Reaction Of Hydrogen Sulfide Research Articles

Geochemical transformations of sulfur and their role in the formation of different types and subtypes of saline lakes in Southeastern Transbaikalia

This study focused on the chemistry and isotopes of sulfur in lakes. The bottom sediments and water columns of lakes were found to contain reduced forms of sulfur, including hydrogen sulfide ions, elemental sulfur, and thiosulfate ions, along with sulfate ions. It was determined that elemental sulfur in lakes is present mainly in the form of suspensions and colloids, and the proportion of elemental sulfur in polysulfides increases with increasing water pH. It was shown that sulfate reduction results in the greatest isotope fractionation, with a light sulfur isotope accumulating in hydrogen sulfide ions and a heavy sulfur isotope accumulating in sulfate ions. It was confirmed that the abiotic reaction of hydrogen sulfide with oxygen yields a mixture of products that are depleted in 34S and enriched in 34S in hydrogen sulfide. In contrast, the microbial oxidation of HS− → S0 yields zerovalent sulfur, which is 2–4‰ heavier than the initial product. It was shown that the loss of sulfate ions due to bacterial reduction is most significant in subtype-I and subtype-III chloride and soda lakes. In contrast, in subtype-II sulfate and soda lakes, an increase in sulfate ions was noted due to the oxidation of hydrogen sulfides in water-bearing rocks and bacterial hydrogen sulfide. This finding indicated that in addition to evaporation, the formation of a particular type and subtype of saline lake involves the processes of aluminosilicate hydrolysis, sulfate reduction and hydrogen sulfide oxidation.

PURIFICATION OF HYDROCARBON NATURAL GASES FROM HYDROGEN SULFIDE IN A TUBULAR TURBULENT APPARATUS

Purification of gases and petroleum products from sulfur compounds has always been one of the main problems of oil and gas processing and gas transportation. In recent decades, this problem has become even more urgent due to the tightening of requirements for the quality of petroleum products and the transition to high requirements for combustible natural gas supplied and transported through main gas pipelines. To ensure standardized indicators for hydrogen sulfide in gas, purification of this component is required. Traditionally, desulphurization of light hydrocarbon raw materials is reduced to removing hydrogen sulfide with amine solutions and removing mercaptans with aqueous-alkaline solutions using absorption equipment. To purify natural petroleum gas from hydrogen sulfide, it seems promising to use direct-flow vortex devices with small dimensions to create the required interfacial surface, as well as low hydraulic resistance. Based on the high rate of reaction of hydrogen sulfide with a hydrogen sulfide absorbent based on formaldehyde, research has been carried out to develop a technology for purifying associated petroleum gas using a tubular turbulent apparatus. By creating a high specific contact surface between the gas phases and the hydrogen sulfide absorber using the proposed technology, high efficiency in purifying associated gas from hydrogen sulfide was achieved under field conditions. Purified associated petroleum gas with a hydrogen sulfide content of 0.003 g/m3 complied with the STO Gazprom standard 089-2010 and the Technical Regulations of the Eurasian Economic Union 046/2018.

Reaction of Hydrogen Sulfide with a Chlorine Atom in the Temperature Range of 273 to 366 K

Reaction of Hydrogen Sulfide with a Chlorine Atom in the Temperature Range of 273 to 366 K

Molecular and optical characterization reveals the preservation and sulfurization of chemically diverse porewater dissolved organic matter in oligohaline and brackish Chesapeake Bay sediments

In this study, we conducted a detailed analysis of porewater downcore chemical properties and porewater dissolved organic matter (PDOM) composition using elemental C, N and S analysis, fluorescence spectroscopy, and ultrahigh resolution mass spectrometry (FT-ICR MS) at two contrasting sites in Chesapeake Bay. The sites, situated in the oligohaline upper bay and in the seasonally hypoxic mesohaline mid bay, receive fundamentally different detrital inputs predominantly from allochthonous and autochthonous sources, respectively. Unsurprisingly, we observed greater molecular oxygenation and degree of aromaticity in downcore PDOM profiles from the upper bay. At the mid bay station, PDOM composition was more indicative of non-aromatic algal-derived material. Unexpectedly, this autochthonous PDOM had lower C:S ratios. Hence, algal-derived organic matter appeared to be readily sulfurized, which was confirmed by quantification of dissolved organic sulfur as well as by qualitative interpretation of FT-ICR MS data. This finding suggests addition reactions of hydrogen sulfide to double bonds in unsaturated, but non-aromatic, organic molecules in autochthonous PDOM. Intriguingly, we also observed increases in humic-like fluorescence and dissolved organic carbon (DOC) concentrations in downcore PDOM profiles from both sites. Given the differences in molecular composition between sites, these results show that humic-like fluorescence can arise from different sources and biogeochemical processes. In the upper bay, we infer that these fluorescence signals reflect solubilization of terrestrially derived organic matter with a high aromatic and polyphenolic composition. By contrast, in the mid bay, these fluorescence peaks correlated negatively with hydrogen sulfide and are more likely linked to bacterial sulfate reduction.

