MASS-SPECTROMETRIC DETECTION OF CARCINOGEN ADDUCTS

Genotoxic carcinogens interact with nucleic acids and proteins to yield covalently bound products (adducts), the quantitative determination of which has been proposed as a biomonitor of human exposure to carcinogens. Mass spectrometry is playing a leading role both in the structural characterisation and in the quantitative determination of these carcinogen adducts. In particular electrospray ionisation and matrix assisted laser desorption ionisation are being increasingly used in nucleotide and protein adduct detection and in sequencing of carcinogen-modified oligonucleotides and peptides. Quantitative determination of carcinogen-modified nucleic acid bases and protein amino acids is generally carried out by GC/MS or GC/MS/MS, the highest sensitivity being achieved using negative ion chemical ionisation. These techniques are now being applied to samples from humans exposed to carcinogens from environmental, medicinal and occupational sources.