Selective determination of metal chlorocomplexes in saline waters by magnetic ionic liquid-based dispersive liquid-liquid microextraction.

In this work, we explore a new dispersive liquid-liquid microextraction (DLLME) method to selectively separate chemical species of Cd and Zn in saline waters. It is based on the use of the magnetic ionic liquid (MIL) methyltrioctylammonium tetrachloroferrate ([N][FeCl]), which allows an efficient and environmentally friendly extraction of the target species. In addition, the paramagnetic component in the MIL simplifies the separation step required in DLLME, allowing for fast separation and recovery of the extracted species with a magnet, without a centrifugation step.

A liquid micro-extraction based one-step method for the chemical fractionation of copper in seawater.

In this work, the reagent Cyanex® 272 has been incorporated in a three-phase solvent bar micro-extraction system to selectively separate the inorganic and organic fractions of copper in seawater. Optimized conditions for micro-extraction of Cu fractions were 0.2 M Cyanex® 272 in the organic solution contained into the fiber pores, 0.

Selective ionic liquid solvent bar micro-extraction for estimation of ultra-trace silver fractions in marine waters.

Ag can be found in the ocean at the ultra-trace level, mainly as AgCl and complexed by dissolved organic matter (Ag-DOM). However, methods for studying Ag speciation in marine waters are limited by the lack of extractants capable to separate organic and inorganic silver species in natural conditions of seawater samples. In this work, a two-phase solvent bar micro-extraction method using the ionic liquid trihexyltetradecylphosphonium chloride (Cyphos® 101) was applied for selective micro-extraction of AgCl from organic silver in marine waters, working at seawater pH,.

Multi-elemental ionic liquid-based solvent bar micro-extraction of priority and emerging trace metallic pollutants (Cd, Ag, Pd) in natural waters.

Transition metals Cd, Pd and Ag are toxic even at very low concentration. Cd is considered a priority substance; while, Pd and Ag are emerging pollutants. Membrane technologies have been applied for their extraction; however, they require important amounts of reagents, time and energy.

Ionic liquid solvent bar micro-extraction of CdCl species for ultra-trace Cd determination in seawater.

Water analysis of trace metals has been benefited by recent studies on sample preparation by liquid micro-extraction. However, there are still limitations for its application to seawater, such as the need of additives to preserve the sample or the availability of chemical extractants for the selective extraction from highly saline samples. In this work, a three phase solvent bar micro-extraction (3SBME) system containing the ionic liquid trioctylmethylammonium chloride (Aliquat 336) has been used for isolation and pre-concentration of Cd from seawater samples, due to its ability for ionic exchange of CdCl.

Solvent bar micro-extraction with graphite atomic absorption spectrometry for the determination of silver in ocean water.

Main drawbacks for silver determination in seawater are the effects of samples matrix and that Ag appears in the sub ng L(-1). Available methods for sample preparation in Ag analysis are based on solid and liquid extraction using tedious process that increase the cost of analysis and the risk of sample contamination, producing important waste amounts. Solvent bar micro-extraction (SBME) allows the pre-concentration of Ag in a micro-volume of the ionic liquid Aliquat 336® in kerosene solution.

Solvent bar micro-extraction: Improving hollow fiber liquid phase micro-extraction applicability in the determination of Ni in seawater samples.

During the last decade, hollow fiber liquid phase micro-extraction (HF-LPME) has become an attractive alternative in sample treatment for the analysis of trace metals in seawater. If compared with other similar methodologies, its main advantages are associated to a higher stability of the organic solution contained into the pores of the fiber, which acts as a lipophilic membrane during the extraction process. However there are some remaining problems that makes its use difficult, mostly related to the need of increasing the rate of analysis and improving portability.

Three-phase solvent bar micro-extraction as an approach to silver ultra-traces speciation in estuarine water samples.

Silver ion inputs into the environment due to human activities have been increased in the last years because it has been used as a bactericide with application in medical, homecare and self-care products. In addition, it is toxic at low concentration for aquatic organisms. In estuarine waters, salinity and dissolved organic matter (DOM) regulate Ag(+) concentration by the formation of complexes as AgCln((n-1)-) and Ag-DOM.