Unit:
Κατεύθυνση Χημική Ανάλυση-Έλεγχος ΠοιότηταςLibrary of the School of Science
Author:
Petropoulou Georgia
Supervisors info:
Μπακέας Ευάγγελος, Αναπληρωτής Καθηγητής, Tμήμα Χημείας, ΕΚΠΑ
Original Title:
Ανάπτυξη μεθόδου για τη ανίχνευση αναβολικών ανδρογόνων στεροειδών με υγροχρωματογραφία - φασματομετρία μαζών μετά από παραγωγοποίηση
Translated title:
Development of a screening method for the detection of anabolic androgenic steroids by liquid chromatography - mass spectrometry after derivatization
Summary:
Anabolic androgenic steroids (AAS) present limitations regarding their detection using liquid chromatography coupled to mass spectrometry via soft ionization of atmospheric pressure interfaces (e.g. ESI, APCI). Difficulties in the ionization of AAS are resulted from the absence of acidic or basic groups and the low proton affinity of carbonyl and hydroxyl groups.
In the present thesis the aim was the development of an AAS detection method with LC-QTOF instrumentation for doping control, after derivatization with 1,1'-carbonyldiimidazole (CDI) that introduces the imidazole group in the steroids molecule thus enhancing their ionization capability. The derivatization reaction conditions (solvent, derivatization reagent concentration, presence of catalyst, incubation time and temperature) were optimized. Moreover, various parameters of the chromatographic analysis were examined in order to improve the sensitive detection of analytes in spiked urine samples.
The developed method can be used for screening for AAS. Several quality parameters of the method (limit of detection, matrix interferences and chromatographic characteristics) were evaluated according to the International Standard for Laboratories by WADA. The developed method reliably detects 26 out of 34 examined analytes with limits of detection ranging from 2 ng/mL to 10 ng/mL.
MS-MS fragmentation of the derivatives was also investigated and the obtained results demonstrated that the fragmentation of steroid imidazole carbamates is characterized by abundant ions due to the neutral loss of carbon dioxide and imidazole-1-carboxylic acid from the protonated molecular ion.
Main subject category:
Science
Keywords:
anabolic androgenic steroids, derivatization, liquid chromatography, mass spectrometry, doping
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ΠΕΤΡΟΠΟΥΛΟΥ ΓΕΩΡΓΙΑ.pdf
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