Thiosulfate Salts Research Articles

Forensic implication of seized drug imitating methamphetamine with mileage in crime

BackgroundThe increase in drug abuse a major global issue. Clandestine laboratories along with illegal drug trafficking and trade increase the menace. Increased confiscation of illicit drugs not only indicates the manifold rise in drug abuse in Delhi and its neighboring region but also signifies an escalation and proliferation in other drug-related criminal activities. Investigating agencies around the world are working hard to combat and eradicate this problem. The samples seized by these agencies are subsequently sent for forensic examination to rule out the presence of any illicit drugs. Few such seized crystalline samples such as “methamphetamine” were submitted for examination with a query for the identification of any scheduled substance. The analysis outline followed was physical, chemical, Fourier transform infrared spectrometer analysis for detection, identification, and confirmation of seized drug samples. The purpose of a detailed investigation regarding the identification of the crystalline sample was also to understand the criminal activities involved in the consistent seizures and the forensics behind it.ResultsThe comprehensive examination identified the sample as an inorganic salt of sodium thiosulfate with the absence of contraband methamphetamine. The study on salt-imitating methamphetamine underlines its diverse uses as in adulteration, trafficking to camouflage narcotics drug and its involvement in numerous other illegal purposes which on the other hand has a very crucial impact on society and its well-being.ConclusionsThe novel findings will update the investigating agencies and other experts regarding the importance of the detection of sodium thiosulfate salt in seized samples and will well establish the foul play behind large seizures to justify the role of forensic science. This unique finding deals with a very sensitive issue that has immense social impact and needs exceptional thoughtfulness.

Heterogeneous interface of Ni-Mn composite Prussian blue analog-coated structure modulates the adsorption and conversion of polysulfides in lithium-sulfur batteries

Capacity reduction mainly caused by the shuttle effect and low conductivity restricts the commercial application of lithium-sulfur batteries (LSBs). In this work, a nickel-compound manganese Prussian blue analog-coated polypyrrole composite sulfur electrode material (3-MnNi-PBA@S@PPy) was synthesized. The composite 3-MnNi-PBA@S@PPy has strong chemisorptions to polysulfides (LiPSs) and excellent catalytic activity, which can anchor LiPSs and accelerate their conversion. The surface 3-MnNi-PBA in the 3-MnNi-PBA@S@PPy structure spontaneously reacts with polysulfides to form heterogeneous intermediate phase thiosulfate salts, which can accelerate the conversion of polysulfides. On the basis of the above advantages, 3-MnNi-PBA@S@PPy composites were used as cathodes for LSBs. A high initial capacity of 1285 mAh/g and excellent cycling stability were harvested at a current density of 0.1 C, and the decay rate was only 0.07% per cycle at a high current density of 0.5 C and 500 cycles. The MnNi-PBA material possesses a unique heterogeneous interface catalytic mechanism and effectively suppresses the shuttle effect of LSBs, which has a huge potential application prospect.

Extraction of antibiotics using aqueous two-phase systems based on ethyl lactate and thiosulphate salts

Ethyl lactate is a hydrophilic solvent produced from bio-renewable sources (bioethanol and lactic acid produced from corn fermentation) that is considered as a “green” solvent due to its extremely low toxicity, biodegradability and negligible eco-toxicity.This work focuses on the utilization of ethyl lactate to form aqueous two-phase systems (ATPS) in the presence of inorganic salts for the extraction of antibiotics from aqueous solutions. The performance of three thiosulfate salts (Na2S2O3, K2S2O3 and (NH4)2S2O3) as salting-out media for the extraction of chloramphenicol and tetracycline from their aqueous solutions was examined. In this respect, cloud points for the ternary solutions composed of ethyl lactate, water and salt were determined at atmospheric pressure (0.1 MPa) and 298.2 K. Partition coefficients of chloramphenicol and tetracycline between the two phases were determined by chemical analysis of phases in equilibrium for different initial compositions at 298.2 K. This paper is the first report to demonstrate the ability of the ATPS based on ethyl lactate to efficiently separate antibiotics. Thus, ATPS based on ethyl lactate represents a new and green platform for the extraction of antibiotics from aqueous solutions which can facilitate their detection, identification and quantification in surface waters as well as their extraction from fermentation broths.

