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The preparation of stable cysteine-capped silver nanoparticles (AgNPs), via the reduction of silver ions with sodium borohydride and modification of formed nanoparticles by l-cysteine, was developed. The micrographs from transmission electron microscopy (TEM) revealed that the spherical AgNPs exhibited an average size equal to 22±4nm. Surface enhanced Raman spectroscopy (SERS) and inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed a chemisorption of cysteine molecules on the AgNPs. Additionally, dynamic light scattering (DLS) measurements showed that the AgNPs were stable for ionic strength lower than 5×10-3molL-1 and at 6.8

In the paper an application of solid phase extraction technique for speciation analysis of manganese in water samples with the use of flame atomic absorption spectrometry is presented. Two types of sorbents, activated silica gel and Dowex 1 × 4, were used respectively for simultaneously Mn 2 + and MnO 4 2 − retention and preconcentration. The whole procedure was realized in multicomutation flow system. Different conditions like: type and concentration of eluent, sample pH and loading time were tested during the study. Under appropriate conditions, it was possible to obtained enrichment factors of 20 and 16 for Mn(II) and Mn(VII), respectively. Precision of the procedure was close to 4% (measured as relative standard deviation), whereas the detection limit (3σ) was 1.4 μg·L − 1 for Mn(II) and 4.8 μg·L − 1 for Mn(VII).

The speciation of Mn(II) and Mn(VII) is reported by ion pair chromatography. To optimize the separation, sample pH, ion pair reagent, Mn(II) complexing agent, and composition of mobile phase were c...

Selenium was determined in serum, hair, and tobacco by inductively coupled plasma-mass spectrometry using 77Se, 78Se, and 82Se. The set of standards method (SSM) and the standard addition method (SAM) were applied to calibration with and without the use of internal standards (72Ge and 103Rh). In addition, the usefulness of the dynamic reaction cell (DRC) with methane as the reaction gas was characterized. The results obtained in different conditions were evaluated in terms of precision and accuracy. It was demonstrated theoretically and experimentally that an internal standard is a potential source of systematic errors as it can be influenced multiplicatively and additively by its own interferents (independently of selenium). Furthermore, it was shown that—against common opinion—an internal standard can fail in elimination of chemical interference effects influencing selenium and in increasing of precision of selenium determinations. The DRC was shown to be effective in the elimination of additive...

The growing popularity of nanomaterials requires a systematic study of their effects on the human body. Silver nanoparticles (AgNPs), due to their antiseptic properties, are used in almost every area of life. The purpose of the study was to examine whether the precursor used for the synthesis of nanoparticles affects their bio-influence and modifies their impact on cells of the human immune system. To compare the effects of precursor silver salts (AgNO3, CH3COOAg and AgClO4) and corresponding nanoparticles (TAN TAA and TAC) cytotoxicity study was conducted on two cell lines U-937 and HL-60. For both cell lines, silver salts are more toxic than the corresponding nanoparticles. Cell viability after treatment with the two forms of silver (salt/particle) is dependent on silver dose and degree of cells differentiation. Addition of the silver salt of doses greater than 5 mg/L results in decreased cell viability by over 60%, whereas nanoparticles' addition reduces cell viability on average by 30%. On the basis of the determined LD50 values it can be stated that for the tested cells the most toxic are AgClO4 and TAC. Production of nitric oxide, which is a mediator of inflammation, is the greatest after treatment of the cells by TAC. Different interactions of studied nanoparticles with albumin has been found and it was shown that addition of albumin to the cells treated by nanoparticles reduces their toxic effects. Obtained by us highly purified, mono-disperse AgNPs exhibit diverse effects relative to the biological systems, depending on the precursor salt used.

Teeth retain different elements at particular stages of life. Hence, the exposure over a selected time span may be characterized by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). A Nd:YAG laser with emission at 266 nm was coupled to a quadrupole ICP-MS for the quantitative study of historical human teeth for Sr and Ba, elements of anthropological significance. A calibration approach incorporating the experimentally derived k coefficient is reported. The coefficients were established based on the mean concentrations of the analytes determined by pneumatic nebulization ICP-MS using acid-digested calcium phosphate standards and the intensities recorded during laser ablation of corresponding standards as pellets. The k values were 0.54 ± 0.05 (µg g−1)−1 and 4.49 ± 1.09 (µg g−1)−1 for Sr and Ba, respectively. This calibration approach provided local quantitative data and demonstrated statistically significant differences in Sr concentrations in enamel and dentine.

A general model of an oxidative dissolution of silver particle suspensions was developed that rigorously considers the bulk and surface solute transport. A two-step surface reaction scheme was proposed that comprises the formation of the silver oxide phase by direct oxidation and the acidic dissolution of this phase leading to silver ion release. By considering this, a complete set of equations is formulated describing oxygen and silver ion transport to and from particles' surfaces. These equations are solved in some limiting cases of nanoparticle dissolution in dilute suspensions. The obtained kinetic equations were used for the interpretation of experimental data pertinent to the dissolution kinetics of citrate-stabilized silver nanoparticles. In these kinetic measurements the role of pH and bulk suspension concentration was quantitatively evaluated by using the atomic absorption spectrometry (AAS). It was shown that the theoretical model adequately reflects the main features of the experimental results, especially the significant increase in the dissolution rate for lower pH. Also the presence of two kinetic regimes was quantitatively explained in terms of the decrease in the coverage of the fast dissolving oxide layer. The overall silver dissolution rate constants characterizing these two regimes were determined.

