title: Measurement of Estradiol in Human Serum by LC-MS/MS Using a Novel Estrogen-Specific Derivatization Reagent.
abstract: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described that employs a novel derivatization reagent for the measurement of serum estradiol (E2), with simultaneous analysis of underivatized testosterone (T) and dihydrotestosterone (DHT). The main advantage of the new derivatization reagent 1,2-dimethylimidazole-5-sulfonyl chloride is its analyte-specific fragmentation that enables monitoring of confirmatory mass transitions with high sensitivity. The reaction mixture can be analyzed without additional purification steps using a 9.5 min gradient run, and sensitive detection is achieved with a triple quadrupole mass spectrometer using atmospheric pressure photoionization. Method validation was performed with human serum samples, including a comparison with a standard LC-MS/MS method using 120 samples from a clinical study, and analysis of certified E2 serum reference materials BCR-576, BCR-577, and BCR-578. The lower limits of quantification for E2, T, and DHT were 0.5 pg/mL, 25 pg/mL, and 0.10 ng/mL, respectively, from a 200-μL sample. Validation results indicated good accuracy and agreement with established, conventional LC-MS/MS assays, demonstrating suitability for analysis of samples containing E2 in the low pg/mL range, such as serum from men, children, and postmenopausal women.
authors.affiliation: †ANZAC Research Institute, University of Sydney and Andrology Department, Concord Hospital, NSW Health, Sydney, NSW 2139, Australia.
authors.forename: Pekka
authors.initials: P
authors.lastname: Keski-Rahkonen
authors.affiliation: †ANZAC Research Institute, University of Sydney and Andrology Department, Concord Hospital, NSW Health, Sydney, NSW 2139, Australia.
authors.forename: Reena
authors.initials: R
authors.lastname: Desai
authors.affiliation: †ANZAC Research Institute, University of Sydney and Andrology Department, Concord Hospital, NSW Health, Sydney, NSW 2139, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Jimenez
authors.affiliation: †ANZAC Research Institute, University of Sydney and Andrology Department, Concord Hospital, NSW Health, Sydney, NSW 2139, Australia.
authors.forename: D Tim
authors.initials: DT
authors.lastname: Harwood
authors.affiliation: †ANZAC Research Institute, University of Sydney and Andrology Department, Concord Hospital, NSW Health, Sydney, NSW 2139, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004958:Estradiol / Q000097:blood* / Q000737:chemistry; D004967:Estrogens / Q000097:blood*; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry*; D015394:Molecular Structure; D013441:Sulfinic Acids / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D004967:Estrogens; D007202:Indicators and Reagents; D013441:Sulfinic Acids; D004958:Estradiol; C044255:sulfonyl chloride