Selective and sensitive method for the determination of metoprolol in human plasma using liquid chromatography coupled with tandem mass spectrometry.

A high-performance liquid chromatography-tandem mass spectrometric method was developed and validated for the determination of metoprolol in human plasma. The analyte and internal standard, nevirapine, were extracted from plasma matrix by liquid-liquid extraction with ethyl acetate. Chromatographic separation was achieved on a C-18 analytical column with an isocratic mobile phase of 15:85 (V/V) 10 mmol L-1 ammonium acetate (pH 5.

Removal of mercury from aqueous solutions using activated carbon prepared from agricultural by-product/waste.

Removal of mercury from aqueous solutions using activated carbon prepared from Ceiba pentandra hulls, Phaseolus aureus hulls and Cicer arietinum waste was investigated. The influence of various parameters such as effect of pH, contact time, initial metal ion concentration and adsorbent dose for the removal of mercury was studied using a batch process. The experiments demonstrated that the adsorption process corresponds to the pseudo-second-order-kinetic models and the equilibrium adsorption data fit the Freundlich isotherm model well.