(2017) Microchemical Journal_Metal-organic frameworks as superior media for thermal desorption-gas chromatography application: A critical assessment of MOF-5 for the quantitation of airborne formaldehyde

Kim Y.-H., Kumar P., Kwon E.E., Kim K.-H.

(Elsevier Inc.) Microchemical Journal ISSN: 0026265X Vol.132 Issue. Article No. DOI: 10.1016/j.microc.2017.01.032

In this study, formaldehyde (FA) in the air was collected and analyzed using metal-organic framework-5 (MOF-5) as the sorbent material (for both sorbent tube (ST) sampling and thermal desorption (TD) analysis) in gas chromatography-mass spectrometry (GC-MS) detection. A series of experiments was carried out to determine the optimal analytical conditions for maximum recovery of FA by TD-GC-MS. Optimal TD conditions for adsorption and desorption of MOF-5 were determined to be − 25 °C and 100 °C, respectively. These conditions yielded good linearity (R² = 0.9975), precision (mean 1.79 ± 1.17%), and high sensitivity. The method detection limit (MDL) of 0.1 ng was attained to determine 0.82 ppb of FA in 100 mL of air (limit of detection (LOD) of 8 pg (0.06 ppb)). The concentration of FA, when measured from ambient air samples using MOF-5, averaged 9.67 ppb (n = 3, RSE = 2.39%). FA samples, when analyzed in parallel using the DNPH cartridge-HPLC-UV system recommended by the US EPA, yielded similar results (mean of 10.5 ppb) to the MOF-5 dataset. In addition, trace quantities of FA (0.25 ng) were also detected from samples of as little as 20 mL of air. Our results suggest that MOF-5 is a suitable sorbent media for thermal desorption analysis and in fact surpasses the performance of commercial sorbents used for VOC analysis. As such, a GC-based detection method for FA comprising simple thermal desorption without complicated procedures, such as a derivatization step, was realized. © 2017 Elsevier B.V.

This research was supported by a grant (14182MFDS977) from the Ministry of Food and Drug Safety in 2016. This study was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (No. 2016R1E1A1A01940995). This research was also supported partially by the R&D Center for Green Patrol Technologies through the R&D for Global Top Environmental Technologies funded by the Ministry of Environment (MOE), Republic of Korea.