CAPILLARY ELECTROCHROMATOGRAPHY AND CAPILLARY ELECTROCHROMATOGRAPHY MASS-SPECTROMETRY FOR THE ANALYSIS OF DNA ADDUCT MIXTURES

Capillary electrochromatography (CEC) is an emerging technique that ca n be applied to the separation of neutral compound mixtures and provid es a versatile alternative to micellar electrokinetic chromatography. In this paper, CEC is applied to the separation of polycyclic aromatic hydrocarbons (PAHs) and in vitro reaction products of PAH deoxynucleo side adducts. Some unique features related to CEC, such as convenience of stopping the flow, nanoliter now rate, and low sample consumption, are discussed. On-column focusing in CEC can be conducted by introduc ing the analytes in a solution of lower solvent strength followed by e lution with a stronger mobile phase, in a manner analogous to that use d in normal HPLC (e.g., a 10-fold preconcentration factor can be readi ly achieved). Coupling of CEC to mass spectrometry for the detection o f a relatively dilute DNA adduct mixture solution (10(-6) M) using the on-column focusing method is also presented.