title: Analysis of selective androgen receptor modulators by gas chromatography-microchip atmospheric pressure photoionization-mass spectrometry.
abstract: A gas chromatography-microchip atmospheric pressure photoionization-mass spectrometric (GC-microAPPI-MS) method was developed and used for the analysis of three 2-quinolinone-derived selective androgen receptor modulators (SARMs). SARMs were analyzed from spiked urine samples, which were hydrolyzed and derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide before analysis. Trimethylsilyl derivatives of SARMs formed both radical cations (M(+*)) and protonated molecules ([M + H](+)) in photoionization. Better signal-to-noise ratios (S/N) were obtained in MS/MS analysis using the M(+*) ions as precursor ions than using the [M + H](+) ions, and therefore the M(+*) ions were selected for the precursor ions in selected reaction monitoring (SRM) analysis. Limits of detection (LODs) with the method ranged from 0.01 to 1 ng/mL, which correspond to instrumental LODs of 0.2-20 pg. Limits of quantitation ranged from 0.03 to 3 ng/mL. The mass spectrometric response to the analytes was linear (R > or = 0.995) from the LOQ concentration level up to 100 ng/mL concentration, and intra-day repeatabilities were 5%-9%. In addition to the GC-microAPPI-MS study, the proof-of-principle of gas chromatography-microchip atmospheric pressure chemical ionization-Orbitrap MS (GC-microAPCI-Orbitrap MS) was demonstrated.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Helsinki, Finland. laura.luosujarvi@helsinki.fi
authors.forename: Laura
authors.initials: L
authors.lastname: Luosujärvi
authors.forename: Markus
authors.initials: M
authors.lastname: Haapala
authors.forename: Mario
authors.initials: M
authors.lastname: Thevis
authors.forename: Ville
authors.initials: V
authors.lastname: Saarela
authors.forename: Sami
authors.initials: S
authors.lastname: Franssila
authors.forename: Raimo A
authors.initials: RA
authors.lastname: Ketola
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
authors.forename: Tapio
authors.initials: T
authors.lastname: Kotiaho
mesh_terms: D045930:Anabolic Agents / Q000032:analysis; D059002:Androgen Receptor Antagonists; D000728:Androgens; D001274:Atmospheric Pressure; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006727:Hormone Antagonists / Q000032:analysis* / Q000652:urine; D006801:Humans; D046208:Microchip Analytical Procedures / Q000379:methods*; D010777:Photochemistry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D045930:Anabolic Agents; D059002:Androgen Receptor Antagonists; D000728:Androgens; D006727:Hormone Antagonists