Atmospheric pressure plasma-assisted epichlorohydrin-grafting onto pineapple fiber and immobilization with polyethyleneimine for -nitrophenol removal.

The cost-effective, eco-friendly, and easily available adsorbent prepared using atmospheric pressure plasma (APP)-induced epichlorohydrin-grafting onto alkali-treated pineapple leaf fiber (APF) and immobilization with polyethyleneimine (PEI) was investigated and applied for -nitrophenol (PNP) removal. The results from main characterization methods such as morphological observation, Fourier transform infrared analysis, and x-ray photoelectron spectroscopy revealed the surface changes and confirmed the success of the surface modifications. According to the experimental data, APP pre-treated adsorbent following by PEI immobilization (t-APF--PEI) exhibited fast and efficient adsorption with the adsorption capacity up to 128 mg/g, whereas the adsorption capacities for APF--PEI and APF were 115 and 21 mg/g, respectively, at 30 °C.

Fabrication of montmorillonite composite alginate beads for micro-solid phase extraction of carbamate residues prior to their determination by ultra performance liquid chromatography-photodiode array detector.

This paper reports the employment of natural montmorillonite (Cloisite Na) and sodium alginate (Alg) to fabricate sorbent beads and applied for extraction and preconcentration of carbamates (CBMs) based on micro-solid phase extraction (μ-SPE) method prior to analysis by ultraperformance liquid chromatography coupled with a photodiode array detector (UPLC-PDA). Cloisite Na/Alg composite bead was synthesized by ionic gelation method using calcium chloride as a cross-linking agent at ambient temperature. The biocomposite sorbent bead was then characterized by various techniques, including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA).