A gas chromatography/electron capture/negative chemical ionization high-resolution mass spectrometry method for analysis of endogenous and exogenous N7-(2-hydroxyethyl)guanine in rodents and its potential for human biological monitoring
- PMID: 10458706
- DOI: 10.1021/tx990059n
A gas chromatography/electron capture/negative chemical ionization high-resolution mass spectrometry method for analysis of endogenous and exogenous N7-(2-hydroxyethyl)guanine in rodents and its potential for human biological monitoring
Abstract
A gas chromatography/electron capture/negative chemical ionization high-resolution mass spectrometry (GC/EC/NCI-HRMS) method was developed for quantitating N7-(2-hydroxyethyl)guanine (N7-HEG) with excellent sensitivity and specificity. [4,5,6,8-(13)C(4)]-N7-HEG was synthesized, characterized, and quantitated using HPLC/electrospray ionization mass spectrometry (HPLC/ESI-MS) so it could serve as an internal standard. After being converted to its corresponding xanthine and derivatized with pentafluorobenzyl (PFB) bromide twice, the PFB derivative of N7-HEG was characterized using GC/EC/NCI-HRMS carried out at full scan mode. The most abundant fragment was at m/z 555, with a molecular formula of C(21)H(9)N(4)O(3)F(10), resulting from the loss of one PFB group. By monitoring m/z 555.0515 (analyte) and m/z 559.0649 (internal standard), this assay demonstrated a linear relationship over a range of 1 fmol to 1 pmol of N7-HEG versus 20 fmol of [(13)C(4)]-N7-HEG on column. The limit of detection (LOD) for the complete assay was 600 amol (S/N = 5) injected on column. The variation of this assay was within 15% from 1 to 20 fmol of N7-HEG versus 2 fmol of [(13)C(4)]-N7-HEG with four replications for each calibration standard. Two hundred to three hundred micrograms of spleen DNA of control rats and mice and 100 microg of spleen DNA of rats and mice exposed to 3000 ppm ethylene for 6 h/day for 5 days were analyzed using GC/EC/NCI-HRMS. The amounts of N7-HEG varied from 0.2 to 0.3 pmol/micromol of guanine in tissues of control rats. Ethylene-exposed animals had 5-15-fold higher N7-HEG levels than controls. This assay was able to quantitate N7-HEG in 25-30 microg of DNA from human lymphocytes with excellent specificity. This was due in part to human tissues having 10-15-fold higher amounts of endogenous N7-HEG than rodents. These results show that this GC/EC/NCI-HRMS method is highly sensitive and specific and can be used in biological monitoring and molecular dosimetry and molecular epidemiology studies.
Similar articles
-
Measurement of N7-(2'-hydroxyethyl)guanine in human DNA by gas chromatography electron capture mass spectrometry.Chem Res Toxicol. 2005 Jan;18(1):70-5. doi: 10.1021/tx049854d. Chem Res Toxicol. 2005. PMID: 15651851
-
Quantitative detection of N(7)-(2-hydroxyethyl)guanine adducts in DNA using high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.J Mass Spectrom. 2001 Mar;36(3):336-43. doi: 10.1002/jms.132. J Mass Spectrom. 2001. PMID: 11312526
-
Application of gas chromatography/electron capture negative chemical ionization high-resolution mass spectrometry for analysis of DNA and protein adducts.Chem Res Toxicol. 1998 May;11(5):520-6. doi: 10.1021/tx9702042. Chem Res Toxicol. 1998. PMID: 9585483
-
The application of mass spectrometry in molecular dosimetry: ethylene oxide as an example.Mass Spectrom Rev. 2011 Sep-Oct;30(5):733-56. doi: 10.1002/mas.20299. Epub 2011 Feb 16. Mass Spectrom Rev. 2011. PMID: 21328599 Review.
-
Macromolecular adducts of ethylene oxide: a literature review and a time-course study on the formation of 7-(2-hydroxyethyl)guanine following exposures of rats by inhalation.Mutat Res. 1990 Nov-Dec;233(1-2):151-64. doi: 10.1016/0027-5107(90)90159-2. Mutat Res. 1990. PMID: 2233797 Review.
Cited by
-
Mode of action-based risk assessment of genotoxic carcinogens.Arch Toxicol. 2020 Jun;94(6):1787-1877. doi: 10.1007/s00204-020-02733-2. Epub 2020 Jun 15. Arch Toxicol. 2020. PMID: 32542409 Free PMC article. Review.
-
Understanding the importance of low-molecular weight (ethylene oxide- and propylene oxide-induced) DNA adducts and mutations in risk assessment: Insights from 15 years of research and collaborative discussions.Environ Mol Mutagen. 2019 Mar;60(2):100-121. doi: 10.1002/em.22248. Epub 2018 Dec 10. Environ Mol Mutagen. 2019. PMID: 30536466 Free PMC article. Review.
-
Ethylene oxide in blood of ethylene-exposed B6C3F1 mice, Fischer 344 rats, and humans.Toxicol Sci. 2013 Dec;136(2):344-58. doi: 10.1093/toxsci/kft218. Epub 2013 Sep 25. Toxicol Sci. 2013. PMID: 24068676 Free PMC article.
-
The formation and biological significance of N7-guanine adducts.Mutat Res. 2009 Aug;678(2):76-94. doi: 10.1016/j.mrgentox.2009.05.006. Epub 2009 May 22. Mutat Res. 2009. PMID: 19465146 Free PMC article. Review.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Miscellaneous