title: Use of fast HPLC multiple reaction monitoring cubed for endogenous retinoic acid quantification in complex matrices.
abstract: Retinoic acid (RA), an essential active metabolite of vitamin A, controls numerous physiological processes. In addition to the analytical challenges owing to its geometric isomers, low endogenous abundance, and often localized occurrence, nonspecific interferences observed during liquid chromatography (LC) multiple reaction monitoring (MRM) quantification methods have necessitated lengthy chromatography to obtain accurate quantification free of interferences. We report the development and validation of a fast high performance liquid chromatography (HPLC) multiplexing multiple reaction monitoring cubed (MRM(3)) assay for selective and sensitive quantification of endogenous RA from complex matrices. The fast HPLC separation was achieved using an embedded amide C18 column packed with 2.7 μm fused-core particles which provided baseline resolution of endogenous RA isomers (all-trans-RA, 9-cis-RA, 13-cis-RA, and 9,13-di-cis-RA) and demonstrated significant improvements in chromatographic efficiency compared to porous particle stationary phases. Multiplexing technology further enhanced sample throughput by a factor of 2 by synchronizing parallel HPLC systems to a single mass spectrometer. The fast HPLC multiplexing MRM(3) assay demonstrated enhanced selectivity for endogenous RA quantification in complex matrices and had comparable analytical performance to robust, validated LC-MRM methodology for RA quantification. The quantification of endogenous RA using the described assay was validated on a number of mouse tissues, nonhuman primate tissues, and human plasma samples. The combined integration of fast HPLC, MRM(3), and multiplexing yields an analysis workflow for essential low-abundance endogenous metabolites that has enhanced selectivity in complex matrices and increased throughput that will be useful in efficiently interrogating the biological role of RA in larger study populations.
authors.affiliation: University of Maryland, School of Pharmacy, Department of Pharmaceutical Sciences, 20 N. Pine Street, Baltimore, Maryland 21201, United States.
authors.forename: Jace W
authors.initials: JW
authors.lastname: Jones
authors.affiliation: University of Maryland, School of Pharmacy, Department of Pharmaceutical Sciences, 20 N. Pine Street, Baltimore, Maryland 21201, United States.
authors.forename: Keely
authors.initials: K
authors.lastname: Pierzchalski
authors.affiliation: University of Maryland, School of Pharmacy, Department of Pharmaceutical Sciences, 20 N. Pine Street, Baltimore, Maryland 21201, United States.
authors.forename: Jianshi
authors.initials: J
authors.lastname: Yu
authors.affiliation: University of Maryland, School of Pharmacy, Department of Pharmaceutical Sciences, 20 N. Pine Street, Baltimore, Maryland 21201, United States.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Kane
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007536:Isomerism; D057230:Limit of Detection; D013058:Mass Spectrometry; D051379:Mice; D013997:Time Factors; D014212:Tretinoin / Q000032:analysis* / Q000097:blood / Q000737:chemistry
chemical_list: D014212:Tretinoin