Au nanoparticle grafted thiol modified magnetic nanoparticle solid phase extraction coupled with high performance liquid chromatography for determination of steroid hormones in human plasma and urine

Abstract

A new, simple, rapid and sensitive preconcentration method was developed for separation of two neutral steroids (progesterone and testosterone) through an off-line extraction/preconcentration procedure using Au nanoparticles grafted on a 3-(trimethoxysilyl)-1-propanethiol modified magnetic nanoparticle adsorbent prior to their determination by HPLC-UV. The preconcentration step was optimized by a comprehensive study on the main factors affecting the extraction/preconcentration efficiency of the steroids such as pH value, amount of surfactant, amount of magnetic adsorbent, sample volume, desorption conditions and ionic strength. The validity of the method was investigated and good analytical performance was obtained including a wide dynamic range of 0.1–200 ng mL⁻¹, low detection limits of 0.05 and 0.07 ng mL⁻¹, and good precision (as RSD%) lower than 3.90 and 4.19% for progesterone and testosterone, respectively. The method was applied to determine the steroidal hormones in human plasma and urine samples. The levels were found to be 0.8 and 9.2 ng mL⁻¹ for progesterone and 7.9 and 97.5 ng mL⁻¹ for testosterone in plasma and urine samples, respectively, which are within the normal range reported in the literature.