Abstract 4661: Analysis of DNA adducts: Development of a high-performance analytical platform to meet challenges in human health

Abstract

The outstanding selectivity and sensitivity of the atmospheric pressure laser ionization (APLI), which is a two-photon ionization process, in combination with a mass spectrometric detection, is demonstrated for the analysis of DNA adducts. Preparative HPLC with a HILIC-phase and a fraction sampler was used to separate the polar 4-hydroxy-1-(3-pyridyl)-butanone (HPB) and 4-hydroxy-1-(3-pyridyl)-butanol (Diol), which will be formed after acid hydrolysis of the POB- and PHB-DNA adducts. The adducts eluted in the fractions to be analyzed were collected, concentrated to dryness and dissolved in dichloromethane. Then 4-(dimethylamino)pyridine as a base, N,N′-dicyclohexylcarbodiimide as an activator and anthracene-9-yl-methoxyacetic acid as an ionization marker, in analogy to a fluorescence marker, were added, and after several hours at 35 °C the sample was injected into an HPLC-APLI-TOF(MS). With this novel method, only aromatic compounds are ionizable; because the ionization marker of the DNA adducts carries an aromatic group, this allows ionization by the two-photon process. For the first time we have used a new strategy to analyse DNA adducts by HPLC-APLI-TOF(MS) after derivatization with an ionization marker. To demonstrate the utilizability of this method, we analyzed POB and PHB adducts, which are formed by metabolic activation pathways from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N′-nitrosonornicotine (NNN). In summary, we have demonstrated that the derivatization strategy significantly increases the analytical applicability of APLI-MS and shows new methods for the important DNA adduct analysis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4661. doi:10.1158/1538-7445.AM2011-4661