Ion chromatography for monitoring [NTf2]- anion contaminants in pure and saline water

Preparation and chromatographic evaluation of a mixed polymer brush-silica stationary phase with temperature-sensitive property

In this study, a developed chromatographic stationary phase combines the high selectivity of mixed-mode retention with a temperature-responsive property to boost separation efficiency. Copolymer brushes were grafted onto silica gels through surface initiated-atom transfer radical polymerization by polymerizing two types of monomer, temperature-responsive vinylcaprolactam (VCl) and quinine (Qun) containing benzopyridine, a tertiary ammonium positive center, and hydroxyl groups. The obtained silica@poly(Qun-co-VCl) stationary phases were packed as a chromatographic column, and the retention behavior of hydrophobic polycyclic aromatics, highly polar nucleosides, charged organic acids and β-agonists was studied for this column under different separation modes. The ability to separate different types of analyte shows that the silica@poly(Qun-co-VCl) column provides multiple hydrophobic, hydrophilic and electrostatic interactions toward analytes, achieving the separation of various compounds in one column. In addition, temperature-dependent resolution of polycyclic aromatics, nucleosides, organic acids and β-agonists was investigated using modulation of the column temperature, and the column exhibited adjustable separation selectivity by simply changing the column temperature. These results demonstrate that the grafting of copolymer brushes on a silica surface, consisting of temperature-responsive poly-VCl and multifunctional groups of poly-Qun, is useful as a mixed-mode chromatographic stationary phase for thermally-modulated multiple interactions. Additionally, this column was also used for the quantitative detection of uridine and inosine from cordyceps.

Application of a phosphonium-based ionic liquid for reactive textile dye removal: Extraction study and toxicological evaluation

Textile dyeing processes are known for their negative environmental impacts due to the production of aqueous effluents containing toxic dyes. Therefore, new wastewater treatment processes need to be developed to treat such effluents, including Liquid-Liquid Extraction (LLE) process using Ionic Liquids (IL). This work aimed to evaluate the application of the hydrophobic IL trihexyltetradecylphosphonium decanoate to extract black, navy, and royal reactive dyes from water and evaluate the toxicological aspects of the resulting water stream. We investigated the effect of selected parameters, such as pH (2-12), temperature (20-50 °C), salt effects, dye concentration (0.5-50 mg/L), and phase volume ratio (900-9000) on the dye extraction. The results showed extraction yields as high as 97% for the three dyes and an extraction capacity of approximately 300 mg/g for black and navy dyes and 400 mg/g for royal. The toxicity tests involved Lactuca sativa, Triticum aestivium L, and Daphnia magna as bioindicators. The difference between the toxicity of the dye solutions before and after extraction was not statistically significant when L. sativa and Triticum aestivum L were used as bioindicators. However, the extracted solution showed increased toxicity towards D. magna due to traces of IL. Overall, the IL has a high extraction capacity for the black, navy, and royal dyes. Nevertheless, further studies on LLE associated with other processes must be carried out to reduce the risk linked to the toxicity of IL transferred to the water.