The paper presents data on the possibility of ETAAS analysis, and a technique of this analysis, of salt rocks, their insoluble residues, and organic fractions from these rocks for Au, Pt, and Pd (concentrations from 10–7 to 10–2 ppm). Various techniques for the decomposition of the samples are discussed, and the paper presents information on the extent of Au, Pt, and Pd adsorption from chloride complexes when the POLYORGS-IV complex-forming adsorption agent is applied. The determined atomization parameters of the elements in a graphite furnace are reported. Precious metals are proved to be concentrated in the insoluble residues of the salt rocks and in the slimes (salt wastes) when the salt rocks are processed. The forms in which precious metals are contained in the salt-bearing rocks are determined.

Possibilities of the determination of Au, Ag, and Si in dispersions of nanoparticles and biological samples by inductively coupled plasma atomic absorption and atomic emission spectrometry are demonstrated. Conditions of complete sample mineralization and the quantitative transfer of gold and silver to solution are found. The parameters of analyte determination in flame, graphite furnace, and plasma are optimized. The completeness of the atomization of gold, silver, and silicon in plasma on the introduction of nanoparticles as colloidal solutions is estimated. The conducted research allowed the estimation of the degree of gold and silver reduction at different stages of synthesis of composite nanoparticles with the core/shell structure. Quantitative information on the dynamics of accumulation and the redistribution of composite nanoparticles with gold or silver shells in organs and tissues of mices after the intravenous administration of colloidal solutions of nanoparticles.

Aggregative stable dispersions of particles with anisotropic cores of iron(III) oxyhydroxide and gold or silver nanoshells are synthesized. They feature maximum plasmonic absorption at about 1000 nm (i.e., in the “optical window” of biological tissues). Such composite particles are of considerable interest for their potential use in cancer therapy. The possibility of finely tuning the position of localized surface plasmon resonance to the required wavelength is demonstrated for the FeOOH core/Au(Ag) shell nanostructures through a controlled variation of the metal shell thickness with a very small step (up to 1 nm). The surface modification of such composite particles by polyethylene glycol (PEG) considerably enhances the aggregative stability of their aqueous dispersions. Quantitative information about the distribution dynamics of the PEG-conjugated composite FeOOH core/Au shell particles in various organs and tissues of tumor-bearing mice has been obtained after an intravenous injection of a colloid solution of these particles. It is shown that composite particles can remain for a rather long time in a bloodstream without aggregation; moreover, their accumulation in a tumor takes place. Preliminary in vivo experiments have shown that PEGylated FeOOH core/Au(Ag) shell particles are effective thermosensibilizers in the pulse laser therapy of tumors.

A comprehensive technique for determining Ni and V in crude oils in a wide range of their concentrations is described. The procedure involves ETAAS, ICP-AES, and autoclave sample preparation. The optimal conditions for the mineralization of oil samples in Ankon-AT2 analytical autoclaves in a mixture of HNO3 and H2O2 are found. Oil and condensates of oil- and gas-bearing basins are taken as objects of investigation. The concentrations of Ni and V in these systems are estimated and the regularities in the distributions of Ni and V are revealed.

The mathematical model describing strontium sorption by natural zeolite as a geochemical barrier in case of a variable flow rate and two-phase kinetics is defined. The criterion for the selection of the model is to fit the calculations results to a 10% interval of the mean-square deviation of the experimental data.

Advances in plasmonic nanoparticle synthesis and functionalization open new possibilities for biomedical applications, including enhanced cancer therapy by selectively gaining access to tumor due to their small size and modifiability. Herein, we report results encompassing the synthesis and PEGylation of gold nanorods and silica/gold nanoshells and an in vivo pharmacokinetics study of functionalized nanoparticles in tumor-bearing mice.

