Carbonized Aramid Fiber as the Adsorbent for In-Tube Solid-Phase Microextraction to Detect Estrogens in Water Samples

Carbonized aramid fiber was prepared as a new type of adsorbent for in-tube solid-phase microextraction. The surface structure, chemical composition, and graphitization degree of the resulted fiber was determined and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectrometry. The prepared fiber was packed in a stainless-steel tube instead of the sample loop of a six-port and tested for the extraction of five environmental estrogen hormones coupled with high-performance liquid chromatography. Several parameters affecting the estrogens’ extraction including the sampling volume, sampling rate, NaCl content, and desorption time were investigated in detail. The extraction tube with carbonized aramid fiber exhibited remarkable extraction performance towards five estrogen targets. The analysis method was established, and it exhibited a wide linear range (0.5–10.0 μg/L) with good linearity (correlation coefficient ≥0.9906), low limits of detection (0.011–0.13 μg/L), and high enrichment factors (178–1335) for the five analytes. Relative standard deviations (n = 3) for intraday (≤4.8%) and interday (≤4.0%) tests indicated that the extraction material had satisfactory repeatability. Bisphenol A released from a polycarbonate (PC) bottle was quantitatively detected with a concentration of 8.3 μg/L. The relative recoveries spiked at 5 and 10 μg/L were investigated, and the results were in the range of 74.3–121% for real water samples.

Electroless deposition of silver nanofractals on copper wire by galvanic displacement as a simple technique for preparation of porous solid-phase microextraction fibers

A novel and porous solid-phase microextraction fiber was prepared by quick and simple galvanic displacement reaction and applied to the determination of some polycyclic aromatic hydrocarbons in sunflower oil. The parameters affecting the porosity and thickness of the fiber, and parameters affecting the extraction efficiency, including the extraction time, temperature, and ionic strength, were investigated and optimized. The morphology of prepared fiber was characterized by optical and scanning electron microscopy and thermal and chemical stabilities of the fiber were studied. Under the optimum conditions, the limits of detection ranged between 0.1 ng/mL for pyrene to 1.2 ng/mL for anthracene, and LOQ ranged between 0.3 ng/mL for pyrene to 3.6 ng/mL for anthracene. The relative standard deviations, including repeatability (within fibers) and reproducibility (between fibers), varied between 3.2-8.9 and 5.6-9.8%, respectively.