Confined silica particles in dually directional 1,2,3-triazolyl phthalonitrile based network: A robust nitrogen-rich Sorbent for the enrichment of nitroaromatics from water using HPLC-UV.

Owing to their extreme energetic properties, nitroaromatics (NACs) are well-recognized as explosive materials as well as toxic contaminations and source of environmental pollution. Thus, the development of accurate and extremely sensitive technologies for detecting NACs is critically necessary. In this study, the synthesis of a nitrogen-rich cross-linked polymer confining silica particles within its network structure (TPN-SiO2) is being described. The TPN-SiO2 material was successfully prepared, in situ, via the Cu(I)-mediated azide-alkyne cycloaddition (CuAAC) polymerization of dually directional alkyne-terminated phthalonitrile monomers with 1,4-bis(azidomethyl)benzenes in the presence of silica particles. The resulting encapsulated silica network was fully characterized using its respective XPS, SEM, TEM, and FT-IR spectroscopic data, along with TGA analysis. TPN-SiO2 was applied as an effective sorbent in solid phase extraction (SPE) for the enrichment of nitrobenzene compounds (NBs) before quantification by HPLC-UV. Three NBs (nitrobenzene, 4-nitrotoluene, and 2-nitrobenzaldehyde) were used to evaluate the effectiveness of the prepared SPE sorbent. Accordingly, and under optimal analytical extraction conditions, the results revealed a good linearity from 0.1-50 μgmL-1 with correlation coefficients (R2) higher than 0.990. As well to this, the limits of detection and quantification were determined to be 2.4-33.9 μgL-1 and 7.17-102.88 μgL-1, respectively, making this hybrid silica triazolyl-rich cross-linked sorbent appropriate for NBs enrichment and detection.