Amino group functionalized metal-organic framework as dispersive solid-phase extraction sorbent to determine nitrobenzene compounds in water samples

Abstract To increase sensitivity and accuracy of the method for determination of nitrobenzene compounds, a metal organic framework, functionalized with amino groups, was employed as the sorbent for dispersive solid phase extraction to pretreat eight nitrobenzene compounds from environmental water samples. Grounded on the synergistic effects of hydrogen bonding (formed by nitro groups of nitrobenzene compounds and amino groups of the metal organic framework) and the tendency interaction (between nitro groups of nitrobenzene compounds and Zr containing moiety in the metal organic framework scaffold), the adsorption capacity and the kinetics were highly improved. By combining dispersive solid phase extraction with high-performance liquid chromatography, a sensitive and accurate method for simultaneous determination of eight major nitrobenzene compounds, including o ‑dinitrobenzene, o ‑Nitrochlorobenzene, p ‑Nitrochlorobenzene, p ‑Nitrotoluene, m ‑Nitrophenol, o ‑nitrophenol, p ‑nitroaniline and p ‑Nitrophenol was developed. Favorable linearity was achieved in the range of 10–300 μg L −1 with satisfactory coefficients ( r  ≥ 0.9992). The LODs (S/N = 3) and LOQs ( S  /  N  = 10) for 8 NBs ranged from 0.72 to 1.90 and from 2.33 to 5.71 μg L −1 , respectively. Satisfactory recovery of 85.2% to 104.5% were achieved for the tested samples. The proposed pretreatment method is expected to be widely applied to extract of NBs from water samples.