title: LC-MS/MS quantification of salvinorin A from biological fluids.
abstract: A facile method for quantifying the concentration of the powerful and widely available hallucinogen salvinorin A (a selective kappa opioid agonist) from non-human primate cerebrospinal fluid (CSF) and human plasma has been developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization (ESI) mode. With CSF solid phase extraction can be avoided completely by simply diluting each sample to 10 % (v/v) acetonitrile, 1 % (v/v) formic acid and injecting under high aqueous conditions for analyte focusing. Extensive plasma sample preparation was investigated including protein precipitation, SPE column selection, and plasma particulate removal. Human plasma samples were centrifuged at 21,000 × gravity for 4 minutes to obtain clear particulate-free plasma, from which 300 μl was spiked with internal standard and loaded onto a C18SPE column with a 100 mg mL-1loading capacity. Guard columns (C18,hand packed 1 mm × 20 mm) were exchanged after backpressure increased above 4600psi, about 250 injections. A shallow acetonitrile/water gradient was used, 29 to 33% CH3CN over 8 minutes to elute salvinorin A. Reduction of chemical noise was achieved using tandem mass spectrometry with multiple reaction monitoring while sensitivity increases were observed using a 50 μL injection volume onto a small bore analytical column (C18,1 mm ID × 50 mm) thus increasing peak concentration. Limits of quantification were found to be 0.0125 ng mL-1(CSF) and 0.05 ng mL-1(plasma) with interday precision and accuracy below 1.7 % and 9.42 % (CSF) and 3.47 % and 12.37 % (plasma) respectively. This method was used to determine the concentration of salvinorin A from anin vivoRhesus monkey study and a trial of healthy human research participants, using behaviorally active doses.
authors.affiliation: Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Caspers
authors.affiliation: Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Todd D
authors.initials: TD
authors.lastname: Williams
authors.affiliation: Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Lovell
authors.affiliation: Division of Medicinal & Natural Products Chemistry, University of Iowa, Iowa City, Iowa 52242, United States.
authors.forename: Anthony
authors.initials: A
authors.lastname: Lozama
authors.affiliation: The Rockefeller University, New York, New York 10065, United States.
authors.forename: Eduardo R
authors.initials: ER
authors.lastname: Butelman
authors.affiliation: The Rockefeller University, New York, New York 10065, United States.
authors.forename: Mary Jeanne
authors.initials: MJ
authors.lastname: Kreek
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, United States.
authors.forename: Roland
authors.initials: R
authors.lastname: Griffiths
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, United States.
authors.forename: Katherine
authors.initials: K
authors.lastname: Maclean
authors.affiliation: Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Prisinzano