Synthesis and application of magnetic bio-sorbent for determination trace amounts of thymol

A reliable and sensitive method was developed for the determination of thymol by magnetic dispersive micro-solid phase extraction (MD-µSPE) based on the use of Escherichia coli bacteria. It was immobilized on the γ-Fe۲O۳ magnetic nanoparticles and used as a bio-sorbent for MD-µSPE. The properties of the synthesized bio-sorbent were characterized by Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX), and field emission scanning electron microscopy (FE-SEM). Central composite design (CCD) combined with desirability function approach was applied to search for optimal operational conditions. Under the optimum conditions specified as: ۲۵ min ultrasonic time, pH=۵, ۳۰ mg of bio-adsorbent, and temperature ۳۵ °C, high and reasonable linear range over ۳۰ - ۵۰۰ ng mL-۱ (R۲ > ۰.۹۹۶۵) with limit of detection (LOD) ۹.۱۸۳ ng mL−۱ were obtained. Finally, the proposed method was successfully used for extraction and determination of thymol in food and cosmetic samples

Keywords:

Thymol , Biosorption , Escherichia coli , Central composite design , Food and cosmetic samples.