title: Simultaneous quantification and qualification of synacthen in plasma.
abstract: Tetracosactide (Synacthen), a synthetic analogue of adrenocorticotropic hormone (ACTH), can be used as a doping agent to increase the secretion of glucocorticoids by adrenal glands. The only published method for anti-doping control of this drug in plasma relies on purification by immunoaffinity chromatography and LC/MS/MS analysis. Its limit of detection is 300 pg/mL, which corresponds to the peak value observed 12 h after 1 mg Synacthen IM administration. We report here a more sensitive method based on preparation of plasma by cation exchange chromatography and solid-phase extraction and analysis by LC/MS/MS with positive-mode electrospray ionization using 7-38 ACTH as internal standard. Identification of Synacthen was performed using two product ions, m/z 671.5 and m/z 223.0, from the parent [M + 5H](5+) ion, m/z 587.4. The recovery was estimated at 70%. A linear calibration curve was obtained from 25 to 600 pg/mL (R² > 0.99). The lower limit of detection was 8 pg/mL (S/N > 3). The lower limit of quantification was 15 pg/mL (S/N > 10; CV% < 20%). The performance of the method was illustrated by an 8-h kinetic analysis of plasma samples from nine subjects submitted to IM injections of either Synacthen® (five subjects) or Synacthen® Depot, the slow-release form of the drug (four subjects). Concentrations of Synacthen between 16 and 310 pg/mL were observed. A sensitive method for quantitation of Synacthen in plasma is proposed for anti-doping control analyses.
authors.affiliation: Département des Analyses, Agence Française de Lutte contre le Dopage (afld), 143, avenue Roger Salengro, Châtenay-Malabry, 92290 Paris, France.
authors.forename: Ayman
authors.initials: A
authors.lastname: Chaabo
authors.forename: Jacques
authors.initials: J
authors.lastname: de Ceaurriz
authors.forename: Corinne
authors.initials: C
authors.lastname: Buisson
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Tabet
authors.forename: Françoise
authors.initials: F
authors.lastname: Lasne
mesh_terms: D002852:Chromatography, Ion Exchange; D002853:Chromatography, Liquid; D003366:Cosyntropin / Q000097:blood*; D006801:Humans; D013058:Mass Spectrometry; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction
chemical_list: D003366:Cosyntropin