Selective extraction and determination of beryllium in real samples using amino-5,8-dihydroxy-1,4-naphthoquinone...

Herein, a magnetic MOF for preconcentration of Be(ii) was synthesized. The material is obtained from magnetite (Fe₃O₄) nanoparticles that were modified with 2-amino-5,8-dihydroxy-1,4-naphthoquinone (ADHNQ) and then reacted with terephthalic acid and iron(iii) chloride to form a metal-organic framework of the type MIL-53(Fe) capable of extracting Be(ii). The extraction parameters were optimized by employing design of experiments methodology. Beryllium concentration was determined by flame atomic absorption spectrometry (FAAS). The detection limit was as low as 0.07 ng mL^-1 and the quantification limit is 0.2 ng mL^-1. Linearity extends from 0.2 to 100 ng mL^-1, and the precision of the method (intra and inter-day assay) is <9.5%. The recoveries of real sample analysis were in the range of 89-101%. The method was successfully applied to the analysis of various real water samples and an alloy sample.