Preconcentration of allergenic disperse dyes in environmental water samples based on amino functionalized metal–organic framework

Abstract

An amino functionalized metal organic framework was synthesized by hydrothermal synthesis method. The hydrophilic organic ligand and chromium (III) provide respectively lone pair electron and unoccupied orbital, which promoted the construction of spatial topological structure. The surface morphology and textural properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption- desorption. The amino-adsorbent were applied to the analysis of five allergenic disperse dyes (disperse blue 35a, disperse red 1, disperse blue 106, disperse orange 37. disperse brown 1) by dispersive solid phase extraction in environmental water samples coupled with ultra high performance liquid chromatography-tandem mass spectrometry. The important influence parameters on the extraction efficiency of target analytes were investigated through univariate and orthogonal experiment, including adsorbents amount, pH, NaCl concentration, desorption conditions and extraction time. The experimental results indicated that the relative recoveries of allergenic disperse dyes were over 85.0% with 8.0 mg adsorbents within 6.5 min. The average recoveries of five target analytes were increased 22.9% compared with non-functionalized adsorbents (75.7%). The limits of detection (LODs) and limits of quantification (LOQs) were in a range of 0.36–16.9 ng/L and 1.2–56.5 ng/L, respectively. The developed method was successfully applied to the determination of disperse dyes in actual water samples, the relative recoveries were in the range from 87.6 to 108.9% and the relative standard deviations varied between 2.1 and 7.8%. The results indicated that the proposed method was effective and practicable for the analysis of the trace organic pollutants from actual environmental water media.