extraction and determination of three steroid molecules in milk using functionalized magnetic carbon nanotube-based solid phase extraction coupled with hplc

A new magnetic carbon nanotube-based strontium-titanium (fe/cnt-srtio3) adsorbent was synthesized to extract two steroid hormones (17β-estradiol and progesterone) and a synthetic derivative of estradiol (ethinyl estradiol) from milk in an optimized mspe-hplc method. the proposed adsorbent was characterized using ft-ir, bet, fesem, tem, and xrd techniques. under optimized extraction parameters (effects of strontium-titanium dosage, desorbing solvent, adsorbent amount, solvent and sample volumes, adsorption and desorption times, salt percentage, and ph value) and matrix-matched calibration, a decent linear dynamic range was obtained 1–1000 ng ml−1 for all three hormones with acceptable relative standard deviation percentages of 1.49–2.31. the limits of detection (s/n = 3, n = 3) and quantitation (s/n = 10, n = 3) for the analytes were respectively in the range of 0.033–0.34 and 0.11–1.14 ng ml−1. the proposed method provided acceptable precision based on intra-day (rsd range of 1.47–2.31%, n = 3) and inter-day (rsd range of 1.75–4.54%, n = 9) experiments. real sample analysis was conducted using the same method to determine the concentration of hormones in three milk samples with related recovery percentages of 60.2–113.49. the results showed that the novel adsorbent could be used as an alternative material for hormone extraction in different biological fluids.