Determination of size and particle number concentration of metallic nanoparticles using isotope dilution analysis combined with single particle ICP-MS to minimise matrix effects.

Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is a powerful tool for metallic nanoparticle (NP) characterisation in terms of concentration and, taking into account several assumptions, also size. However, this technique faces challenges, such as the intrinsic matrix effect, which significantly impact the results when analysing real complex samples. This issue is critical for the calculations of key SP-ICP-MS parameters ultimately altering the final outcomes.

Electrical asymmetrical flow field-flow fractionation: Fundamentals, evolution, applications, and prospects.

Among the plethora of techniques that conforms the Field-Flow Fractionation (FFF) family, electrical field-flow fractionation (ElFFF) was designed to separate different analytes based on their size and electrophoretic mobility (µ). However, major technical and operational issues made this technique to fall into oblivion. Many of those drawbacks can be circumvented if another field is employed as the main driving force for the elution in the same channel, such as the most successful and useful FFF-related technique, asymmetrical flow field-flow fractionation (AF4).

Critical evaluation of the potential of ICP-MS-based systems in toxicological studies of metallic nanoparticles.

The extensive application of metallic nanoparticles (NPs) in several fields has significantly impacted our daily lives. Nonetheless, uncertainties persist regarding the toxicity and potential risks associated with the vast number of NPs entering the environment and human bodies, so the performance of toxicological studies are highly demanded. While traditional assays focus primarily on the effects, the comprehension of the underlying processes requires innovative analytical approaches that can detect, characterize, and quantify NPs in complex biological matrices.

Critical evaluation of key parameters in single particle ICP-MS data processing for the correct determination of platinum nanoparticles in complex environmental and biological matrices.

There is an urgent need for the harmonization of critical parameters in single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) and they have been deeply studied and optimized in the present work using platinum nanoparticles (PtNPs) as a representative case of study. Special attention has been paid to data processing in order to achieve an adequate discrimination between signals. Thus, a comparison between four different algorithms has been performed and the method for transport efficiency calculation has also been thorougly evaluated (finding the use of a well-characterized solution of the same targeted analyte (30 nm PtNPs) as adequate).

Electrical asymmetric-flow field-flow fractionation with a multi-detector array platform for the characterization of metallic nanoparticles with different coatings.

Electrical asymmetric-flow field-flow fractionation (EAF4) is a new and interesting analytical technique recently proposed for the characterization of metallic nanoparticles (NPs). It has the potential to simultaneously provide relevant information about size and electrical parameters, such as electrophoretic mobility (μ) and zeta-potential (ζ), of individual NP populations in an online instrumental setup with an array of detectors. However, several chemical and instrumental conditions involved in this technique are definitely influential, and only few applications have been proposed until now.

Prevalence of Heterotrophic Methylmercury Detoxifying Bacteria across Oceanic Regions.

Microbial reduction of inorganic divalent mercury (Hg) and methylmercury (MeHg) demethylation is performed by the operon, specifically by and genes, respectively, but little is known about the mercury tolerance capacity of marine microorganisms and its prevalence in the ocean. Here, combining culture-dependent analyses with metagenomic and metatranscriptomic data, we show that marine bacteria that encode genes are widespread and active in the global ocean. We explored the distribution of these genes in 290 marine heterotrophic bacteria ( and spp.

Assessing mercury intoxication in isolated/remote populations: Increased S100B mRNA in blood in exposed riverine inhabitants of the Amazon.

Mercury is a heavy metal responsible for human intoxication worldwide and especially in the Amazon, where both natural and anthropogenic sources are responsible for exposure in riverine populations. Methylmercury is the most toxic specie of mercury with recognized neurotoxicity due to its affinity for the central nervous system. S100B protein is a well-established biomarker of brain damage and it was recently associated with mercury-related neurotoxicity.

Mercury species accumulation and distribution in Typha domingensis under real field conditions (Almadén, Spain).

Monomethylmercury (MeHg) is one of the most toxic and the most commonly occurring organomercury compound and the wetlands are one of the main areas of generation of this Hg form. Concretely, it is in the macrophyte root system where better conditions are given for its generation. However, the knowledge of absorption and subsequent distribution of mercury (Hg) and monomethylmercury in aquatic plants is still limited.

Fast method for the simultaneous determination of monomethylmercury and inorganic mercury in rice and aquatic plants.

Recent investigations revealed that monomethylmercury (MMHg) can be absorbed and accumulated by plants, i.e. rice crops, thus becoming an important route of human exposure to MMHg through diet.

Astaxanthin and papilioerythrinone in the skin of birds: a chromatic convergence of two metabolic routes with different precursors?

Carotenoids are organic pigments involved in several important physiological functions and may serve as indicators of individual quality in animals. These pigments are only obtained by animals from the diet, but they can be later transformed into other carotenoids by specific enzymatic reactions. The diet of farm-reared and probably wild red-legged partridges (Alectoris rufa) is mainly based on cereals that contain high levels of lutein and zeaxanthin.

Multiresidue determination of organochlorines in fish oil by GC-MS: a new strategy in the sample preparation.

A rapid, economic and environmentally friendly analytical methodology has been implemented for the determination of alpha-, beta-, gamma- and delta-HCH, p,p'-DDT, p,p'-DDD and p,p'-DDE, PCBs congeners #28, #52, #101, #153, #138 and #180 and Hexachlorobenzene in fish oil. 1,2,3,4-Tetrachloronaphtalene was used as internal standard. The sample preparation, consisting of a single step of clean-up and fractionation, took place in a column filled with different layers of neutral and sulphuric acid modified silica.

Determination of mercury species in fish reference materials by gas chromatography-atomic fluorescence detection after closed-vessel microwave-assisted extraction.

A simple and rapid method has been developed for speciation analysis of inorganic mercury and monomethylmercury (MMHg) in biological tissues. The procedure is based on the quantitative closed-vessel microwave-assisted leaching of mercury from biological samples with an alkaline extractant. The extracted mercury species are ethylated and analysed by capillary gas chromatography coupled to an atomic fluorescence detector via pyrolysis (CGC-pyro-AFS).