Smartphone based colorimetric analyzer for detection of phosphate in water
This paper reports a low-cost, compact, field-portable smartphone based colorimetric analyzer for detection of phosphate concentration in water medium. A 3D printed cradle housing all the optical components is integrated with the built-in camera of the smartphone using which photographs of the reagent treated test samples are captured. Using an android application, the RGB color model is converted to the HSV color model. For the quantification of phosphate, the V-channel value of HSV color space is corelated with the phosphate concentration. The obtained results are compared with the laboratory grade standard spectrophotometer by measuring its absorbance at a specific wavelength. The designed smartphone sensing tool has an ability to measure phosphate concentration as low as 0.01 mg/L with a good accuracy (%bias <1%) and precision (RSD <2%). The sensing technique can be used as an alternative to existing phosphate level detection sensors as it provides a fast and user-friendly analysis for in-field applications.
