Metal-organic framework-based magnetic dispersive micro-solid-phase extraction for the gas chromatography-mass spectrometry determination of polycyclic aromatic compounds in water samples.

A magnetic hybrid material based on the use of the mixed-ligand Metal-Organic Framework (MOF) PUM198 is proposed for the magnetic dispersive micro solid-phase extraction (MD-µSPE) of the 16 polycyclic aromatic hydrocarbons (PAHs) included in the US-EPA priority pollutants list. PUM198 is a thermally robust MOF characterized by a doubly interpenetrated microporous framework in which Zn2+ ions and carboxylate groups define 2D planes that are pillared by a bis-pyridine-bis amide ligand containing a biphenyl scaffold. PUM198 revealed to be ideal to adsorb PAHs efficiently through non-covalent interactions. A Plackett-Burman Design followed by a Central Composite Design and the multicriteria method of the desirability functions were applied to find the optimal conditions for the extraction of the investigated PAHs, resulting in a reduced solvent consumption, i.e., 50 µL of solvent per extraction for 5 mL of sample, approximatively 3-20 times lower than those reported in previous studies, thus satisfying the principles of green analytical chemistry. Method validation proved the reliability of the method for the determination of PAHs at trace level, obtaining detection limits in the 6.7-27 ng/L range, good precision with RSDs% lower than 19% and recovery rates in the 99 (±13)-126 (±8)% range near the quantitation limit. Finally, the applicability of the method was demonstrated by analyzing underground water samples taken from contaminated sites.

Synthesis, characterization, antimicrobial and cytotoxic activity and DNA-binding properties of d-metal complexes with hydrazones of Girard's T and P reagents.

In this work synthesis, characterization and crystal structures of 1, Zn(II) complex ([ZnL1(NCS)2]), with (E)-1-(2-oxo-2-(2-(quinolin-2-ylmethylene)hydrazinyl)ethyl)pyridin-1-ium chloride (HL1Cl) and 2, Bi(III) complex ([BiHL2Cl4] × 1/2CH3OH), with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL2Cl), have been reported. Zn(II) complex possesses a distorted trigonal bipyramidal geometry while surroundings around Bi(III) ion are extended pentagonal bipyramidal. Antimicrobial activity, brine shrimp assay and DPPH radical scavenging activity of both complexes, including previously synthesized complexes with HL2Cl ligand (Zn(II) and Ni(II)) and complexes with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL3Cl) (Zn(II), Cu(II), Cd(II), Co(II), Fe(III), Ni(II)), were evaluated. For the most active complexes, cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and normal cell line HaCaT, as well as generation of reactive oxygen species (ROS), was tested.

Development of novel cocrystal-based active food packaging by a Quality by Design approach.

A way to reduce food waste is related to the increase of the shelf-life of food as a result of improving the package type. An innovative active food packaging material based on cocrystallization of microbiologically active compounds present in essential oils i.e. carvacrol, thymol and cinnamaldehyde was developed following the Quality by Design principles. The selected active components were used to produce antimicrobial plastic films with solidified active ingredients on their surface characterized by antimicrobial properties against four bacterial strains involved in fruit and vegetable spoilage. The developed packaging prototypes exhibited good antimicrobial activity in vitro providing inhibition percentage of 69 (±15)% by contact and inhibition diameters of 32 (±6) mm in the gas phase, along with a prolonged release of the active components. Finally, the prolonged shelf-life of grape samples up to 7 days at room temperature was demonstrated.