Multistep approach for the structural identification of biotransformation products of iodinated X-ray contrast media by liquid chromatography/hybrid triple quadrupole linear ion trap mass spectrometry and (1)H and (13)C nuclear magnetic resonance.
This study investigated the application of a hybrid triple quadrupole linear ion trap mass spectrometer (Qq-LIT-MS) in combination with NMR to elucidate the chemical structures of 27 biotransformation products (TPs) of the nonionic iodinated X-ray contrast media (ICM), iohexol, iomeprol, and iopamidol, formed in contact with soil. The combination of MS(2) and MS(3) spectra with Qq-LIT-MS was essential to determine the MS fragmentation pathways crucial for structural elucidation. (1)H and (13)C NMR analyses were needed to confirm the chemical structures of TPs proposed by MS fragmentation. Biotransformation occurred exclusively at the side chains of the iodinated X-ray contrast media, while the iodinated benzene ring remained unaltered. Several of the newly identified TPs of the ICM were found in surface water, groundwater, and even drinking water. Concentrations as high as 1450 +/- 110 ng/L (iomeprol TP629) were detected in groundwater that is influenced by wastewater infiltration, and as high as 289 +/- 41 ng/L (iomeprol TP643) in drinking water.
Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, D-56068, Koblenz, Germany.
Jennifer Lynne
JL
Kormos
Manoj
M
Schulz
Manfred
M
Wagner
Thomas A
TA
Ternes
D001711:Biotransformation; D003287:Contrast Media / Q000737:chemistry* / Q000378:metabolism; D007472:Iohexol / Q000737:chemistry* / Q000378:metabolism; D007479:Iopamidol / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
D003287:Contrast Media; D014874:Water Pollutants, Chemical; C057937:iomeprol; D007472:Iohexol; D007479:Iopamidol