title: Indirect enantioseparation of fluoxetine in mouse serum by derivatization with 1R-(-)-menthyl chloroformate followed by ultra high performance liquid chromatography and quadrupole time-of-flight mass spectrometry.
abstract: Here we describe a simple and sensitive analytical method for the enantioselective quantification of fluoxetine in mouse serum using ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry. The sample preparation method included a simple deproteinization with acetonitrile in 50 μL of serum, followed by derivatization of the extracts in 50 μL of 2 mM 1R-(-)-menthyl chloroformate at 45ºC for 55 min. These conditions were statistically optimized through response surface methodology using a central composite design. Under the optimized conditions, neither racemization nor kinetic resolution occurred. The derivatized diastereomers were readily resolved on a conventional sub-2 μm C18 column under a simple gradient elution of aqueous methanol containing 0.1% formic acid. The established method was validated and found to be linear, precise, and accurate over the concentration range of 5.0-1000.0 ng/mL for both R and S enantiomers (r(2) > 0.993). Stability tests of the prepared samples at three different concentration levels showed that the R- and S-fluoxetine derivatives were relatively stable for 48 h. No significant matrix effects were observed. Last, the developed method was successfully used for enantiomeric analysis of real serum samples collected at a number of time points from mice administered with racemic fluoxetine.
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Shin
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Jeong
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Jeongmi
authors.initials: J
authors.lastname: Lee
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D005473:Fluoxetine / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification*; D005561:Formates / Q000737:chemistry*; D007274:Injections, Intraperitoneal; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008813:Mice, Inbred ICR; D015394:Molecular Structure; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: D005561:Formates; D005473:Fluoxetine; C059663:menthyl chloroformate
keywords: Chiral derivatization reagent; Enantioseparation; Fluoxetine; Menthyl chloroformate; Response surface methodology