Arduino-Based Paired Emitter-Detector Diode Photometer for the Sensitive Determination of Cobalt following Thin Film Microextraction Using a Polymer Inclusion Membrane

Abstract

A simple, cheap, and portable Arduino-based photometer was constructed and used to determine cobalt(II) after extraction by a thin film microextraction strip. The paired emitter-detector diodes configuration was employed for making the photometer. A polymer inclusion membrane was applied to fabricate the thin film microextraction strip. The optimization of the polymer membrane composition was done by response surface methodology (RSM). The optimized membrane was obtained containing 40.8% (w/w) of polyvinyl chloride, 45.0% of (2-ethylhexyl) phosphoric acid extractor, 1.3% of 1-(2-pyridylazo)-2-naphthol as the complexing agent and 12.9% of tri-butyl phosphate plasticizer. The variables affecting microextraction efficiency were optimized to be 0.05 M of sodium sulfate, pH 6.0, and extraction time of 120 min at room temperature (22 ± 1 °C). The analytical performance included a linear range between 3 and 200 µg L⁻¹ with detection and quantitation limits of 1 and 3 µg L⁻¹, respectively. The intra-day and inter-day precision were less than 2.9 and 6.2%, respectively. Finally, the method was used to determine cobalt in the water and tablets. Relative recovery for the tap water sample was from 94 to 111%.

Keywords:

• Arduino-based photometer
• cobalt(II)
• polymer inclusion membrane
• response surface methodology (RSM)
• thin film microextraction

Acknowledgment

The authors are grateful to the research council of the University of Zanjan for the financial support of this project.

Disclosure statement

No potential conflict of interest was reported by the author(s).