Production and purification of anhydrous sodium sulfide

Anhydrous sodium sulfide (Na2S) is a key component in sodium-sulfur batteries as well as an important chemical reagent. However, anhydrous Na2S is currently prohibitively expensive for applications outside of research labs, and purity is a concern. Herein, we compare the properties of three forms of anhydrous Na2S: (i) commercially supplied, (ii) Na2S produced through dehydration and purification of commercial hydrate flakes (Na2S•xH2O), and (iii) Na2S formed by the reaction of hydrogen sulfide with dissolved sodium alkoxide and recovered through solvent evaporation. Vacuum annealing of low-cost Na2S hydrate at 150°C produced anhydrous Na2S. This dehydrated material retains impurity signatures attributed to polysulfide (Na2S x ) and oxysulfur impurities (SO x ) that were also observed in commercially supplied Na2S. Impurity removal typically requires hydrogen reduction at very high temperature (700–900°C), but it is demonstrated here that this can instead be accomplished at 400°C, preventing auto-oxidation and following kinetics well-described by a shrinking core model. The solution-based approach resulted in the direct synthesis of crystalline Na2S anhydride at low temperatures (100°C) without need for further purification. Both approaches presented herein are inherently scalable with materials costs that are one to two orders of magnitude lower than the current price of anhydrous Na2S.

Ab Initio-Based Global Potential Energy Surface and Reaction Dynamics for H2S + C

Dynamics of the reaction of hydrogen sulfide, H2S(X1A1), with ground state atomic carbon, C(3Pj), was investigated over the interpolated ab initio based potential energy surface using the quasi-classical trajectory (QCT) simulation. The reaction probability and total reactive cross section were calculated at wide range of collision energies from 2.6 kJ mol-1 to 78.8 kJ mol-1. The total rate constant of the reaction was calculated using collision theory. The energy distribution for the formation of main products (HCS/HSC + H) were also investigated. At 44.6 kJ mol-1 collision energy approximately 39.5% and 12% of total available energy release to translational and rotational energy levels of the HCS + H products, respectively, while for HSC + H these values were found to be about 61.6% and 25.7% of total available energy. The rest of total energy deposited in the vibrational modes of the products.

Kinetics of a Heterogeneous Reaction of Hydrogen Sulfide with Iodine Oxide in the Temperature Range of 273 to 368 K

The reaction of radical of iodine oxide (IO) with hydrogen sulfide in the temperature range of 273 to 368 K is studied by the method of resonance fluorescence of iodine atoms. The temperature dependence of the rate constant of this reaction is described by the expression kII(T) = (1.6 ± 0.3) × 10–14exp(1035/T) cm3 molecule–1 s–1. It is proved that these substances react mainly on the wall of the reactor. The possibility is discussed that these substances react in the sea and coastal zones.

Enhancement of Low-Temperature Gas-Sensing Performance Using Substoichiometric WO3-x Modified with CuO.

