Quantitative determination of DNA adducts using liquid chromatography/electrospray ionization mass spectrometry and liquid chromatography/high-resolution inductively coupled plasma mass spectrometry

✍ Scribed by Siethoff, Christoph; Feldmann, Ingo; Jakubowski, Norbert; Linscheid, Michael

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 147 KB
• Volume: 34
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199904)34:4<421::aid-jms790>3.0.co;2-i

✦ Synopsis

The quantitative determination of nucleotides from DNA modiÐed by styrene oxide is described using a combination of inductively coupled plasma high-resolution mass spectrometry (ICP-HRMS) and electrospray ionization mass spectrometry (ESI-MS), both interfaced to reversed-phase high-performance liquid chromatography (HPLC). LC/ICP-MS (resolution > 1500 to discriminate against 15N16O' and 14N16OH') was employed to determine quantitatively the content of modiÐed nucleotides in standard solutions based on the signal of phosphorus ; phosphoric acid served as an internal standard. By means of the standard addition technique the sensitivity of the LC/ESI-MS approach was subsequently determined. Since a comparison of UV, ICP and ESI-MS data suggested that in ESI-MS the ionization efficiency of the adducts is identical within the error limits, quantitative determination of all adducts is possible. For LC/ESI-MS with single ion monitoring, the detection limit for styrene oxide adducts of nucleotides was determined to be 20 pg absolute or 14 modiÐed in 108 unmodiÐed nucleotides in a 5 lg DNA sample, which comes close to the best methods available for the detection of chemical modiÐcations in DNA