title: Quantitative determination of 26 steroids in eggs from various species using liquid chromatography-triple quadrupole-mass spectrometry.
abstract: A method for analyzing 26 types of steroids in egg matrix was developed. The method used liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in electrospray ionization mode (ESI). The procedure involved extraction with acetonitrile and removal of phospholipids by zinc chloride (ZnCl₂) followed by SPE cleanup with a Plexa cartridge. The effect of ZnCl₂ on phospholipid removal was directly observed using the post column infusion procedure. The SPE washing and elution conditions were optimized using a shallow gradient procedure. The free and conjugated steroids forms were determined using enzyme hydrolysis. The developed method resulted in satisfactory precision (RSD≤15%), and the limits of quantification were between 0.05 and 25 ng/g depending on the steroid types. The recoveries ranged from 63.2% to 121.5%. Finally, the developed method was successfully applied to compare the steroids in eggs from different species (i.e., hen, duck, quail and pigeon eggs) or different raising system (i.e., normal vs. organic eggs). The steroids can be clearly clustered according to species and raising system. The hierarchical clustering analysis indicated similarity of the steroids among the species. The developed method is sensitive and useful for detection and quantification of steroids in eggs and can be used for residue control programs. In addition, the observed steroid content will provide a fundamental reference for food risk assessment analysis.
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Mi
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Sicong
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Kaiqiang
authors.initials: K
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Agro-product Quality and Safety, Institute of Quality Standards & Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. Electronic address: chengang01@caas.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D000731:Androstanes / Q000737:chemistry / Q000302:isolation & purification*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D010856:Columbidae; D004372:Ducks; D004531:Eggs / Q000032:analysis*; D005260:Female; D005504:Food Analysis / Q000379:methods*; D006728:Hormones / Q000737:chemistry / Q000302:isolation & purification*; D006868:Hydrolysis; D057230:Limit of Detection; D011278:Pregnanes / Q000737:chemistry / Q000302:isolation & purification*; D011784:Quail; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000731:Androstanes; D006728:Hormones; D011278:Pregnanes
keywords: Eggs; Liquid chromatography–tandem mass spectrometry; Principal component analysis; Steroids