title: Mass spectrometric identification of degradation products of insulin and its long-acting analogues in human urine for doping control purposes.
abstract: The search for target analytes to uncover the misuse of long acting insulin analogues (Lantus, Insulin Glargine; Levemir, Insulin Detemir) in doping control samples led to the identification of several degradation products of insulin or its synthetic analogues. Specimens obtained from healthy volunteers or patients and athletes suffering from diabetes mellitus contained DesB30, DesB24-30, and DesB25-30 human insulin or DesB30-32, DesB31-32, and DesB24-32 Lantus, respectively. Analytes were purified from urine by immunoaffinity chromatography (IAC) with subsequent liquid chromatography-tandem mass spectrometry analysis. The employed analytical procedure was validated for qualitative determination considering the main metabolic products DesB30 human insulin and DesB30-32 Lantus. The occurrence of the identified Lantus degradation products in urine provided the direct and unambiguous evidence for an administration of this insulin analogue. For the determination of surreptitious Levemir or recombinant human insulin applications, an unequivocal argument was not detected, but promising approaches based on a modified insulin degradation profile with altered relative intensities of metabolites are presented.
authors.affiliation: Center for Preventive Doping Research and Institute of Biochemistry, German Sport University Cologne, Carl-Diem Weg 6, 50933 Cologne, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Thomas
authors.forename: Mario
authors.initials: M
authors.lastname: Thevis
authors.forename: Philippe
authors.initials: P
authors.lastname: Delahaut
authors.forename: Alain
authors.initials: A
authors.lastname: Bosseloir
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schänzer
mesh_terms: D000595:Amino Acid Sequence; D004300:Doping in Sports / Q000331:legislation & jurisprudence; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives / Q000737:chemistry* / Q000652:urine*; D008969:Molecular Sequence Data; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors; D014556:Urine / Q000737:chemistry*
chemical_list: D007328:Insulin