Solid-phase extraction and spectrophotometric determination of Allura Red (E129) in foodstuff, soft drink, syrup and energy drink samples: a comparison study

Amberlite XAD-7 and XAD-8 resins were used as adsorbents for preconcentration and determination of Allura Red (AR) food dye in aqueous medium. The effects of pH, sample volume, sample and eluent flow rates on the extraction of AR were optimised. The determination of dye was performed at 506.0 nm using spectrophotometry. Interference effects of matrix ions and some dyes were also investigated under optimised conditions. The methods permitted low detection limits which were 1.2 and 0.6 µg L-1 for XAD-7 and XAD-8, respectively. Adsorption behaviours were investigated by adsorption isotherms and zero charge pH experiments. Validations of the method were performed by determination of AR contents in some foodstuffs. AR contents of liquid samples were found between 58 and 440 µg mL-1. AR concentrations of solid samples were between 416 and 432 µg g-1. The XAD-7 and XAD-8 resins presented a fast and reliable potential to determine AR dye in real samples. © 2016 Institute of Food Science and Technolog

Studies on the heavy metal removal efficiency and antibacterial activity of 2-(diphenylphosphino)aminopyridine

The solvent extraction of metal picrates such as Ni2+, Cu2+, Co2+, Pb2+ and Cd2+ from the aqueous to the organic phase was studied using 2-(diphenylphosphino)aminopyridine (Ph2PNHpy). The effects of parameters including the pH of the aqueous phase and the ligand solution volume were investigated to de-termine the extraction ability of the ligand for metal ions. The results showed that the extraction percent-ages of metal ions were high at low pH values. The antibacterial activity of the aminophosphine was also screened against Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmuri-um (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. From the studies of antibacterial activity, it was observed that the ligand exhibited a potent inhibitory effect against all Gram-negative and Gram-positive bacteria with a diameter of inhibition zone ranging from 3.86 to 18.10 mm. The aminophosphine ligand (Ph2PNHpy) should be considered as a suitable bio-active molecule for anti-microbial material design and next-generation, non-toxic drug fabrication. The Ph2PNHpy obtained may have the potential for use as an antimicrobial additive for bioengineering applications. © 2018 özlem Sariöz, Burcu Malgaç, Yavuz Sürme, Sedef Ilk, Muhsin Karaarslan.Acknowledgements. This study was supported financially by the Research Projects Unit of Nigde Ömer Halisdemir University with project no FEB 2012/07. The authors would like to thank Dr Vefa Muradoğlu. The authors declare no conflict of interest

Electrochemical decolorization of CI Acid Orange 3 in the presence of sodium chloride at iridium oxide electrode

The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect electrochemical oxidation using an IrOx electrode was investigated. The effects of different operating parameters on the rate of dye decolorization were studied. The influences of mixing, electrolyte concentration, applied current, and initial dye concentration were examined. The change in dye concentration was followed by ultraviolet-visible spectroscopy, while the formation of reaction intermediates was established using high-performance liquid chromatography-mass spectrometry analysis. Ultraviolet-visible spectroscopy showed a decrease of the absorption peak at 374 nm during the electrolysis and the appearance of a new absorption maximum at 460 nm. The decolorization reaction can be followed only at 460 nm. Four intermediate products (two mono- and two dichlorinated) were detected. At the end of the study, a phytotoxicity assay was performed to determine the effectiveness of the applied method. The results showed that the applied electrochemical treatment of C.I. Acid Orange 3 leads to a decrease in phytotoxicity from 53 to 28%