Sample stacking is used to improve the detection limits of capillary zone electrophoresis coupled to continuous flow fast atom bombardment mass spectrometry for the analysis of DNA adducts. It was found that, with stacking, the concentration detection limit of deoxynucleotide adducts could be improved by as much as 3 orders of magnitude, thereby bringing it into the 10(-8) M range. In addition, the mass spectrometric mass detection limits of a model acetylaminofluorene deoxyguanosine 5'-monophosphate adduct were found to be in the low picomole range for full scanning and the low femtomole range for multiple reaction monitoring of a selected fragmentation. The techniques have been applied to the analysis of adducts formed in the in vitro reaction of N-acetoxy-N-acetyl-2-aminofluorene with DNA.

Capillary liquid chromatography-continuous-flow fast atom bombardment mass spectrometry is applied to the detection of deoxynucleoside adducts of N-acetoxy-N-acetyl-2-aminofluorene. In such a configuration, normal scan and tandem mass spectrometric techniques are shown to provide useful structural information for an N-acetyl-N-(deoxyguanosin-8-yl)-2-aminofluorene adduct standard for low- nanogram (low-picomole) amounts sampled. In addition, multiple reaction monitoring gives limits of detection below 25 pg (50 fmol) for this adduct, suggesting the potential for routine screening of intact deoxynucleoside adducts formed below the 1:10(6) level from as little as 1 mg of DNA. When applied to the analysis of the products of an in vitro reaction of calf thymus DNA with N-acetoxy-N-acetyl-2-aminofluorene, these techniques are readily able to detect and supply structural data for the N2 and C8 deoxyguanosine adducts formed.

The extent and distribution of N‐glycosylation and the nature of most of the disulfide bond linkages were determined for bovine lactoperoxidase through proteolytic and glycolytic digestions combined with matrix‐assisted laser desorption/ionization mass spectrometric analysis. In addition, 98% of the primary sequence of the protein was confirmed. All five of the asparagines present in sequons were found to be glycosylated, predominantly by high mannose and complex structures. Six disulfide bonds were assigned, including Cys 32–Cys 45, Cys 146–Cys 156, Cys 150–Cys 174, Cys 254–Cys 265, Cys 473–Cys 530 and Cys 571–Cys 596. Copyright © 2000 John Wiley & Sons, Ltd.

Capillary zone electrophoresis coupled to continuous flow-fast atom bombardment mass spectrometry is shown to have utility for the detection and characterization of adducts formed by the covalent attachment of four polyaromatic hydrocarbon (PAH) and amino-PAH compounds to deoxyguanosine. Normal scanning provided structural information for a 1.3 ng injection of a model adduct, while 1.3 ng of each of a mixture of adducts was sufficient to determine their molecular weights by monitoring the constant neutral loss of deoxyribose. Exploitation of this loss in the multiple reaction monitoring mode resulted in the detection of low picogram amounts of target adducts in mixtures.

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