The solubility of (i) Au(cr), (ii) mixtures of crystalline Ag2S–Ag3AuS2, and (iii) Ag3AuS2 (uytenbogaardtite)–AgAuS (petrovskaite) was measured at 25 °C, 1 bar, whereas the solubility of AgAuS(cr) was measured at 91–250 °C and Psat. These measurements were performed in aqueous sulphide solutions containing ∼0.012–0.12 m of total reduced sulfur. At 25 °C sealed glass ampoules were employed, and Ti autoclaves allowing sampling of experimental solutions were used at higher temperatures. It was found that under investigated experimental conditions AgAuS dissolves incongruently with the formation of Ag3AuS2. The values of the following equilibrium reaction constants were determined:Au(cr)+H2S0(aq)+HS-=Au(HS)2-+0.5H2(g)(i)K(i)=K(Au(HS)2-)Ag3AuS2(cr)+HS-+0.5H2S0(aq)=1.5Ag2S(cr)+Au(HS)2-(ii)K(ii)1.5AgAuS(cr)+HS-+0.5H2S0(aq)=0.5Ag3AuS2(cr)+Au(HS)2-(iii)K(iii) It was found that at 25 °C, 1 bar log K(i) = −5.62 ± 0.14, log K(ii) = −4.49 ± 0.26 and log K(iii) = −4.03 ± 0.15. Solubility data collected at higher temperatures resulted in the following values for log K(iii): −2.12 ± 0.25, −1.32 ± 0.12, and −1.04 ± 0.08 at 91, 150, and 250 °C, respectively (the latter value corresponds to the reaction 1.97 AgAuS(cr)+HS-+0.5H2S0(aq)=0.735 Ag2.68Au1.32S2(cr)+Au(HS)2- because Ag3AuS2(cr) undergoes a phase transition at 183 °C). These values are in good agreement with log K(iii) = −2.81 ± 0.10 obtained at 80 °C by Zotov et al. (Zotov, A.V., Baranova, N.N., Bannykh, L.N., 1996. Solubility of the gold sulfides Au2S and AgAuS in solutions containing hydrogen sulfide at 25–80 °C and pressures of 1 and 500 bar. Geochem. Int. 34, 216–221). The values of K(ii) and K(iii) determined in the present study were combined with the thermodynamic properties of Ag–Au sulphides reported by Osadchii and Rappo (Osadchii, E.G., Rappo, O.A., 2004. Determination of standard thermodynamic properties of sulfides in the Ag–Au–S system by means of a solid-state galvanic cell. Am. Miner. 89, 1405–1410), and thermodynamic properties for aqueous species and hydrogen from SUPCRT92 database to generate the values of K(Au(HS)2-). The results of the three experimental series performed at 25 °C, Psat (involving metallic gold (i) and Ag–Au sulphides (ii) and (iii)) yield the average value of log K(Au(HS)2-)=-5.38±0.25.LogK(Au(HS)2-) values derived at higher temperatures are −3.85 ± 0.20, −3.13 ± 0.29, −2.22 ± 0.20, and −1.96 ± 0.25 at 80, 91, 150 and 250 °C, respectively.At 150 and 250 °C these logK(Au(HS)2-) values are in close agreement with the data of Shenberger and Barnes (Shenberger, D.M., Barnes, H.L., 1989.Solubility of gold in aqueous solutions from 150 to 350 °C. Geochim.Cosmochim.Acta 53, 269–278).The logK(Au(HS)2-) value obtained at 25 °C, 1 bar combined with Au2S(cr) solubility products (Au2S(cr)+3HS-+H+=2Au(HS)2- and Au2S(cr)+HS-+H+=2AuHS0(aq)) measured at 25 °C by Renders and Seward (Renders, P.J., Seward, T.M., 1989.The stability of hydrosulphido- and sulphido-complexes of Au(I) and Ag(I) at 25 °C. Geochim.Cosmochim.Acta 53, 245–253) yields ΔfG(298.15K)o(Au2S(cr))=19.41±1.43kJ/mol and log K(AuHS0) = −10.98 ± 0.30 for the reactionAu(cr)+H2S0(aq)=AuHS0(aq)+0.5H2(g)K(AuHS0).

