Multiple-helix cobalt(II)-based metal-organic nanotubes on stainless steel fibers for solid-phase microextraction of chlorophenol and nitrophenols from water samples

The high performance solid-phase microextraction (SPME) of polar phenols from aqueous matrices is a challenge due to the strong interaction between water molecules and polar phenols. The authors describe the fabrication of stainless steel fibers coated with multiple helix 3D metal-organic nanotubes via physical adhesion, and their application to the SPME of 2-chlorophenol, 2-nitrophenol, 2,4-dichlorophenol, 4-chloro-3-methylphenol and 2,4,6-trichlorophenol from water samples. GC/MS was used for sample quantification and detection. Box-Behnken design was adopted to optimize the experimental conditions through response surface methodology. The fibers display good thermal stability (~400 °C), high enrichment factors (418–1874), excellent repeatability (4.31%–8.37%), wide linear range (0.5–1000 ng⋅L −1 ) and low limits of detection (0.07–0.18 ng⋅L −1 ) for the phenols. This method was successfully applied to the analysis of phenols in environmental water samples. Multiple helix 3D metal-organic nanotubes coated stainless steel fibers were fabricated. The fibers achieved good thermal stability (~400 °C), high enrichment factors (418–1874), excellent repeatability (4.31–8.37%), wide linear range (0.5–1000 ng L −1 ) and low limits of detection (0.07–0.18 ng L −1 ) for phenols.