- Improved profiling of estrogen metabolites by orbitrap LC/MS.
Improved profiling of estrogen metabolites by orbitrap LC/MS.
Steroids (2014-12-30)
Xingnan Li, Adrian A Franke
PMID25543003
ABSTRACT
Estrogen metabolites are important biomarkers to evaluate cancer risks and metabolic diseases. Due to their low physiological levels, a sensitive and accurate method is required, especially for the quantitation of unconjugated forms of endogenous steroids and their metabolites in humans. Here, we evaluated various derivatives of estrogens for improved analysis by orbitrap LC/MS in human serum samples. A new chemical derivatization reagent was applied modifying phenolic steroids to form 1-methylimidazole-2-sulfonyl adducts. The method significantly improves the sensitivity 2-100 fold by full scan MS and targeted selected ion monitoring MS over other derivatization methods including, dansyl, picolinoyl, and pyridine-3-sulfonyl products.
MATERIALS
Product Number
Brand
Product Description
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
Dansyl chloride, BioReagent, suitable for amino acid labeling, powder and chunks, ≥99% (HPLC)
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Supelco
Testosterone solution, 1.0 mg/mL in acetonitrile, ampule of 1 mL, certified reference material, Cerilliant®