Selective Determination of n-Hexane and Methyl Ethyl Ketone (MEK) in Urine by Magnetic-Silica Aerogel-Based Molecularly Imprinted Polymers (MIPs) with Gas Chromatography - Flame Ionization Detection (GC-FID)

• Published in: Analytical letters Vol. 56; no. 8; pp. 1292 - 1311
• Main Authors: Vahabi, Masoomeh, Ebrahimzadeh, Homeira, Zendehdel, Rezvan, Jalilian, Niloofar, Khodakarim, Soheila
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 24.05.2023; Taylor & Francis Ltd
• Subjects: Biomonitoring; Chromatography; Flame ionization; Fourier transforms; Gas chromatography; Gas chromatography - flame ionization detection (GC-FID; Hexanes; Imprinted polymers; Infrared analysis; Iron oxides; Magnetic measurement; magnetic-silica aerogel; Methyl ethyl ketone; methyl ethyl ketone (MEK; molecularly imprinted polymers (MIPs; n-hexane; neurotoxic chemicals; Risk management; Selectivity; Silica aerogels; Silicon; Solid phases; Thermogravimetric analysis; Urine; Vibration analysis
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1080/00032719.2022.2128364

Co-exposure to n-hexane and methyl ethyl ketone (MEK) may induce neurotoxicity in humans. Since biomonitoring of exposed chemicals is a powerful hygienic way of controlling chemical risk, a new molecularly imprinted polymer (MIP) is reported in this study. Polymerization was carried out upon the surface of magnetic silica aerogel (Si@Fe 3 O 4 ) using 2-octanone as a dummy template to prepare Si@Fe 3 O 4 -MIP. The synthesized MIP was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrometry thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) analysis, and vibration sample magnetometry (VSM). The reported method was utilized for the selective extraction of n-hexane and MEK from humane urine using gas chromatography - flame ionization detection (GC-FID). The highest selectivity coefficient of Si@Fe 3 O 4 -MIP was obtained for n-hexane and MEK. The validity of solid phase extraction (SPE)-based Si@Fe 3 O 4 -MIP was confirmed by the recovery (> 93.6%) and acceptable reproducibility was obtained with relative standard deviations between 1.6 and 8%. The limit of quantifications (LOQ) for n-hexane and MEK were 1.5 and 128 µg/L, respectively. The validated SPE-based Si@Fe 3 O 4 -MIP is suggested for determining n-hexane and MEK in urine of shoemaker workers for biomonitoring purposes.