Dispersive solid phase extraction and preconcentration of Reactive blue194 using magnetic carbon nanotube and utilization of smart Mobile Phone for colorimetric analysis

In this work the applicability of carbon magnetic nanotubes as a magnetic solid phase sorbent for the extraction/preconcentration of Reactive Reactive Blue 194 (RB194) were studied. Carbon magnetic nanotubes were synthesized by the solvothermal method in polyol media [1]. The method utilizes the unique properties of carbon magnetic nanotubes including high surface area and superparamagnetism causing rapid separation. To optimize of important factors such as the adsorption time, NaOH concentration, adsorption pH, desorption time, amount of adsorbent and volume of eluent, central composite design method was used [2]. After extraction of RB194, the concentration of dye was determined colorimetrically with the aid of smart mobile phone. The calibration curve had two linear range of 20-200 μg L-1 and 1-10 mg L-1 of RB194. Limit of detection was 4 μg L-1. The relative standard deviations of six replicate measurements were 2.2% and 3.0% for 0.1 and 3 mg L-1 of RB194, respectively. The proposed method was used for analysis of RB194 in environmental waters and satisfactory results were obtained. The recoveries were in the range of 95–108 %.