title: Metal-organic-framework-based tandem molecular sieves as a dual platform for selective microextraction and high-resolution gas chromatographic separation of n-alkanes in complex matrixes.
abstract: Metal-organic frameworks (MOFs) were employed to design tandem molecular sieves as a dual platform for selective solid-phase microextraction (SPME) and high-resolution gas chromatographic (GC) separation of target analytes in complex matrixes. An elegant combination of a ZIF-8-coated fiber for SPME with a ZIF-8-coated capillary for GC allows selective extraction and separation of n-alkanes from complex matrixes such as petroleum-based fuel and biological fluids. The proposed tandem ZIF-8 molecular sieves not only offered good enhancement factors from 235 (hexane) to 1212 (nonane), but also exhibited wide linearity with 3 orders of magnitude for the tested linear alkanes. The limits of detection for the linear alkanes ranged from 0.46 ng L(-1) (nonane) to 1.06 ng L(-1)(hexane). The relative standard deviations of retention time, peak area, peak height, and half peak width for five replicate determinations of the tested n-alkanes at 30 ng L(-1) were 0.02-0.26%, 1.9-8.6%, 1.4-6.0%, and 1.3-7.2%, respectively. The developed tandem ZIF-8 molecular sieves were further used for the determination of linear alkanes in petroleum-based fuel and human serum. The large diversity in structure and pore size allows various combinations of MOFs for designing an MOF-based tandem molecular sieve platform to achieve different selectivities in extraction and chromatographic separation and to solve headache problems in complex real sample analysis.
authors.affiliation: Research Center for Analytical Sciences, College of Chemistry, and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Na
authors.initials: N
authors.lastname: Chang
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Gu
authors.forename: He-Fang
authors.initials: HF
authors.lastname: Wang
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan
mesh_terms: D000473:Alkanes / Q000737:chemistry / Q000302:isolation & purification*; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D006586:Hexanes / Q000737:chemistry / Q000302:isolation & purification; D008670:Metals / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry*; D010578:Petroleum / Q000032:analysis; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D000473:Alkanes; D006586:Hexanes; D008670:Metals; D009930:Organic Chemicals; D010578:Petroleum; C017573:nonane