Preparation of Ti3C2Tx MXene based solid-phase microextraction coating for sensitive determination of polychlorinated biphenyls in environmental water samples

In this study, a new Ti3C2Tx-coated fiber was synthesized and utilized as coatings for solid-phase microextraction of seven polychlorinated biphenyls. The as-produced multilayered Ti3C2Tx MXene was characterized by X-ray diffractometer, thermos-gravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. It is noteworthy that the Ti3C2Tx showed some attractive features including unique 2D layered structures, large surface area, good hydrophilicity, and rich active recognition sites, endowing it has a high affinity towards the target polychlorinated biphenyls. Subsequently, the affecting parameters on the extraction efficiency of polychlorinated biphenyls were optimized. Under the optimal conditions, a novel method for the analysis of polychlorinated biphenyls in water samples was proposed. The Ti3C2Tx-coated fiber-based solid-phase microextraction method showed good linearity (r(2) > 0.9928), high enrichment factors (268-442), low limits of detection (0.06-0.15 ng/L), and satisfactory repeatability (RSDs < 7.5%) for the polychlorinated biphenyls. The excellent method recoveries were in the range of 90.0-98.4, 92.0-98.2, and 92.0-98.0% for river water, lake water, and tap water samples, respectively. These results suggested that the proposed Ti3C2Tx-coated fiber-based method represents a promising alternative for the analysis of polychlorinated biphenyls.