Du Laing, Gijs

Folens, Karel

Vanhaecke, Frank

English

Ghent University Academic Bibliography

TEMP042QUANTITATIVE DETERMINATION OF GADOLINIUM BASEDMAGNETIC RESONANCE IMAGING CONTRAST AGENTS IN URINEAND HOSPITAL WASTEWATER BY HPLC-ICP-QMSKarel Folens (2), Frank Vanhaecke (1), Gijs Du Laing (2)1) Department of Analytical Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S12, 9000 Gent, Belgium.2) Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, CoupureLinks 653, 9000 Gent, Belgium.BackgroundRare earth elements (REE) are a class of 17 elements consisting of the lanthanide elements with atomic number56 (La) till 71 (Lu) and yttrium and scandium. They generally have similar chemical and physical properties,hindering a complete element purification. [1] To some exceptions, most REE have a III+ oxidation state and 6to 8 coordination number, so does also gadolinium (Gd). [2] The ion with electron configuration 64Gd3+ : [54Xe]4f7 is known paramagnetic, having the highest spin magnetic momentum S of +7/2. Besides other applicationssuch as in permanent magnets, glass additives and as shield in neutron radiography, it is therefore used in themedical field as a chemical contrast agent for magnetic resonance imaging (MRI) scan. The cation is chelated byorganic linkers of diethylene triamine pentaacetic acid (DTPA), diethylene triamine pentaacetic acidbismethylaminde (DTPA-BMA) or tetraazacyclododecane (DOTA). [3] Occurrence of free Gd3+ is highly toxicto humans as it interchanges with Ca2+ and Zn2+ in biomolecules [4] and accumulates in the liver, bones, lymphnodes and skin up to 4.6 mg kg-1. [5]Chromatographic speciation methodThe chromatographic method [3] was adjusted for separation of three most currently applied MRI contrast agentsto the optimal conditions. A Perkin Elmer 200 Series HPLC system was coupled through a six way switchingvalve to a Perkin Elmer Elan DRCe Inductively Coupled Plasma Quadrupole Mass Spectrometer for detection ofGd. Limits of detection were calculated by formula with Sbl the blanc surface area and a the sensitivity obtainedfrom calibration of 0 till 250 µg L-1 Gd standards in Milli-Q water and criteria of R2 > 0.995. The resultingvalues for Gd-DTPA, Gd-DOTA and Gd-DTPA-BMA amount 44, 61 and 83 ng L-1.Degradation behavior of Gd based contrast agents and presence in hospital wastewaterThe described method was used to analyze the wastewater of a medium sized hospital in Ghent, Belgium, wherepatients were treated with contrast agents for MRI. Gd was found in a total concentration of 18.4 µg L-1 at the pHof 7.7 and 660 mg L-1 of chloride, 102 mg L-1 of sulphate and 28 mg L-1 of nitrate ions present. From theobtained chromatogram (Fig 1), two peaks of Gd-DTPA and Gd-DOTA can be distinguished. The occurrence ofnative species in the effluent corresponds well to degradation studies in water that revealed 95%, 83% and 100%of Gd-DTPA, Gd-DOTA and Gd-DTPA-BMA respectively were unaffected after 14 days of incubation at 37 °C.Degradation was expressed to a much further extend when performed in urine matrix, indicating the significantrole of other ions or biomolecules.Conclusions and perspectivesQuantification of Gd-DTPA, Gd-DOTA and Gd-DTPA-BMA contrast agents was successfully established byHPLC coupled to ICP-QMS. Ions and biomolecules present in the urine matrix showed a large influence on thedegradation of Gd, but the impact of individual compounds requires further examination. In the specific hospitalwastewater, mostly parent Gd-DTPA and Gd-DOTA was observed. A selective recovery strategy shouldtherefore definitely take into account the organic nature of Gd based contrast agents. On this basis, the behaviorof Gd in the environment and removal of single contrast agents is yet subject of study.References1) I. McGill (2012) Rare Earth Elements, 31, Ullmann’s Encyclopedia of Industrial Chemistry, 183-228.2) S. Cotton (2006) Lanthanide and Actinide Chemistry, John Wiley & Sons.3) M. Birka, C. Wehe, L. Telgmann, M. Sperling, U. Karst (2013) Sensitive quantification of gadolinium-based magneticresonance imaging contrast agents in surface waters using hydrophilic interaction liquid chromatography and inductivelycoupled plasma sector field mass spectrometry. Journal of Chromatography A, 1308, 125-131.4) C. Raju, D. Lück, H. Scharf, N. Jakubowski, U. Panne (2010) A novel solid phase extraction method for pre-concentrationof gadolinium and gadolinium based MRI contrast agents from the environment, Journal of Analytical Atomic Spectrometry,25, 1573-1580.5) A. Steuerwald, P. Parsons, J. Arnason, Z. Chen, C. Peterson, G. Louis (2013) Trace element analysis of human urinecollected after administration of Gd-based MRI contrast agents: characterizing spectral interferences using inorganic massspectrometry, Journal of Analytical Atomic Spectrometry, 28, 821-830.

Quantitative determination of gadolinium based magnetic resonance imaging contrast agents in urine and hospital wastewater by HPLC-ICP-QMS

https://biblio.ugent.be/publication/7100944/file/7101068

Quantitative determination of gadolinium based magnetic resonance imaging contrast agents in urine and hospital wastewater by HPLC-ICP-QMS

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