The first effective utilization of activated carbon in gold thiosulfate system: A more eco-friendly, easier method for gold recovery and material regeneration

Employing activated carbon in the thiosulfate process has high potential applications for extracting gold. However, formidable challenges must be overcome to achieve such an application in an efficient and eco-friendly manner. Accordingly, this study aimed to develop a simple and environmentally friendly method for gold extraction. To this end, activated carbon with good gold capacity (15.9 kg/t) was synthesised for the first time by impregnating green reagent 1-methyl-5-mercapto-1,2,3,4-tetrazole (MMT), which can thermally decompose into a gas completely, and the mechanisms of adsorption and desorption process were studied. Acceptable desorption efficiency (nearly 100% in 12 h) was achieved for gold on activated carbon using environmentally safe and low-cost thiosulfate salt. More importantly, after gold desorption, the good gold adsorption performance (gold capacity of 13.8 kg/t) of activated carbon could be restored by treating it again with MMT. Additionally, green thiosulfate could be used not only as a leaching agent but as a desorbent for gold. Moreover, the results suggest that gold adsorption on MMT-AC takes place through a ligand exchange mechanism. Overall, the method reported herein exhibits good gold adsorption-desorption performance, while offering environmental friendliness and simplicity. With these achievements, this study is expected to accelerate the development of the expected potentially more environmentally friendly technology.

A Practical and Versatile Method for the C–H Sulfenylation of Imidazo[1,2-a]pyridines

Imidazo[1,2-a]pyridines are an important class of heterocycles that are prevalent in many bioactive small molecules. We report the direct introduction of a broad selection of aromatic, heteroaromatic, or alkyl fragments connected by a thioether group into these important heterocycles by using readily prepared thiosulfate salts.

Trends in Carbon Dioxide (CO2) Fixation by Microbial Cultivations

Biological route is one of the viable options to mitigate CO2 from its point sources. The major purpose of the review article is to discuss the possible utilization of microbial cultures for the mitigation of CO2. The article also highlights the scaling-up approach for biological processes especially when microbial cultures are utilized for the same. Few recent studies reported the chemoautotrophic fixation of CO2(g) by catalyzing thermodynamically favored but kinetically inhibited oxidation-reduction or electron donor-acceptor scheme of dissolved inorganic compounds. The previous studies have confirmed the utilization of different bacterial strains for the mitigation of 5%, 10%, and 15% CO2(g) in the absence of light and its simultaneous conversion into valuable products in the lab scale bioreactor. The recent studies also revealed the possibility of prokaryotes to assimilate CO2(g) via carbon concentration mechanism (CCM). The article summarizes the biological route for the natural assimilation of CO2(g) into biomass at the expense of very less energy penalty, via photoautotrophy and chemolithotrophy. The chemolithotrophs utilizes different concentrations of CO2 and thiosulfate salts as an energy source for the non-photosynthetic process. The identification of products using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GCMS) studies is also entailed. The concept of material balance approach is explained to established the mechanism of CO2(g) mitigation through bacterial route. The obtained results pave the way for further development of CO2 utilization technology at larger scales.

Simultaneous removal of SO2 and NOx from flue gas using (NH4)2S2O3/steel slag slurry combined with ozone oxidation

The use of thiosulfate salt (S2O32−), a low-cost reductant, as an absorbent for NO2 removal has been rarely reported. In this study, we propose a method that combines ozone oxidation and (NH4)2S2O3/steel slag slurry spraying to simultaneously remove sulfur dioxide (SO2) and nitrogen oxides (NOx) from flue gas. We investigated the effects of operation conditions on the simultaneous removal efficiencies of SO2 and NOx. Results showed that SO2 removal efficiency was affected by pH, whereas NOx removal efficiency was mostly influenced by (NH4)2S2O3 concentration, reaction temperature, and pH level. Under optimal operation conditions, removal efficiencies of almost 100% for SO2 and above 78.0% for NOx were achieved. NH4+ in the steel slag slurry could tolerate high NO2− concentrations (up to 3.00 mol/L), and the co-existence of NH4+ and S2O32− had a significant synergistic effect on NOx removal. Together with S2O32−, Mg2+ that leached from the steel slag also had a synergistic effect on NO2 removal. We established the reaction mechanisms for NOx removal using (NH4)2S2O3/steel slag slurry. In this process, S2O32− acted as a reducing agent and an oxidation inhibitor of SO32−, thereby enhancing NO2 removal. Moreover, NH4+ inhibited the denitration product (NO2−) from decomposing into NO and NO2, thereby accelerating NOx removal.

