Original Articles
Ruchi Dubey Sharma, Smita Josh
Abstract
A new optical analytical method, “digital RGB Analysis” is proposed instead of the conventional optical method, “spectrophotometry”. MATLAB image processing tool can transform the color information into digital RGB values that can be treated as analytical information. The tool can simulate the color variations by optimization of visual color sensor with computer assistance and thus make colorimetry (semi quantitative analysis) as an accurate determination method. The Paper optode has been prepared by immobilizing potassium iodide (KI) and starch on thin layer chromatographic (TLC) strip. The reaction is based on indirect determination of lead by determining iodine liberated which results into blue colored spot; followed by scanner based detection. The obtained pattern was analyzed using image processing tool of MATLAB software to determine lead. All parameters affecting intensity on optode have been optimized. The proposed sensor was linear in the range 0.024-12µg mL-1 {24 µL of 1-500 µg mL-1 (R2=0.998)} for G and B values. The minimum detection limit was found 3ng mL-1(6µL of 5 µg mL-1).The proportionality in intensity of the spot color on the optodes loaded with varying amounts of lead suggests its potential applications for screening of lead. The paptode can be used for health check and pollutant check at home. Thus the paper optode has great potential for this purpose.