title: Development of a QuEChERS-Based Stable-Isotope Dilution LC-MS/MS Method To Quantitate Ferulic Acid and Its Main Microbial and Hepatic Metabolites in Milk.
abstract: Forage plants of the Poaceae family are grown as pasturage or used for the production of hay, straw, corn stover, etc. Although ferulic acid contents of grasses are generally high, the amount of ingested ferulic acid differs depending on the type of forage, resulting in varying contents of ferulic acid and its microbial and hepatic metabolites in milk. Concentrations and patterns of these metabolites may be used as markers to track different forages in livestock feeding. Therefore, we developed a stable isotope dilution assay to quantitate ferulic acid, 12 ferulic acid-based metabolites, p-coumaric acid, and cinnamic acid in milk. Because most analytes were not commercially available as stable isotope labeled standard compounds, they were synthesized as13C- or deuterium-labeled standard compounds. A modification of the QuEChERS method, a Quick, Easy, Cheap, Effective, Rugged, and Safe approach usually applied to analyze pesticides in plant-based products, was used to extract the phenolic acids from milk. Determination was carried out by LC-ESI-MS/MS in scheduled multiple reaction monitoring modus. By using three different milk samples, the applicability of the validated approach was demonstrated.
authors.affiliation: Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Waterstraat
authors.affiliation: Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hildebrand
authors.affiliation: Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Margit
authors.initials: M
authors.lastname: Rosler
authors.affiliation: Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Bunzel
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis; D002417:Cattle; D005591:Chemical Fractionation / Q000379:methods*; D003373:Coumaric Acids / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D003903:Deuterium / Q000032:analysis; D008099:Liver / Q000378:metabolism*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D053719:Tandem Mass Spectrometry
chemical_list: D002247:Carbon Isotopes; D003373:Coumaric Acids; D003903:Deuterium; C004999:ferulic acid
keywords: QuEChERS; ferulic acid; hydroxycinnamic acids; isotopic labeling; mass spectrometry; metabolism; milk; phenolic acids; stable isotope dilution assay