Optimization of Microbial Synthesis of Silver Sulfide Nanoparticles

The method for the biosynthesis of silver sulfide nanoparticles using a strain of Shewanella oneidensis MR-1 in an aqueous solution of silver nitrate and sodium thiosulfate salts has been optimized. Optimization is associated with the biosynthesis of nanoparticles directly in the culture medium in the presence of live cells, which increases the nanoparticle yield by 15–20% and significantly shortens the entire process of obtaining nanoparticles. It was also shown that an increase in the concentration of sodium thiosulfate and silver nitrate salts from 1 mM to 10 mM increases the nanoparticle concentration in the reaction solution, whereas the nanoparticle yield in terms of the silver introduced in the reaction decreases. The nanoparticles obtained by the optimized and the conventional methods do not differ in shape, size, and chemical composition. It was shown that the efficiency of nanoparticle biosynthesis depends on the composition of the liquid nutrient medium for S. oneidensis MR-1 cell growth. Cell culturing in nutrient medium for over 24 h fails to intensify the biosynthesis process.

Accounting for Different Reactivities of Sulfinate and Thiosulfate Salts in Regioselective Azetidine Coupling via C–H Sulfenylation of Indoles

The regioselective incorporation of azetidines into heteroaromatic compounds is reported via a formal C–H sulfenylation reaction. While sodium sulfinate salts undergo C3 sulfenylation of electron-rich indoles only, the corresponding thiosulfate salts have proved to be more generally useful. A mechanistic hypothesis for the different reactivities of sulfinate and thiosulfate salts is provided.

Controllable Sulfoxidation and Sulfenylation with Organic Thiosulfate Salts via Dual Electron- and Energy-Transfer Photocatalysis

Sulfoxides and sulfides are two important functional groups in organic molecules, containing different valence states of sulfur. Both sulfoxidation and sulfenylation with common sulfurating reagents were successfully tuned via a facile variation of the atmosphere under photocatalyzed conditions. The sulfoxidation and sulfenylation transformations involved tandem electron-/energy-transfer and single-electron-transfer processes, respectively. Late-stage sulfoxidation for pharmaceuticals and sugar derivatives was established to be highly compatible. Divergent formal syntheses of sulfoxide/sulfide-containing marketed pharmaceuticals were switchably implemented. Gram-scale operations further demonstrated the practicability of the protocol.

Study on the Leaching of Mercuric Oxide with Thiosulfate Solutions

Mercury is receiving more concern due to its high mobility and high toxicity to human health and the environment. Restrictive legislations and world-wide efforts have been made on mercury control, especially the release and disposal of mercury-contaminated wastes. This paper describes a novel technology for detoxifying mercury-containing solid wastes with thiosulfate salts. Various parameters which may potentially influence mercury extraction from mercuric oxide with the thiosulfate leaching system—including reagent concentration, solution pH, and temperature—have been examined. The experimental results show that virtually all mercuric oxide can rapidly dissolve into the thiosulfate leaching system under optimized experimental conditions, indicating that thiosulfate is an effective lixivant for recovering mercury from mercury-containing solid waste.

Role of Thiosulfate in the Corrosion of Steels: A Review

Thiosulfate salts have been known to be dangerous corrosion promoters for over 30 y, when present under typical service conditions. This paper reviews the role of thiosulfate anion in causing localized corrosion and/or stress corrosion cracking of steels. Electrochemical and mechanical aspects associated with the pitting and stress corrosion cracking of steels in thiosulfate-containing environments are thoroughly discussed and reviewed. In particular, results from the research studies relevant to pulp and paper, oil and gas, and nuclear industries, where thiosulfate ion is known to be present advertently or inadvertently, have been analyzed.

Degradation of ethyl xanthate in flotation residues by hydrogen peroxide

The degradation behavior of ethyl xanthate (EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydrogen peroxide (H2O2) was investigated by UV-visible spectroscopy (UV/Vis) at different pH values from 3 to 12. For pH value from 5 to 12, EX was oxidized into ethyl per xanthate (EPX) by H2O2. Then EPX was further oxidized into thiosulfate (TS) salt rather than ethyl thiocarbonate (ETC) and this step was the reaction-limited step. Then depending on pH values, TS was degraded into sulphate and carbonate salts (pH>7) or elemental sulfur (pH 3.0 during test time.