An approach to studying the elemental composition of cyanobacteria Spirulina platensis and Nostoc commune using a set of complementary analytical methods (ICP–AES, PAAS, and ETAAS) is proposed. The procedures were adapted for the determination of macro- and microelements (Na, K, Mg, Ca, Fe, Mn, Cu, Mo, Zn, B, and Se) in the biomass of cyanobacteria and separated cell fractions (chloroform and water–methanol extracts and precipitates). The conditions for the mineralization of biological materials were optimized for autoclave and microwave sample preparation procedures. The evaporation and atomization of Se and Mo in a graphite furnace in the presence of chloroform and methanol were studied. The use of combined analytical methods and the interpretation of analytical results allow one to draw conclusions about the ability of cyanobacteria to accumulate biologically important microelements (B, Mo, Se, and Zn) and to optimize technological processes for manufacturing biologically active substances.

The use of inductively coupled plasma atomic emission spectrometry in combination with electrothermal atomic absorption spectrometry and autoclave sample preparation essentially improved performance characteristics of the determination of heavy metals and simplified analytical procedures for determining their speciation. Inductively coupled plasma atomic emission spectrometry can give information about the concentrations of a wide range of elements in water and bottom deposits at a level of MPC and, thus, is useful for revealing sources of pollution of water reservoirs. More sensitive electrothermal atomic absorption spectrometry was used for determining background concentrations of Pb, Cd, Co, Ni, Cu, Cr, Mo, and As and assessing the speciation of Pb, Cd, Co, Cu, and Zn in waters and bottom sediments. Based on the results of analyses of surface, bottom, and void waters; bottom sediments and their step-by-step extracts; and KMC and DEAE cellulose adsorbents containing charge-separated heavy metals, the ecological status of Kuibyshev, Ivan’kovo, and Rybinsk water reservoirs was assessed.

A procedure for determining antimony and arsenic in-fresh water, plants, and common salt was developed. The procedure is based on the selective preconcentration of Sb(III) and As(III) dipropyl dithiophosphates from chloride solutions by solid-phase extraction using DIAPAK-C16 cartridges. It is shown that microcolumns with this sorbent can be used for flow preconcentrating antimony and arsenic. Antimony and arsenic are determined in the eluate by electrothermal atomic absorption spectrometry. The relative standard deviation in the determination of antimony and arsenic at the level of 10(-6) to 10(-4)% is 3-7%.

Solubility of the gold sulfide Au2S in 0.0106-0.013 M H2S solutions was studied at 25 degrees C and pH 6.49-6.66. The dissolution of Au2S was demonstrated to proceed to the formation of the Au(HS)(2)(-)-complex. Partial molar volume of the Au(HS)(2)(-)-compmlex, V-25 degrees C,V- 1 bar (0) = 83 +/- 15 cm(3)/mol was determined. Solubility of the gold and silver sulfide AuAgS in 0.003-0.0056 M H2S solutions was studied at 80 degrees C and pressures of 1 and 500 bar over a pH range of 6.57 to 7.00. The data obtained did not contradict the results of the Au2S solubility measurements at 25 degrees C.

It is proved that carboxyl functional groups are present in primary carbonbearing matter of rocks and also in carbonbearing particles activated under the thermal and acid treatment of the samplex of carbonaceous rocks.Sorption of Au(II), Pd(II) and Pt(IV) on carbonbearing particles separated from the gold deposit ore rocks was studied. It is shown that sorption of noble metals is brough about in accordince with complex-forming mechanism. The formation of stable chemical bond with oxygenbearing functional groups of carbonaceous matter is responsible for the possibility of noble metal losses as volatile compounds under the thermal treatment of rock samples and losses on account of sorption of noble metals on carbonbearing particles under acid treatment of samples. These losses could be extimated as 1-2 orders of magnitude at the analyses of carbonaceous rocks. Analytical procedures leading to elimination of losses are suggested.