Comparison between capillary and nano liquid chromatography-electrospray mass spectrometry for the analysis of minor DNA-melphalan adducts.
Nano liquid chromatography (nanoLC) coupled to electrospray mass spectrometry (ES-MS) was evaluated for the analysis of DNA adducts in melphalan-treated Jurkat cells. The detection limit of the nanoLC-ES-MS-MS system was assessed using a dAMP-melphalan adduct. Compared to capillary liquid chromatography (capLC) ES-MS the absolute detection limit could be improved by a factor 10, leading to the detection of 395 fg dAMP-melphalan adduct under single-ion monitoring conditions at a S/N of 14. Minor adducts such as cross-linked adducts could be detected in in vitro solutions of 2'-deoxynucleotides (dNMP) treated with melphalan using column-switching nanoLC-ES-MS. These adducts were not found using capLC-ES-MS. More detailed structural information of the alkylation sites was obtained by examining the nanoLC-ES-MS-MS data. Jurkat cells were treated with melphalan, the modified DNA was isolated and enzymatically hydrolyzed. Several modified dinucleotides were identified, the most abundant adducts were pdG(Mel(Cl))pdC (m/z=453, t(r)=17.0 min) and pdG(Mel(OH)) pdC ring opened (m/z=453, t(r)=39.5 min).
Hoes
I
I
Department of Chemistry, University of Antwerp, Belgium.
Van Dongen
W
W
Lemière
F
F
Esmans
E L
EL
Van Bockstaele
D
D
Berneman
Z N
ZN
D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D004247:DNA / Q000737:chemistry; D018736:DNA Adducts / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D019169:Jurkat Cells; D008558:Melphalan / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D018736:DNA Adducts; D004247:DNA; D008558:Melphalan