Derivatization and Separation of Natural Estrogens (estrone, 17β-estradiol, and estriol) Using Gas Chromatography with Flame Ionization Detection (GC-FID)
A major cause of concern for estrogens found in the environment is that even at very low concentrations (10-100 ng/L) they can have a negative effect on aquatic ecosystems by disrupting endocrine systems. Due to the increasing importance of monitoring the levels of estrogens in the environment, a detection method was developed to identify and quantify three natural estrogens (estrone, 17β-estradiol and estriol) using gas chromatography with flame ionization detection (GC-FID). In addition, the efficacy of two derivatizing agents, N,O-bis(trimethylsilyl) acetamide (BSTA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), was evaluated. The GC detector (FID) was most responsive with E3, followed by E1 and E2. The lowest concentration detected in this study was 0.1 ng/μL for E1 and 1.0 ng/μL for E2. E3 was detectable at the lowest concentration examined (0.01 ng/μL) and is likely detectable at a much lower concentration. The response of the GC-FID to all three estrogens was linear from 0.01-100 ng/μL. The data suggest also that both derivatizing agents are effective for the three natural estrogens. This analytical method will be used in future studies to detect and quantify natural estrogens from environmental samples, and will be particularly useful when exploring the relative concentration of various estrogen compounds spatially and/or temporally
