RESUMO
Metal-organic nanotubes (MONTs) have great potential for solid phase microextraction (SPME) on account of high specific surface area, tunable pore sizes, and exceptional thermal and chemical stability. In this work, zinc (II)-based metal-organic nanotubes (Zn-MONTs) were used as an adsorbent for the SPME of nitro-polycyclic aromatic hydrocarbons (NPAHs) at trace levels from environmental water samples. Gas chromatography-mass spectrometry was used for sample analysis and key factors were investigated and optimized. Under optimal parameters, the developed method achieved low limits of detection (1.4-7.3â¯ngâ¯L-1), wide linear range (10-5000â¯ngâ¯L-1), and high enrichment factors (1510-17,684). In comparison to the PDMS and DVB/CAR/PDMS fiber for potential commercial use, the Zn-MONTs fiber obtained MS responses 2-9 times as high as those achieved by the commercial 100⯵m PDMS and 0.2-2.3 times higher than 50/30⯵m DVB/CAR/PDMS fiber did. The proposed method was successfully used in the analysis of NPAHs at trace levels in environmental samples.
RESUMO
In this study, stable cadmium(II)-based metal-organic nanotubes (Cd-MONTs) were prepared and used as a coating material for solid-phase microextraction (SPME) of polychlorinated biphenyls (PCBs) from environmental water samples. The as-prepared Cd-MONT SPME coating material was characterized by thermal gravimetric analysis, scanning electron microscopy, and X-ray diffraction. The synthesized Cd-MONTs exhibited high thermal stability (385 °C) and excellent extraction performance toward PCBs. The important conditions were optimized systematically by the response surface method. Under the optimal conditions, the new fiber achieved high enrichment factors (938-3417), low limits of detection (1.80-8.73 pg L-1), and wide linearity (10-5000 pg L-1). The method developed was used in ultratrace-level analysis of PCBs in seawater samples, with satisfactory results for each sample.