Analysis of Engineered Nanoparticles in Seawater Using ICP-MS-Based Technology: From Negative to Positive Samples

A growing global emission of engineered nanoparticles (ENPs) into the aquatic environment has become an emerging safety concern that requires methods capable of identifying the occurrence and possibly determining the amounts of ENPs. In this study, we employed sector-field inductively coupled mass spectrometry to assess the presence of ENPs in coastal seawater samples collected from the Black Sea in regions suffering different anthropogenic impacts. Ultrafiltration through commercial 3 kDa membrane filters was shown to be feasible to separate the ENPs from the bulk seawater, and the subsequent ultrasound-mediated acidic dissolution makes the metals constituting the ENPs amenable to analysis. This procedure allowed the ENPs bearing Cu, Zn, V, Mo, and Sn to be for the first time quantitated in seashore surface water, their concentration ranging from 0.1 to 1.0 μg L−1 (as metal) and related to the presence of industry and/or urban stress. While these levels are decreased by natural dilution and possible sedimentation, the monitored ENPs remain measurable at a distance of 2 km from the coast. This can be attributed not only to local emission sources but also to some natural backgrounds

Sensitive determination of anions in saliva using capillary electrophoresis after transient isotachophoretic preconcentration

A transient isotachophoresis-capillary electrophoresis (tITP-CE) system for the determination of minor inorganic anions in saliva is described. The complete separation and quantification of bromide, iodide, nitrate, nitrite, and thiocyanate has been achieved with only centrifugation and dilution of the saliva sample. In-line tITP preconcentration conditions, created by introduction of the plugs of 5 mM dithionic acid (leading electrolyte) and 10 mM formic acid (terminating electrolyte) before and after the sample zone, respectively, allowed the limits of direct UV absorption detection (at 200 nm) to be up to 50-fold improved as compared with CE without tITP. As a result, nitrate and thiocyanate were still detectable at 4.6 and 3.8 µg l-1, respectively, in 1000 times diluted saliva. The daily variations of anionic concentrations in saliva samples taken from a smoking health volunteer were discussed based on the results of tITP-CE analysis. It was confirmed that the thiocyanate concentration in saliva noticeably increased after smoking. This is apparently the first report on simultaneous quantification of more than four anionic salivary constituents using CE

Analysis of Engineered Nanoparticles in Seawater Using ICP-MS-Based Technology: From Negative to Positive Samples

A growing global emission of engineered nanoparticles (ENPs) into the aquatic environment has become an emerging safety concern that requires methods capable of identifying the occurrence and possibly determining the amounts of ENPs. In this study, we employed sector-field inductively coupled mass spectrometry to assess the presence of ENPs in coastal seawater samples collected from the Black Sea in regions suffering different anthropogenic impacts. Ultrafiltration through commercial 3 kDa membrane filters was shown to be feasible to separate the ENPs from the bulk seawater, and the subsequent ultrasound-mediated acidic dissolution makes the metals constituting the ENPs amenable to analysis. This procedure allowed the ENPs bearing Cu, Zn, V, Mo, and Sn to be for the first time quantitated in seashore surface water, their concentration ranging from 0.1 to 1.0 μg L−1 (as metal) and related to the presence of industry and/or urban stress. While these levels are decreased by natural dilution and possible sedimentation, the monitored ENPs remain measurable at a distance of 2 km from the coast. This can be attributed not only to local emission sources but also to some natural backgrounds

Nanoscale Ion-Exchange Materials: From Analytical Chemistry to Industrial and Biomedical Applications

Nano-sized ion exchangers (NIEs) combine the properties of common bulk ion-exchange polymers with the unique advantages of downsizing into nanoparticulate matter. In particular, being by nature milti-charged ions exchangers, NIEs possess high reactivity and stability in suspensions. This brief review provides an introduction to the emerging landscape of various NIE materials and summarizes their actual and potential applications. Special attention is paid to the different methods of NIE fabrication and studying their ion-exchange behavior. Critically discussed are different examples of using NIEs in chemical analysis, e.g., as solid-phase extraction materials, ion chromatography separating phases, modifiers for capillary electrophoresis, etc., and in industry (fuel cells, catalysis, water softening). Also brought into focus is the potential of NIEs for controlled drug and contrast agent delivery

Simultaneous monitoring of inorganic cations, amines and amino acids in human sweat by capillary electrophoresis

The determination of cationic constituents of sweat is widely recognized as a difficult analytical task due to its complex composition and minute sample volumes available for the individual analysis. Capillary electrophoresis (CE) has been evaluated as a simple routine method to measure sweat metal cations, biogenic amines, and amino acids using a sampling procedure previously developed in one of collaborative teams. The carrier electrolyte, which consisted of 10 mM 4-methylbenzylamine, 6.5 mM α-hydroxyisobutyric acid, and 2 mM 18-crown-6 at pH 4.25 allowed the separation of five cations (NH4+, K+, Ca2+, Na+, Mg2+) and four amino acids (ornithine, histidine, lysine, arginine) to be completed in about 13 min with a positive polarity of the applied voltage (30 kV). By increasing the sample volume (due to employing hydrodynamic instead of hydrostatic injection mode), it was also possible to detect indirect UV signals of Zn2+, diethanolamine, and trietanolamine. Sweat samples were collected from the fingers and forearms of three healthy male volunteers and analyzed by CE. A good repeatability and reproducibility of peak area responses based on five intraday and three inter-day assays (average %RSD less than 3.5 and 2.5, respectively) were obtained. The limits of detection were in the range of 3.2-5.8 μM for alkali and alkaline-earth cations (hydrostatic injection) and 0.27-0.79 μM for other target analytes (hydrodynamic injection). The analytical results for particular analytes were found to vary, depending on the sampling spot and individual, but in general correspond well to clinical concentration ranges