Development and validation of an analytical method for the determination of 17β-estradiol residues in muscle of tambaqui (Colossoma macropomum Cuvier, 1818) by LC-MS/MS and its application in samples from a fish sexual reversion study

Development of Analytical Procedure for the Determination of 17β-Testosterone, 11-Ketotestosterone and 17β-Estradiol in the Sea Trout (Salmo trutta L.) Gonads

Steroid hormones, such as 17β-testosterone, 11-ketotestorenone and 17β-estradiol, play an essential role not only in reproductive function but also are potential biomarkers of numerous additional functions in teleost fish. The presence of endocrine disruptor compounds in aquatic ecosystems has raised concern about their effect on hormone levels in fish target organs. Since hormones are present in very low concentrations in biological material, their determination still remains a challenge. A new analytical procedure has been developed to determine 17β-testosterone, 11-ketotestosterone and 17β-estradiol in the sea trout female and male gonads by liquid chromatography-tandem mass spectrometry (LC-MS/MS) system equipped with an ESI source operating in both positive and negative mode. Chromatographic separation of analytes was accomplished in Poroshell 120 EC-C18 (150 mm × 2.1 mm, 2.7 µm) column under isocratic elution conditions. The mobile phase consisted of acetonitrile, methanol and water (20:50:30/v/v/v) at a flow rate of 0.2 mL/min. Analytes were extracted from the gonad matrix with ethyl acetate, and co-extractives impurities were successfully removed by QuEChERS (quick, easy, cheap, effective, rugged and safe) method. The procedure was validated with good sensitivity, linearity, accuracy, and precision. Limits of quantifications were from 0.15 to 0.75 ng/g, linearity was obtained with correlation coefficient R > 0.99, accuracy was from 94.0 to 109.5%, precision expressed as RSD ranged from 1.7 to 27.2% (repeatability) and from 2.2 to 37.1% (reproducibility). Finally, the method was applied to determining 17β-testosterone, 11-ketotestosterone and 17β-estradiol in real samples of the female and male sea trout gonads, 8 and 22 samples, respectively.

Beta-Cyclodextrin-Decorated Magnetic Activated Carbon as a Sorbent for Extraction and Enrichment of Steroid Hormones (Estrone, β-Estradiol, Hydrocortisone and Progesterone) for Liquid Chromatographic Analysis

A β-cyclodextrin-decorated magnetic activated carbon adsorbent was prepared and characterized using various analytical techniques (X-ray diffraction (XRD), scanning electron microscopy–electron diffraction spectroscopy (SEM-EDS) and transmission electron microscopy (TEM)), and the adsorbent was used in the development of a magnetic solid-phase microextraction (MSPE) method for the preconcentration of estrone, β-estradiol, hydrocortisone and progesterone in wastewater and river water samples. This method was optimized using the central composite design in order to determine the experimental parameters affecting the extraction procedure. The quantification of hormones was achieved using high-performance liquid chromatography equipped with a photodiode array detector (HPLC-DAD). Under optimum conditions, the linearity ranged from 0.04 to 300 µg L⁻¹ with a correlation of determinations of 0.9969–0.9991. The limits of detection and quantification were between 0.01–0.03 and 0.033–0.1 µg L⁻¹, with intraday and interday precisions at 1.1–3.4 and 3.2–4.2. The equilibrium data were best described by the Langmuir isotherm model, and high adsorption capacities (217–294 mg g⁻¹) were obtained. The developed procedure demonstrated high potential as an effective technique for use in wastewater samples without significant interferences, and the adsorbent could be reused up to eight times.