Determination of testosterone/epitestosterone concentration ratio in human urine by capillary electrophoresis.

A novel method for determining the testosterone/epitestosterone concentration ratio in human urine was established by capillary electrophoresis with diode-array detector. The urine samples were firstly purified by the solid extraction. The optimal experimental conditions were: running buffer pH = 4.74, 15.0 mmol L-1 HAc-NaAc, separation voltage 25 kV, temperature 25 °C, sample injection pressure 3.43 × 103 Pa, and duration 10 s. The testosterone and epitestosterone linear range were determined as 8.0-960.0 ng mL-1, respectively. The testosterone and epitestosterone detection limits were determined as 4.6 and 4.5 ng mL-1, respectively. The relative standard deviation was less than 0.36%.

Mxene/alginate composites for lead and copper ion removal from aqueous solutions.

Mxene has been widely used as a sorbent to remove heavy metal ions from sewage due to its unique two-dimensional layered structure and abundant oxygen-containing groups. However, Mxene has a relatively limited adsorption capacity for metal ions possibly due to the limited adsorption active sites. Herein, we reported novel Mxene/alginate composites for lead and copper ion removal from wastewater. The Mxene/alginate composites prepared in this study not only enhance the chelation ability of the lead and copper ions, but also accelerate the ion transport efficiency. The combined advantages of high adsorption capacity and short equilibrium time enable the Mxene/alginate composites to achieve the maximum adsorption capacity for Pb2+ and Cu2+ at 382.7 and 87.6 mg g-1, respectively, and reach the adsorption equilibrium in 15 min. We believe that the composites developed in this study can open a new avenue for designing high adsorption capacity and high efficiency adsorbents.