Electron–capture mass spectrometry: recent advances

Liquid chromatography-electrospray ionization-mass spectrometry: the future of DNA adduct detection

“…However GC-MS has been more extensively used for the determination of protein adducts, which act as surrogate markers of exposure to carcinogens (42,73,74). Numerous DNA adducts have been studied using gas chromatographyelectron capture negative chemical ionization mass spectrometry (GC-EC-NCI-MS) and comprehensive reviews on electron capture MS have been published by Giese (2000) as well as Leis et al (2004) (75,76). DNA base adducts which have been studied using this technique include malondialdehyde-guanine, N-7 (2-hydroxyethyl)guanine (N-7(2-OHEt)G), N 2 ,N-3 ethenoguanine, N-1,N 2 ethenoguanine and N-1, N 6 ethenoadenine (77-80).…”

Electron capture atmospheric pressure photoionization mass spectrometry: analysis of fullerenes, perfluorinated compounds, and pentafluorobenzyl derivatives

“…some fullerenes and perfluorinated compounds. The unusually high yield of ionization products led us to propose an EC ionization mechanism, which has previously been extremely successful in trace level analysis, most familiarly in the forms of EC-NICI 53 and EC-APCI. 54 An EC ionization mechanism for negative-ion APPI has been further proven by the fact that pentafluorobenzyl (PFB)-derivatized phenols readily underwent dissociative EC reaction, a signature process of EC-NICI 55 and EC-APCI, 56 and generated exclusively negative phenolate ions.…”

Analysis of 7‐methylguanine using isotope dilution and gas chromatography/electron‐capture negative chemical ionization mass spectrometry

“…[18][19][20][21] These biomarkers, when quantitatively analyzed, could provide an objective measure for determining the effectiveness of interventions to lower exposure and risk. 22 Analysis of the chemically specific biomarker 7-MG in blood or urine of humans could serve as a valuable biomarker for cancer patients treated with dacarbazine as a risk-associated indicator of secondary cancers.…”

“…Derivatization of alkylated DNA adducts with electrophores such as PFBBr, and analysis of the derivatives using electron-capture mass spectrometry (EC-MS), has been proved to be highly sensitive and specific. 16,21 The sensitivity of this method was attributed to the fact that the PFB derivatives are strong electrophores and are able to capture thermal or near-thermal electrons to form dominant anion products with approximately 100% efficiency. 18,20 Results from the present study are consistent with the observation that analysis of PFB-derivatized 7-MG using EC-MS operated under SIM mode is extremely sensitive, and has a detection limit in the 20 amol range at signal-to-noise (S/N) ratio !10; however, the limit of quantitation was estimated to be in the 100 amol range in tissue samples (data not shown) at S/N ratio greater than 10.…”