To verify the effect of oxygen vacancy on gas sensitivity, we have systematically investigated the gas-sensing performance of copper oxide/substoichiometric tungsten oxide (CuO/WO3-x) nanocomposite sensors. Oxygen deficiency in WO3-x facilitates the reaction of hydrogen sulfide (H2S) gas with chemisorbed oxygen species (i.e., O2-, O-, and O2-) at low temperature. The oxygen/sulphur exchange reaction between CuO and H2S in the sensing process can achieve room temperature operation of gas sensors. After the WO3-x nanorods were modified by a low content of CuO nanoparticles (Cu:W = 1:20), the sensors present an n-type sensing behavior. Their best working temperatures drop from 289 °C (or 386 °C) to 99 °C (or 70 °C) at which the responses are improved by 14 to 163 times for different x values. Among them, CuO(L)/W5O14 shows the highest sensitivity of 1575.7 to 10 ppm H2S at 99 °C and 171.5 to 10 ppm H2S at room temperature. Once WO3-x were loaded with a high concentration of CuO nanoparticles (Cu:W = 1:2), they exhibit a p-type behavior, and the optimal working temperatures reduce suddenly to room temperature at which CuO(H)/W18O49 displays the most sensitive response of 7.2 even toward trace amounts of H2S as low as 100 ppb. In addition, p-type CuO weakens the metal-like characteristics of W18O49 and such weakening effect enhances with an increase in the CuO content. Therefore, the sensing performance of the CuO/W18O49 composite is the best among the four CuO/WO3-x sensors. The two designs for low and high Cu/W molar ratios all achieve enhanced room-temperature H2S gas response, with a fast recovery time of ∼60 s under heating pulse, as well as an excellent selectivity, which makes the sensors a promising candidate for practical applications. Moreover, the micro-Raman spectra confirmed CuS formation and the thermal effect on the decomposition of CuS in the sensing process was studied.

Characterization of Polysulfides, Polysulfanes, and Other Unique Species in the Reaction between GSNO and H2S.

Glutathione-based products, GSnX, of the reaction of hydrogen sulfide, H2S, S-nitroso glutathione, and GSNO, at varied stoichiometries have been analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS) and chemical trapping experiments. A wide variety of glutathione-based species with catenated sulfur chains have been identified including sulfanes (GSSnG), sulfides (GSSnH), and sulfenic acids (GSnOH); sulfinic (GSnO2H) and sulfonic (GSnO3H) acids are also seen in reactions exposed to air. The presence of each species of GSnX within the original reaction mixtures was confirmed using Single Ion Chromatograms (SICs), to demonstrate the separation on the LC column, and given approximate quantification by the peak area of the SIC. Further, confirmation for different GSnX families was obtained by trapping with species-specific reagents. Several unique GSnX families have been characterized, including bridging mixed di- and tetra-valent polysulfanes and internal trithionitrates (GSNHSnH) with polysulfane branches. Competitive trapping experiments suggest that the polysulfane chains are formed via the intermediacy of sulfenic acid species, GSSnOH. In the presence of radical trap vinylcyclopropane (VCP) the relative distributions of polysulfane speciation are relatively unaffected, suggesting that radical coupling is not a dominant pathway. Therefore, we suggest polysulfane catenation occurs via reaction of sulfides with sulfenic acids.

High-level theoretical study of the hydrogen abstraction reaction H2S + O2 = SH + HO2 and prediction of the rate constants

Hydrogen abstraction reaction of hydrogen sulfide (H2S) by molecule oxygen (O2) forming hydroperoxyl radical (HO2) and hydrosulfide radical (SH) is very important for both atmospheric and combustion chemistry. This work reports a systematic theoretical study on this reaction using a combination of high-level quantum chemistry methods and chemical kinetic theory. Geometry optimizations for all species are performed at QCISD/cc-pVQZ level of theory. The energies for minima and transition state are computed using both single- and multi-reference ab initio methods. It is found that the transition state of this reaction exhibits significant multi-reference nature based on 〈S2〉 and T1 diagnostic during CCSD(T) calculations. The predicted reaction barrier from high-level multi-reference CASPT2(20e,13o)/aug-cc-pVTZ method is higher than those from CCSD(T) and W1BD methods by 6–7 kcal mol−1. Reaction energy barriers from a series of DFT methods also show large deviations compared with both single- and multi-reference methods. Thermal rate constants are calculated over a temperature range from 300 to 2500 K by employing canonical transition state theory with Eckart tunneling correction and the treatment of torsional mode. This work provides accurate rate constants for this reaction and fundamental benchmark results for H/O/S reaction systems, which is valuable for theoretical chemistry and kinetic modeling of sulfur chemistry.

A theoretical study on the kinetics of multichannel Multiwell reaction of H2S(1A1) with HO2(2A′′)

The mechanism and kinetics of the reaction of hydrogen sulphide (H2S(1A1)) with hydroperoxyl radical (HO2(2A″)) on the lowest doublet potential energy surface have been theoretically studied. The potential energy surface for possible pathways has been investigated by employing Complete Basis Set (CBS), DFT, and CCSD(T) methods. Three possible pathways are suggested for the title reaction. The most probable entrance channel consists of formation of a hydrogen-bonded pre-reaction complex (vdw1) and two energised intermediates. Multichannel RRKM-Steady State Approximation and CVT calculations have been carried out to compute the rate constants over a broad range of temperature from 200 K to 3000 K to cover the atmospheric and combustion conditions and pressure from 0.1 to 2000 Torr. No sign of pressure dependence was observed for the title reaction over the stated range of pressure. We have shown that the major products of the title reaction are H2O2 and SH while at higher temperatures, formation of the other products such as H2O, HOS, HSOH and OH are feasible, too. Our calculated overall rate constant is in agreement with the reported experimental data in the literature.

