Carbonyl compounds responsive 2,4-dinitrophenylhydrazine doped polydimethylsiloxane based membrane as alternative derivatizing strategy prior to in-tube solid phase microextraction coupled with capillary liquid chromatography analysis.

In this work, a DNPH doped PDMS based membrane was developed to facilitate carbonyl compound derivatization. This membrane delivers DNPH in presence of carbonyl compounds to form hydrazones. Subsequently, the resulting hydrazones are preconcentrated, separated and detected by in-tube solid phase microextraction (IT-SPME) coupled on-line with capillary liquid chromatography (CapLC) with Uv-Vis diode array detection (DAD).

Assessing the size transformation of nanoplastics in natural water matrices.

Understanding the stability of NPs in different aqueous environments, related with their size is crucial for assessing their potential risks. This is influenced by several factors, including pH, ionic strength, and the presence of biomolecules, or dissolved organic matter (DOM). In this study, dispersions of NPs derived from common plastic waste materials, including polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), and polycarbonate (PC), were synthesized by a nanoprecipitation method with sizes: 189 ± 7, 58 ± 3, 123 ± 4, 151 ± 7 and 182 ± 6 nm, respectively.

Miniaturized liquid chromatography in environmental analysis. A review.

The greater and more widespread use of chemicals, either from industry or daily use, is leading to an increase in the discharge of these substances into the environment. Some of these are known to be hazardous to humans and the environment and are regulated, but there is a large and increasing number of substances which pose a potential risk even at low concentration and are not controlled. In this context, new techniques and methodologies are being developed to deal with this concern.

Towards a zero liquid discharge process from brine treatment: Water recovery, nitrate electrochemical elimination and potential valorization of hydrogen and salts.

This research addresses the issues related with treatment and valorization of brines and nitrate decontamination of surface and ground waters. The objective was to approximate to zero liquid discharge (ZLD) minimizing the environmental impact of brines of an electrodialysis reversal water treatment plant (EDRWTP) as an example. The innovative in flow process was developed from lab to pre-industrial scale and joined several main concepts: ion-exchange equilibrium for softening or demineralization of brines; reversed osmosis to recover suitable water and to enrich the waste in nitrate for efficient electrochemical reduction of NO to N; valorization of subproducts by direct use or by precipitation; and assessment of the whole process by measuring in-line several parameters.

Colorimetric analysis platform based on thin layer chromatography for monitoring gluten cross-contamination in food industry.

Monitoring of the accidental presence of gluten (Glu), resulting from cross-contamination, is imperative in different industries, in particular food industry. The objective of this study was the development of an analytical platform utilizing thin-layer chromatography (TLC) with colorimetric read-out for making binary (yes/no) decisions on surfaces and/or point of these industries. The composition of the extractive phase was optimized with commercial products used in cleaning processing lines.