title: Development of solid-phase microextraction fibers based on multi-walled carbon nanotubes for pre-concentration and analysis of alkanes in human breath.
abstract: In this work, a laboratory preparation method based on sol-gel technology was proposed to develop a new kind of SPME (solid phase microextraction) fibers. Multi-walled carbon nanotubes (MWCNT) were selected as sol-gel active organic component. Stainless steel wires were used as the substrate of the fibers. Instead of traditional modification methods, microwave induced plasma was used to modify the stainless steel wire surface, resulting in a significant improvement in chemical adhesion of the fiber substrate and coating. The MWCNT coating exhibited several good properties. Acceptable fiber-to-fiber reproducibility (RSD≤13%) and repeatability (RSD<7%) were obtained. End-tidal breath of 10 normal humans were collected by Bio-VOC(®) sampler and assayed by the optimized SPME-GC-MS method. The calibration curves were all linear (R(2)≥0.994) in the range from 0.03 to 403.3ppbv for five alkanes. Detection limits (down to 0.001ppbv) were about one order of magnitude better than those of commercial PDMS fibers. The recovery of the spiked alkanes in real breath sample at 1ppbv ranged from 89.71 to 101.08% and the relative standard deviations were less than 8%. These results demonstrated the feasibility and practicality of the proposed preparation procedure. Applications of the in-house fabricated fibers for human breath analysis were successfully verified.
authors.affiliation: Research Center of Analytical Instrumentation, Analytical & Testing Center, Sichuan University, Chengdu, China.
authors.forename: Zhentao
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Research Center of Analytical Instrumentation, Analytical & Testing Center, Sichuan University, Chengdu, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China. Electronic address: yduan@scu.edu.cn.
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Duan
mesh_terms: D000473:Alkanes / Q000032:analysis*; D001944:Breath Tests; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D057230:Limit of Detection; D037742:Nanotubes, Carbon; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D013193:Stainless Steel
chemical_list: D000473:Alkanes; D037742:Nanotubes, Carbon; D013193:Stainless Steel
keywords: Alkanes; Human breath; Microwave induced plasma; Multi-walled carbon nanotubes; SPME; Sol–gel technology