Erbacher C, Flothkötter N, Macke M, Quarles CD, Sperling M, Müller J, Karst U. A fast and automated separation and quantification method for bromine speciation analyzing bromide and 5-bromo-2'-deoxyuridine in enzymatically digested DNA samples via ion chromatography-inductively coupled plasma-mass spectrometry.
J Chromatogr A 2021;
1652:462370. [PMID:
34246961 DOI:
10.1016/j.chroma.2021.462370]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 11/24/2022]
Abstract
A fast and automated separation and quantification method for bromide and the artificial nucleoside 5-bromo-2'-deoxyuridine (5-BrdU) via hyphenation of ion exchange chromatography (IC) and inductively coupled plasma-mass spectrometry (ICP-MS) is presented. The analysis of these two species is relevant to monitor the transfer of electrons along metal-mediated DNA base pairs. Charge transfer in DNA is of high interest for the implementation in nanotechnological applications like molecular wires. 5-BrdU as part of the DNA sequence releases bromide upon one electron reduction after efficient electron transfer along the DNA. The concentrations of 5-BrdU and bromide in enzymatically digested DNA samples can therefore be used as a marker for the efficiency of electron transfer along the DNA helix. A large number of samples was analyzed using an automated IC system. This platform enables time-efficient external calibration by inline dilution of a stock solution. Due to the fast separation of the two bromine species in less than 90 s, the developed method is suitable for screening applications with a multitude of samples. Despite the isobaric interferences and a low degree of ionization for bromine detection via ICP-MS the method has a limit of detection (LOD) of 30 ng/L which is approximately an order of magnitude lower than a comparable method using reversed phase high performance liquid chromatography (RP-HPLC) and ICP-MS.
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