Identification of potentially mutagenic contaminants in the aquatic environment by liquid chromatographic—thermospray mass spectrometric characterization of in vitro DNA adducts

• Published in: Journal of Chromatography A 1994-10, Vol.684 (1), p.113-119
• Main Authors: Kuehl, Douglas W., Serrano, Jose, Naumann, Sandra
• Format: Article
• Language: English
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(94)89137-0

Liquid chromatographic—thermospray mass spectrometric (LC—TSP-MS) characterization of chemical adducts of DNA formed during in vitro reactions is proposed as an analytical technique to detect and identify those contaminants in aqueous environmental samples which have the propensity to be genotoxic, i.e. to covalently bond to DNA. The approach for direct-acting chemicals includes the in vitro incubation of DNA with contaminated aqueous samples at 37°C, pH 7.0 for 0.5 to 6 h, followed by enzymatic hydrolysis of the DNA to deoxynucleosides and LC—TSP-MS analysis of the resultant solution. A series of allylic reagents was used as model reactive electrophiles in synthetic aqueous samples to demonstrate that adduct formation was linear with both contaminant concentration and electrophilic reactivity potential. The characterizations can also estimate the proportion of bonding to different sites on a base, for instance, the ratio of O 6 - to 7-alkylguanine (oxygen vs. nitrogen bonding) products, which is an important parameter in assessing the genotoxicology of chemicals.