Selective separation of Light green and Safranin O from aqueous solution using Salvadora persica (Miswak) powder as a new biosorbent

AbstractIn this paper a novel solid phase extraction method to remove Light green (acid dye) and Safranin O (basic dye) using Salvadora persica (Miswak) powder as a new biosorbent is described. The adsorption conditions such as contact time, initial dye concentration, pH and temperature were studied by using batch system. After optimization, Miswak showed an excellent removal rate for dyes, the extraction of the dyes was accomplished in a period range of 1–10min. The adsorption kinetics data were in good agreement with the pseudo-second-order rate model (R2=0.98) and the initial sorption rate (h) was found to be 0.01gmmol−1min−1. The new adsorbent was found to have a maximum adsorption capacity of 17.3mmol/g. The adsorption isotherms could be adequately described by the Freundlich equation (R2=0.91) and the 1/n value is 0.9, which attributed to the heterogeneous surface structure of the Miswak. Study of the variation of the sorption of the tested dyes with temperature yielded values for ΔH, ΔS, and ΔG of −21.0, −0.056.3 and −4.2kJmol−1, respectively

Portable system of programmable syringe pump with potentiometer for determination of promethazine in pharmaceutical applications

AbstractA simple and fast-automated method was developed and validated for the assay of promethazine hydrochloride in pharmaceutical formulations, based on the oxidation of promethazine by cerium in an acidic medium. A portable system, consisting of a programmable syringe pump connected to a potentiometer, was constructed. The developed change in potential during promethazine oxidation was monitored. The related optimum working conditions, such as supporting electrolyte concentration, cerium(IV) concentration and flow rate were optimized. The proposed method was successfully applied to pharmaceutical samples as well as synthetic ones. The obtained results were realized by the official British pharmacopoeia (BP) method and comparable results were obtained. The obtained t-value indicates no significant differences between the results of the proposed and BP methods, with the advantages of the proposed method being simple, sensitive and cost effective