Recently, many studies have investigated the relationship between the level of metals in the body and various diseases. The objective of this study was to examine any possible influence of periodontal disease upon the concentration of metals in oral fluid and blood and to explore the usability of applying cluster analysis coupled with the analysis of selected elements in oral fluid, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), zinc (Zn), cadmium (Cd) and lead (Pb), for effectively distinguishing people affected by periodontitis from healthy individuals. The quantification of eight metals in oral fluid and blood samples was performed by two inductively coupled plasma techniques–inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Most of the examined elements were detected at elevated concentration in the oral fluid of periodontal patients. However, the differences were statistically significant in the case of three metals: Cu, Mg and Mn (p

Here a new flow injection system is reported for the preconcentration of technetium by solid phase extraction. The system provides analyte preconcentration, reduces interferences from polyatomic ions, and prevents interaction of concentrated nitric acid with the inductively coupled plasma mass spectrometer. The volume of eluate was significantly reduced by collecting the eluate of the highest analyte concentration in an injection loop followed by transport to the spectrometer with dilute nitric acid. Due to the absence of a suitable standard reference material, the determination of technetium in peat was compared with liquid scintillation spectrometry.

Manganese as an essential element is required by organisms from simple bacteria to plants, animals and human beings. The identification and determination of organic or inorganic manganese forms are important from many viewpoints, such as their bioavailability or bioactivity. A review of the use of different analytical methods, which allow manganese speciation and fractionation in various types of matrices, such as soils, sediments, air, aerosols, water, plants, animals and polluted environmental samples, is presented in this study. The presented approaches assume mainly the use of indirect techniques from simple ones, such as extraction, through multistep procedures to more complex ones, such as hyphenated techniques. Direct analysis of manganese species is also possible, but unfortunately only in some cases and for selected samples. Significance of manganese speciation and fractionation in different areas of life and difficulties in performing such analysis pose a challenge.

Head and neck cancers are one of the most frequent cancers worldwide. This paper attempts to evaluate disturbances of homeostasis of the necessary elements (calcium, magnesium, zinc, copper, iron, manganese) and changes in the levels of toxic metals (lead, cadmium, cobalt, chromium VI) in hair of patients with head and neck cancers, as well as people without a diagnosed neoplastic disease. In order to quantify the necessary elements and toxic metals, a method using ICP-MS and ICP-OES techniques had been developed and validated. The studies have shown that patients with head and neck cancer used to drink alcohol and smoked much more frequently than healthy individuals, both in the past and presently. Statistically significant differences in concentrations of average metal content in the group of patients with head and neck cancers compared to the control group were confirmed. Significant differences in metal content between the group of patients with head and neck cancers and healthy individuals were found which enabled distinguishing between the study groups. To this end, a more advanced statistical tool, i.e. chemometrics, was used. The conducted research analyses and the use of advanced statistical techniques confirm the benefits of using alternative material to distinguish the patients with head and neck cancers from the healthy individuals.

Manganese, a microelement important for plant metabolism, when accumulated at higher doses, may act as a stress factor. Such action of this element is not fully recognized and is currently being intensively studied. The influence of manganese, at high (1, 2 and 3 mM) concentrations, on the induction of oxidative stress in wheat cells was studied under in vitro conditions. Calli of two wheat cultivars, different in terms of stress tolerance, were cultured for 7 days on Murashige–Skoog media with or without auxin (2,4-D) and with additional Mn supplementation. Changes of malondialdehyde (MDA) concentration and the activity of enzymes (SOD, CAT and POX) involved in oxidative response as well as the accumulation of Mn and elements essential for plant development (Mn, Mg, S, Ca, K, P, Na, Zn, Mo, Cu, Fe) were detected. Moreover, proline and carbohydrate contents were determined to check the induction of osmotic stress. An increase of lipid peroxidation (expressed by MDA content), induced by ROS generation, was smaller in the tolerant (‘Parabola’) cultivar than in the sensitive one (‘Raweta’). The activation of antioxidative enzymes was more effective in the cells of tolerant wheat, where a lower quantity of Mn was accumulated. Mn uptake was correlated with a decrease of an amount of almost all the investigated elements. Auxin presence in the culture media accelerated the stressogenic effect of Mn.

Effects related to the adaptation of wheat to Mn excess were determined by structural and biochemical characterization of chloroplasts obtained from three-leaf seedlings of Mn-treated wheat. Chloroplasts were isolated from two wheat genotypes: sensitive (Raweta) and tolerant (Parabola) cultivated in hydroponic conditions in Hoagland nutrient supplemented with 0 (control), 5, 10, and 20 mmol dm−3 MnSO4. Microscopic observations of the chloroplast structure revealed differences in the size and starch presence between both objects. Changes indicating the stresogenic influence of Mn on Raweta seedlings appeared already at the Mn dose of 10 mmol dm−3, whereas on Parabola, only at 20 mmol dm−3. Biochemical analysis indicated the differences in starch content. Results of measurements of lipid peroxidation, polarity, and electrokinetic potential of chloroplasts point to Mn-stimulated modifications of chloroplast membranes which occurred to be larger for Raweta. The activation of antioxidative enzymes (SOD and POX) shows that ROS are generated under Mn-excess conditions. The content of Mn and Cu, Fe, Mo, and Zn (microelements) as well as Ca, Mg, K, P, and S (macroelements) in chloroplasts was determined by mass (ICP MS) and plasma optic emission (ICP OES) spectrometry. Raweta accumulated greater amount of Mn in comparison with Parabola at all Mn doses in media. Increased concentration of Mn was accompanied with a decrease of uptake other investigated elements (except for K).