Speciation analysis of inorganic selenium in food and water samples utilizing a 2,3-diaminonaphthalene post-synthetic modified magnetic metal–organic framework.

[Display omitted] • A 2,3-diaminonaphthalene post-synthetic modified magnetic MOF was fabricated. • The material was applied to the selective extraction of inorganic selenium. • The material exhibited selectivity toward Se(IV) at a pH of 2.5. • LOD and linear range were 8.0 ng/L and 25–8000 ng/L, respectively. • The analytical applicability was confirmed in various food, and water samples. In this work, a 2,3-diaminonaphthalene post-synthetic modified magnetic metal–organic framework was fabricated for fast and selective determination of inorganic selenium in real food and water samples. The results exhibited that selenium (IV) is adsorbed by the nano-material at a pH of 2.5, and in this way, selenium (IV) can be quantified selectively. After identifying the nanosorbent with FT-IR, CHNS, XRD, SEM, TEM, VSM, and BET surface analysis, parameters affecting the retention and desorption were optimized. Under optimal conditions, the detection limit of 8 ng/L was achieved for selenium (IV), and the method's precisions were less than 12.5 % intra-day RSD% and < 14.4 % for inter-day RSD%. The highest adsorption capacity was obtained as 264 mg/g. Finally, the desired adsorbent was used to extract and determine selenium species in water samples and total selenium in food samples. One of the most important advantages of the present method is its speed, ease, time-saving, and high accuracy. [ABSTRACT FROM AUTHOR]