry facility continues to provide MS and NMR spectroscopic identification to Project 1, and standards for cysteine adducts to Projects 3 and 8. In addition, the Core has been tasked with providing QA analytical support to Project 6.

In support of Project 1, preparation of modified aldehyde-reactive probes, initiated in prior years, has produced two of the target compounds. In search of routes to direct synthesis of potential products of further oxidation of oxidized DNA bases, 2-electron oxidation of guanine with 1.1 molar excess dimethyldioxirane gives racemic 4-carboxamido-4-formamido-2-iminohydantoin as the sole product. The structure was established by mass spectrometry and multidimensional and multinuclear NMR studies, and supported by oxidation of the isotopomers [4-¹³C] and [7-¹⁵N]guanine, which yield [4-¹³C]iminohydantoin and [7-¹⁵N]iminohydantoin respectively. The distribution of ¹³C and ¹⁵N labels in the isotopomeric products supports initial oxidation of C4-C5 bond of guanine followed by a 1,2 acyl migration of guanine C6. This iminohydantoin represents a novel, stable primary DNA lesion.

In support of Project 4, universally ¹³C-labeled pyrene was prepared, purified and characterized, and supplied to serve as a substrate to probe a bioreactor for the presence of bacteria capable of degrading pyrene. The ability of the core to synthesize uniformly ¹³C-labeled PAHs has enabled this project with the unique capability to use an emerging cultivation-independent method to identify PAH-degrading bacteria in complex systems.

In support of Project 6, LC techniques are being evaluated to provide QA analysis of surfactants in solutions generated by the brine barrier remediation technology in the Dover field study.

In support of Project 8, S-(phenyl)-, S-(1-naphthyl)- and S-(2-naphthyl)-cysteine continue to be provided to support preparation of immunoaffinity columns for purification of antibodies and as standards for development of ELISAs for detection of protein adducts of aromatic compounds as measures of dermal exposure to aromatic solvents. Preliminary experiments are being conducted to evaluate the metabolism of naphthalene by skin preparations.