UV–vis spectrophotometer and smartphone RGB dual mode detection of inorganic arsenic based on hydride generation iodine–starch system

[Display omitted] •Hydride generation was utilized as a gaseous sampling technique for the iodine–starch colorimetric analytical system with interferences eliminated.•UV–vis spectrophotometer and smartphone RGB dual mode analytical system was established for the detection of As(III).•Smartphone was used as a portable analytical device for RGB readout.•The proposed method was successful applied to three certified reference water samples and three water samples, with good recoveries of 94%–108%. A dual-mode analytical system based on hydride generation iodine–starch was established for the inorganic arsenic detection by UV–vis spectrophotometer and smartphone RGB. Hydride generation (HG) was used as a gaseous sample introduction technique for this dual-mode analytical system, the generated AsH3 was transported into iodine–starch solution, so that the color of iodine–starch solution was faded from dark blue to colorless, which could be recorded by UV–vis spectrophotometer and smartphone RGB simultaneously. Various experimental conditions were investigated, three certified reference water samples, three water samples and its spiked samples were detected by this dual mode analytical system under the optimized conditions, recoveries ranging 94–108 % were obtained, indicating a good accuracy and applicability of this method. A detectable concentration as low as 0.01 μg mL−1 was achieved, meeting the analysis requirement of As(III) in water samples. It is a potential analytical system for inorganic arsenic detection in field analysis.