Determining the Endpoint of Sediment Titrations by Smartphones

Abstract

In this research work, we have used the image processing technique for determining the end of sodium sulphate with standard barium chloride in precipitation titration. The white precipitate of barium sulphate produced by the reaction of barium chloride and sodium sulphate was dispersed in deionized water by magnetic stirrer and its images were taken by mobile phone camera. The resulting pictures were analyzed by Photoshop Software which shows that the intensity of magenta colour has maximum sensitivity by changing the mass of barium sulphate. Therefore; magenta colour was selected as the optimum colour. Also, to depict the calibration curve of sulphate anion, different concentrations of sulphate were prepared in buffered solutions and by addition of barium chloride to them, the intensity of magenta colour was calculated. The results show that the calibration curve was linear in the range of 5-75 mg.L -1 of sulpahte with a correlation coefficient of 0.973. Finally, by titration of different real samples such as Tap, river and mineral waters containing sulphate anion with standard barium chloride, the variation of magenta colour was recorded and the concentration of sulpahte anion was determined.