“Surface-enhanced Raman spectroscopy studies of the passive layer formation in gold leaching from thiosulfate solutions in the presence of cupric ion”

Complementary electrochemical and spectroscopic techniques were used to characterize the behavior and composition of the passive layer formed at the gold surface in a thiosulfate electrolyte in the presence of cupric ions. Raman studies of three different cationic (calcium, ammonium, and sodium) thiosulfate leaching solutions revealed that the concentrations of thiosulfate, trithionate, sulfate, and tetrathionate remained constant in the bulk solution over a 3-h time period. The initial leaching current densities of these three systems were identical; however, significant differences in the open circuit potentials of these systems were observed. To provide additional information about the nature of the passive layer, gold nanorod array electrodes were fabricated and employed as substrates for studying the species present at the gold–thiosulfate interface using surface-enhanced Raman spectroscopy (SERS). The composition and behavior of the passive layer at the gold–thiosulfate interface greatly differed from those of the bulk solutions. The passive layer consisted primarily of elemental sulfur and sulfide-like species, with thiosulfate and its oxidation products, such as tri- and tetrathionates, as minority components. The nature of the cation (calcium, sodium, or ammonium) of the thiosulfate salt showed no significant effect on the composition of the passive layer at leaching times longer than 100 min. In addition, the presence of cupric ions also had no significant effect on the formation of the passive layer. However, copper is a much better oxidant than oxygen in gold–thiosulfate leaching reactions.

Sodium thiosulfonate salts: Molecular and supramolecular structural features and solution radiolytic properties

Three sodium thiosulfonate salts, NaMeS(2)O(2)·H(2)O, NaPhS(2)O(2) and NaMeC(6)H(4)S(2)O(2) have been prepared by the direct reaction of the sodium sulfinate salts with elemental sulfur, a clean, benign route that produces no by-products. The structures of the phenyl (which crystallised as a hydrate, NaPhS(2)O(2)·1.5H(2)O) and p-tolyl compounds were determined by X-ray crystallography. For the p-tolyl derivative, NaMeC(6)H(4)S(2)O(2), the unexpected coordination of the pendant sulfur atom was found, a feature not reported previously for thiosulfonate salts, and observed only in two of the more common thiosulfate salts. Intermolecular CH/π interactions are postulated to contribute to the driving force of sulfur coordination, otherwise a different orientation of the aromatic rings would be expected. For NaPhS(2)O(2)·1.5H(2)O, the water ligands and thiosulfonate anions each contribute three oxygen atoms to form a NaO(6) coordination sphere. The thiosulfonate and water oxygens bridge to other sodium atoms forming a three-dimensional layer structure consisting of sheets of NaPhS(2)O(2)·1.5H(2)O with a hydrophilic interior layer, comprising the sodium ions, water ligands and -S(2)O(2)(-) groups, and a hydrophobic exterior formed by the phenyl substituent. The structure is further stabilised by an extensive H-bonding network between the ligated water and the non-coordinating thiosulfonate sulfur atom forming part of the hydrophilic layer and by weak intermolecular edge-to-face CH/π interactions between the sheets. Investigation of the radical chemistry of the three salts using pulse radiolysis indicated that oxidation of NaMeS(2)O(2)·H(2)O involves formation of a sulfur-centred radical rather than hydrogen abstraction from the methyl substituent, whereas oxidation of the aromatic ring is the preferred pathway for the phenyl and p-tolyl derivatives.

Diameter-selected synthesis of single crystalline trigonal selenium nanowires

A low temperature hydrothermal synthesis route has been proposed to the direct production of high purity trigonal selenium nanowires using selenite and thiosulfate salts as starting materials. By choosing different reducing agent, the diameter of the products can be selectively controlled in the range of 10–60 nm. The selenium nanowires synthesized by the present method are free from any catalyst or template, which is beneficial to the future use in related applications.

