A promising sensing platform for explosive markers: Zeolite-like metal-organic framework based monolithic composite as a case study

Kareem Yusuf; Osama Shekhah; Seetah Alharbi; Asma A Alothman; Ali S Alghamdi; Reem M Aljohani; Zeid A ALOthman; Mohamed Eddaoudi

doi:10.1016/j.chroma.2023.464326

A promising sensing platform for explosive markers: Zeolite-like metal-organic framework based monolithic composite as a case study

J Chromatogr A. 2023 Sep 27:1707:464326. doi: 10.1016/j.chroma.2023.464326. Epub 2023 Aug 24.

Authors

Kareem Yusuf¹, Osama Shekhah², Seetah Alharbi³, Asma A Alothman³, Ali S Alghamdi³, Reem M Aljohani⁴, Zeid A ALOthman⁴, Mohamed Eddaoudi²

Affiliations

¹ Advanced Materials Research Chair (AMRC), Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia. Electronic address: kmahmoud@ksu.edu.sa.
² Functional Materials Design, Discovery and Development Research Group (FMD3), Advanced Membranes and Porous Materials Centre (AMPMC), Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), PO Box 6900, Jeddah 23955, Saudi Arabia.
³ Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia.
⁴ Advanced Materials Research Chair (AMRC), Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia.

PMID: 37639846
DOI: 10.1016/j.chroma.2023.464326

Abstract

Preconcentration for on-site detection or subsequent determination is a promising technique for selective sensing explosive markers at low concentrations. Here, we report divinylbenzene monolithic polymer in its blank form (neat-DVB) and as a composite incorporated with sodalite topology zeolite-like metal-organic frameworks (3-ZMOF@DVB), as a sensitive, selective, and cost-effective porous preconcentrator for aliphatic nitroalkanes in the vapor phase as explosive markers at infinite dilution. The developed materials were fabricated as 18 cm gas chromatography (GC) monolithic capillary columns to study their separation performance of nitroalkane mixture and the subsequent physicochemical study of adsorption using the inverse gas chromatography (IGC) technique. A strong preconcentration effect was indicated by a specific retention volume adsorption/desorption ratio equal to 3 for nitromethane on the neat-DVB monolith host-guest interaction, and a 14% higher ratio was observed using the 3-ZMOF@DVB monolithic composite despite the low percentage of 0.7 wt.% of sod-ZMOF added. Furthermore, Incorporating ZMOF resulted in a higher percentage of micropores, increasing the degree of freedom more than bringing stronger adsorption and entropic-driven interaction more than enthalpic. The specific free energy of adsorption (ΔG^S) values increased for polar probes and nitroalkanes, denoting that adding ZMOFs earned the DVB monolithic matrix a more specific character. Afterward, Lewis acid-base properties were calculated, estimating the electron acceptor (K_A) and electron donor (K_B) constants. The neat-DVB was found to have a Lewis basic character with K_B/K_A = 7.71, and the 3-ZMOF@DVB had a less Lewis basic character with K_B/K_A = 3.82. An increased electron-accepting nature can be directly related to incorporating sod-ZMOF into the DVB monolithic matrix. This work considers the initial step in presenting a portable explosives detector or preconcentrating explosive markers trace prior to more sophisticated analysis. Additionally, the IGC technique allows for understanding the factors that led to the superior adsorption of nitroalkanes for the developed materials.

Keywords: Adsorption; Explosive markers; Gas chromatography; Metal-organic frameworks; Preconcentration.

MeSH terms

Alkanes
Explosive Agents*
Lewis Bases
Metal-Organic Frameworks*
Polymers
Zeolites*

Substances

Metal-Organic Frameworks
Explosive Agents
Zeolites
Polymers
Alkanes
Lewis Bases