Abstract
Background Very sensitive measurements of serum estrogens and testosterone are important in adult and pediatric endocrinology and immunoassays are known to lack the required performance at very low levels. Our aim was to develop a sensitive HPLC–MS/MS assay for both estradiol (E2) and testosterone (Te) in serum without the need for chemical derivatization and using commercially available calibrators. Methods Serum samples were prepared by the addition of internal standards followed by extraction using hexane:ethyl acetate. Chromatographic separation was achieved using a C18 column and mass spectrometry was performed in both positive and negative ion modes. Results The lower limits of quantitation (LLOQs) of E2 and Te were 5 pg/mL and 1 ng/dL, respectively. The analytical measurement range (AMR) for E2 was 5–600 pg/mL and 1–1,170 ng/dL for Te. Assay accuracy was determined both by comparison with a LC–MS/MS method performed at a national laboratory and the CDC HoSt program. Comparison with samples analyzed by both methods showed excellent correlation. Within-day (N = 10) and between-day (N = 20) CVs at concentrations spanning the AMR were less than 7% for both analytes. Conclusion We have developed an accurate and highly sensitive assay to measure E2 and Te levels in serum by HPLC–MS/MS without chemical derivatization and using commercially available calibrators.
Original language | English (US) |
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Pages (from-to) | 70-76 |
Number of pages | 7 |
Journal | Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences |
Volume | 1048 |
DOIs | |
State | Published - Mar 24 2017 |
Keywords
- CDC HoSt
- Estradiol
- Liquid chromatography
- Mass spectrometry
- Method correlation
- NIST SRM 971
- Testosterone
ASJC Scopus subject areas
- Analytical Chemistry
- Biochemistry
- Clinical Biochemistry
- Cell Biology