Carbon Fiber Modified with Santa Barbara Amorphous-15 for In-Syringe Solid-Phase Extraction of Benzene Derivatives

A method of in-syringe solid-phase extraction (SPE) using carbon fiber modified with Santa Barbara amorphous-15 (CF-SBA-15) as an adsorbent, coupled with gas chromatography-mass spectrometry, was developed for the determination of benzene derivatives in seawater samples. Carbon fiber was modified with amine-functionalized SBA-15 to prepare CF-SBA-15 through covalent functionalization. Fabricated CF-SBA-15 was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, confirming the successful modification of CF with SBA-15 and its ordered hexagonal mesoporous structure. As a novel in-syringe SPE adsorbent, it was used for the determination of 12 benzene derivatives by gas chromatography-mass spectrometry. Benzene derivatives could be completely adsorbed on CF-SBA-15 during one adsorption cycle, indicating effective extraction with a short time. Under the optimized extraction and elution conditions, the linear ranges were 0.1–500 ng/mL with regression coefficients above 0.9960, the limits of detection were 0.008–0.25 ng/mL, and intra- and inter-day relative standard deviation values were below 12.8% in standard and seawater samples. The enrichment factor (EF), recovery (R), and matrix effect (ME) were investigated, indicating that CF-SBA-15 is selective and quantitative for the extraction of all analytes (EF: 17.1–19.4, R: 85.6–96.8%, and ME: 86.0–110.5%). The proposed method was applied to the determination of benzene derivatives in seawater samples.