It remains an analytical challenge to quantify estrogens and their metabolites in specimens from special populations.
Estrogen levels are at pg/mL in serum or plasma samples from older men, children, postmenopausal women and women receiving aromatase inhibitors for breast cancer treatment.
Stable isotope dilution LC-SRM/MS assays provide high specificity and accuracy.
Estrogen derivatives facilitate ultra-high sensitivity LC-SRM/MS-based analysis.
Suggested practices for ultra-high sensitivity LC-SRM/MS-based methodology are reviewed
Future perspectives on the use of high-resolution mass spectrometry are discussed.