Dosimetry of a thyroid uptake detected in seed migration survey following a patient's iodine‐125 prostate implant and in vitro measurements of intentional seed leakages

As a quality control procedure, a post-implant seed migration survey has been accomplished on 340 prostate cancer patients since November 2001. Pulmonary seed embolization and intracardiac seed embolization have been detected. A case of thyroid uptake due to leaking iodine-125 (I-125) sources was also seized. In order to determine the dose to the thyroid, a dosimetry method was developed to link in vivo measurements and the cumulated dose to the thyroid. The calculated source leakage half-life in the case was approximately 15 days based on the measurements and the estimated cumulated dose to thyroid was 204 cGy. It is concluded that one seed was leaking. In order to verify the in vivo measurements, intentional in vitro seed leakage tests were performed. A seed was cut open and placed in a sealed glass container filled with a given volume of saline. The I-125 concentration in the saline was subsequently measured over a period of six months. Consistent in vivo and in vitro results were obtained. Recent incidents of seed leaks reported from other centers have drawn practitioners' attention to this problem. In order to make the measurements more useful, the seed leakage tests were expanded to include I-125 seeds from six other vendors. The results show that the leakage half-lives of those seeds varied from nine days to a half-year. Two seed models demonstrated least leakage. Since the measurements lasted for six months, the escape of iodine resulted from oxidation of iodide in the saline was a concern for the measurement accuracy. As a reference, another set of leakage tests were performed by adding sodium thiosulfate salt (Na2S2O3 x 5 H2O) to the saline. Sodium thiosulfate is a reducing agent that prevents the conversion of iodide to iodate so as to minimize I-125 evaporation. As a result, significantly shortened leakage half-lives were observed in this group. Seed agitation was also performed and no significant deviations of the leakage rates were observed. Considering the body fluid is more complex than saline, the in vivo leakage half-life, in case a source leak is encountered, may vary significantly from what is presented in this paper due to chemical reactions. In vivo measurements thus may produce a more accurate estimation of leakage half-life and thyroid uptake dose.

Potassium iodate–initiated polymerization of aniline

Potassium iodate–initiated polymerization of aniline was carried out in an acidified aqueous medium in the presence and in the absence of sodium thiosulfate salt. The nature of the polyaniline (PANI) produced depended on the aniline/potassium iodate (A/PI) mole ratio. Green emeraldine salt (ES) and blue pernigraniline salt (PS) were produced at A/PI mole ratios greater than 2 and less than 2, respectively. The sodium thiosulfate salt played a significant role in the purification and properties of PANI. The optimum aniline-to-oxidant mole ratio was found to be 2 : 1. Spectral, thermal, and electrical characteristics and viscosity of the materials were studied and compared with the results. A reaction scheme has been proposed to elucidate the role of iodine(V). Sodium thiosulfate makes it easier for iodine to be separated from a system and increases the conductivity of the products. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1626–1631, 2007

Kinetic model for anodic oxidation of gold in thiosulfate media based on the adsorption of MS 2O 3− ion-pair

It has been the general practice amongst researchers to use the molar concentration of thiosulfate salts to be the same as that of S 2O 3 2− ions involved in various equilibrium or rate expressions for interpreting gold oxidation kinetics. However, chemical speciation analysis based on the association of thiosulfate ion with monovalent cations (ion-pair formation) shows that the concentration of free S 2O 3 2− ions is lower than that of associated MS 2O 3 − ions (M=Na, K, NH 4). Analysis of literature data on electrochemical oxidation rates of gold in non-ammoniacal alkaline sodium thiosulfate solutions based on the adsorption of NaS 2O 3 − shows that the rate constant for gold oxidation is 4.2×10 −4 mol m −2 s −1.

Dechlorination of chloroacetanilide herbicides by thiosulfate salts.

Halogenated organic compounds (XOCs) are among the most widely used synthetic chemicals. Many XOCs are recalcitrant to natural degradation and have become prominent environmental contaminants. One group of such XOCs are the heavily used chloroacetanilide herbicides. We have found that chloroacetanilide herbicides are rapidly dechlorinated in water, sand, and soil by thiosulfate salts under ambient conditions. Structural and kinetics analysis suggests that the reaction occurred by S(N)2 nucleophilic substitution, in which the chlorine was replaced by thiosulfate and the herbicide was detoxified. Laboratory studies showed that this reaction could be used for removing residues of chloroacetanilide herbicides in water, soil, and sand. Our findings also suggest that some other XOCs may be subject to this reaction. Because common thiosulfate salts are innocuous products (e.g., fertilizers) and the reaction selectively detoxifies XOCs at low thiosulfate levels, this discovery may lead to a new way for safe removal of certain XOCs from the environment.