Optimisation of Arsenic (III) by Colorimetric Incorporated with Image Processing Technique

Abstract

Inorganic arsenic contamination has caused a remarkable impact on the contamination of soil and groundwater in many countries. Consequently, determination of inorganic arsenic on site is very crucial especially arsenic (III) which is more toxic than arsenic (V). Thus, a more rapid, simple and ecofriendly approach was developed in this study to determine arsenic (III) by incorporation of image processing technique into colorimetric method. The effects of various factors were evaluated by a 2 4 full factorial design with a blocking factor. The mass ratio of sulfamic acid to zinc powder was the most significant factor affected red, green and blue (RGB) color values and followed by reaction period. The optimum conditions for the detection were found to be using 1 g of sulfamic acid and 0.5 g of zinc powder at 5 minutes. This work also demonstrates that the developed method is able to detect arsenic (III) rapidly and easily.

Digital Image-Based Colorimetry for Enhancement of Arsenic(III) Determination

“…Coloured compound formation: The detection of various concentrations (0 to 300 µg/L) of As(III) was performed in five replications at the optimum conditions as reported by Leong et al [9] in order to develop a mathematical model for the estimation of concentrations of As(III) in water samples. Briefly, the optimum amount of sulfamic acid was added to a 60 mL of polypropylene bottle which contained 50 mL of As(III) working standard solution.…”

“…Colour image processing: The image processing of the captured images were performed using the method as described by Leong et al [9] where colour images were captured by a digital camera (Sony Cyber-shot, DSC-W610) at the distance of 15 cm at constant conditions for all experiments. The images were transformed into Red, Green and Blue (RGB) colour values (0 to 225) using Image J software and subsequently used for mathematical modelling and statistical analysis.…”