ACEME: Reducing of CO2 and H2S for biogas upgrading using accelerated mineralization

To reduce carbon dioxide and hydrogen sulfide concentration in simulated biogas, experiments were performed on a laboratory scale. The main goal was to use calcium, lead and zinc from fly ash from waste combustion power plants to form carbonates and sulfides for biogas upgrading within a process water cycle. Thereby, the contact time between the simulated biogas and the ionized process water was limited to less than 1 s. The investigation focused on the influence of hydrogen sulfide partial pressure, reaction time, reaction temperature, and process water volume flows. The experiments were performed with two different ashes.The results show that the kinetics for hydrogen sulfide reactions were better than for carbon dioxide where the mass transfer into the liquid phase slows down the upgrading process. This led to fast reactions for H2S in the initial volume and therefore to a bottleneck for further sequestration. For carbon dioxide the kinetics limit the process in the beginning until all reactants for carbonates and the process water volume flow limit the process also. For the process temperature, slightly better separation efficiencies were realized for carbon dioxide at 40 °C while the effect for hydrogen sulfide separation was contradictory for the used ashes. With higher process water volume flow, best results were achieved and the bottleneck of reactants ratios was compensated. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13144, 2019

The reaction of hydrogen sulfide with disulfides: formation of a stable trisulfide and implications for biological systems.

The signalling associated with hydrogen sulfide (H2 S) remains to be established, and recent studies have alluded to the possibility that H2 S-derived species play important roles. Of particular interest are hydropersulfides (RSSH) and related polysulfides (RSSn R, n>1). This work elucidates the fundamental chemical relationship between these sulfur species as well as examines their biological effects. Using standard analytical techniques (1 H-NMR and MS), the equilibrium reactions between H2 S, disulfides (RSSR), RSSH, dialkyltrisulfides (RSSSR) and thiols (RSH) were examined. Their ability to protect cells from electrophilic and/or oxidative stress was also examined using cell culture. H2 S, RSSR, RSSH, RSSSR and RSH are all in a dynamic equilibrium. In a biological system, these species can exist simultaneously, and thus, it is difficult to discern which species is (are) the biological effector(s). Treatment of cells with the dialkyl trisulfide cysteine trisulfide (Cys-SSS-Cys) resulted in high intracellular levels of hydropersulfides and protection from electrophilic stress. In aqueous systems, the reaction between H2 S and RSSR results in the formation of equilibria whereby H2 S, RSH, RSSR, RSSH and RSSSR are present. In a biological system, any of these species can be responsible for the observed biological activity. These equilibrium species can also be generated via the reaction of RSH with RSSSR. Due to these equilibria, Cys-SSS-Cys can be a method for generating any of the other species. Importantly, HEK293T cells treated with Cys-SSS-Cys results in increased levels of hydropersulfides, allowing examination of the biological effects of RSSH. This article is part of a themed section on Chemical Biology of Reactive Sulfur Species. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.4/issuetoc.

Mechanism of Sulfide Binding by Ferric Hemeproteins

The reaction of hydrogen sulfide (H2S) with hemeproteins is a key physiological reaction; still, its mechanism and implications are not completely understood. In this work, we propose a combination of experimental and theoretical tools to shed light on the reaction in model system microperoxidase 11 (MP11-FeIII) and myoglobin (Mb-FeIII), from the estimation of the intrinsic binding constants of the species H2S and hydrosulfide (HS-), and the computational description of the overall binding process. Our results show that H2S and HS- are the main reactive species in Mb-FeIII and MP11-FeIII, respectively, and that the magnitude of their intrinsic binding constants are similar to most of the binding constants reported so far for hemeproteins systems and model compounds. However, while the binding of HS- to Mb-FeIII was negligible, the binding of H2S to MP11-FeIII was significant, providing a frame for a discriminated analysis of both species and revealing differential mechanistic aspects. A joint inspection of the kinetic data and the free energy profiles of the binding processes suggests that a dissociative mechanism with the release of a coordinated water molecule as rate limiting step is operative in the binding of H2S to Mb-FeIII and that the binding of HS- is prevented in the access to the protein matrix. For the MP11-FeIII case, where no access restrictions for the ligands are present, an associative component in the mechanism seems to be operative. Overall, the results suggest that if accessing the active site then both H2S and HS- are capable of binding a ferric heme moiety.

