Seminar Series

Students Abroad Seminars

Speaker

Maria Plunkett, University of Sheffield: Quinoxaline Based Ligands: Synthesis and Complexation Andrew Kannan, University of Bath: Investigating the Efficiency of Nylon and Polyethylene as Sorbents for Sample Extraction of Selected Emerging Contaminants

Institute

Time & Place

Wed, 01 Jun 2016 12:00:00 NZST in Rutherford Room 531

All are welcome

Abstract

Quinoxaline Based Ligands: Synthesis and Complexation

Polydentate ligands incorporating two or more discrete binding sites for metal ions possess a wide range of applications, from creating large supramolecular architectures to facilitating photoinduced ligand release. Careful design and an understanding of possible coordination modes of individual components is key to the synthesis of such molecules, and it is this understanding that is explored alongside the synthesis of new quinoxaline based polydentate ligands.

Investigating the efficiency of Nylon and Polyethylene as sorbents for sample extraction of selected emerging contaminants

This study explored method development for sample extraction of selected emerging contaminants using Nylon and Polyethylene sorbents. A range of emerging contaminants were examined which varied in their chemical properties and tendency to adsorb to plastics. These compounds included; Bisphenol A, Benzophenone-3, 17α-Ethinylestradiol, 4-Octylphenol and Triclosan.

The method of sample extraction was modified to obtain the greatest sorption onto the sorbents and hence the greatest recovery from the plastics. The factors investigated for their effect on recovery included the types of plastic, single vs mix spikes of emerging contaminants and the salt concentrations of the samples. HPLC-UV was used for the detection and measurement of the compounds after recovery. Nylon recovered all model compounds. The percentage recoveries were; Bisphenol A (49%), 4-Octylphenol (20%), 17α-Ethinylestradiol (63%), Benzophenone-3 (19%), Triclosan (89%). Polyethylene was not able extract bisphenol A and gave significantly lower compound recovery percentages; 4-Octylphenol (4%), 17α- Ethinylestradiol (0.5%), Benzophenone-3 (9%) and Triclosan (8%). For the nylon sorbent, high NaCl concentrations increased recoveries for bisphenol A, 17α-ethinylestradiol and benzophenone-3 and decreased recovery for triclosan. For the polyethylene sorbent, increased NaCl concentration only improved recovery for 17α-ethinylestradiol increasing its recovery to 3.3%.

Recommendations for future work include determining the optimal pH for each individual compound, testing environmentally relevant concentrations of contaminants (ultra-trace levels) and measuring the rate of sorption to see if the extraction time can be lowered.