Rapid Low-Cost Determination of Lead(II) in Cassava by an iPod-Based Digital Imaging Colorimeter

Abstract

An iPod-based digital image colorimeter was developed for the determination of lead(II) in cassava. The method is based on the color values of a lead(II) solution following its reaction with dithizone. Lead(II) from cassava was extracted using an ultraviolet-digestion unit followed by the color-forming reaction and image capture using the ColorConc application operated on an iPod touch. The concentration was predicted by comparing the color values with those collected in a database. The time needed for complete digestion was 30 min. The determined concentrations of lead(II) were from 0.10 to 1.00 µg mL⁻¹. The limits of detection and quantitation were 0.0120 and 0.0399 µg mL⁻¹, respectively. The recovery values were 105 ± 7.07% and 109 ± 6.61% at 0.2 µg mL⁻¹ and 0.4 µg mL⁻¹ lead(II) (n = 5). The reported method was demonstrated to be simple, accurate, rapid, precise, and low cost.

Keywords:

• Cassava
• dithizone
• iPod-based digital image colorimeter
• lead(II)

Acknowledgments

Special thanks to Department of Chemistry, Faculty of Science, Naresuan University for laboratory facilities and consumable materials and thanks to Science Achievement Scholarship of Thailand. The authors thank Asst. Prof. Dr. Filip Kielar for helpful comments and corrections of the manuscript.

Additional information

Funding

Financial support from National Research Council of Thailand via Naresuan University (in the year 2017) is gratefully acknowledged.