Hydrogen Sulfide as a Scavenger of Sulfur Atomic Cation.

The well-studied hydrogen sulfide molecule is shown here for the first time to form a S-S bond barrierlessly with sulfur atomic cation to produce stable H2SS+, a compound for which there is nearly no literature data. Previous work has shown that the reaction of hydrogen sulfide with neutral atomic sulfur will likely only take place at high pressures. Conversely, this work shows that hydrogen sulfide will readily bind with atomic sulfur cation first through the 1 4A″ state from association of H2S with S+(4S) and then will relax to the nearly degenerate 1 2A' or 1 2A″ states. S+(4S) + H2S lies 29.5 kcal/mol above the 1 4A″ H2SS+ minimum. The 1 4A″ H2SS+ minimum in the S-S bond is also directly intersected by the doublet potential energy surface. As the S-S bond shortens in the association, the 1 2A' and 1 2A″ states split, falling 33.5 and 26.4 kcal/mol, respectively, below the 1 4A″ state. Hence, this work is opening the door for novel synthesis of S-S bonds or potential removal of the common H2S toxin/pollutant through concatenation and subsequent precipitation.

Syngas clean-up system kinetics investigation

Zinc oxide and hydrogen sulfide reaction was researched experimentally. Dynamic characteristics (solid phase mass change per time, temperature change per time inside the reactor, gas volume flow rate on inlet) were obtained for pure ZnO powder and granular sorbent Katalco 32-4-Johnson & Matthey by thermo-gravimetric analyzer. Pre-exponential factor, energy activation and specific mass flow rate of ZnO were numerically calculated for pure ZnO. Pure ZnO, ZnO2SC, and granular sorbent conversion rates were compared. Thermogravimetric experiments with pure ZnO and with ZnO2SC were simulated in ANSYS Fluent software. Kinetic constants were input parameters for CFD software. Simulation data and experimental results agree well on sorbent conversion diagram.

ALTERED RHYTHMIC SULPHIDE BANDS IN THE WEISSLIEGEND SANDSTONE IN THE RUDNA MINE (FORE-SUDETIC MONOCLINE, POLAND)

Two cross sections of Weissliegend sandstones from the Rudna Mine, containing copper sulphide rhythmic banding, were studied. Analyses were performed using optical polarizing (PLM) and scanning electron (SEM-EDS) microscopy and XRD. Rhythmites have different sulphide compositions and undergone different alterations. In cross section RZA rhythmites are composed of copper sulphides, mainly digenite, and strongly altered to covellite and atacamite by secondary processes. Primary rhythmites were probably formed via reaction between hydrogen sulphide from the overlying shale and copper-bearing solutions in the sandstone. Extensive weathering and mining waters were probably resposible for atacamite formation, although other possibillities are also considered. In cross section RGM rhythmites are composed of Cu–Fe sulphides (bornite and chalcopyrite) and pyrite. This distinct mineralogy may result from a reaction of hydrogen sulphide from the overlying shale with copper- and iron-bearing solutions. Dissolution of pyrite or iron monosulphides present in the sandstone could enrich the solutions in iron. Primary ore mineralization was overlapped by a secondary mineralization of slightly different composition.

Development of a derivatization method for the quantification of hydrogen sulfide and its application in vascular calcification rats.

Hydrogen sulfide (H2S) plays major functional and structural roles in diverse physiological functions and the pathogenesis of a variety of disorders in biological matrices. The significance of H2S has prompted the development of sensitive and selective methods to determine its concentration in biological samples. The fluorescent reagent monobromobimane (MBB) has been widely used to measure various thiol-containing species through alkylation. MBB may prevent the oxidation of sulfide and the reaction of sulfide with several different species (such as superoxide radicals, hydrogen peroxide and peroxynitrite). An isomers of MBB, 3-(bromomethyl)-2, 6, 7-trimethyl-1H, 5H-pyrazolo [1,2-a] pyrazole-1, 5-dione (MMB), is cheaper than MBB and its use in the analysis of H2S has not previously been reported. In the present study, we compared the derivatization reactions of hydrogen sulfide with MMB and MBB and developed a sensitive method to quantify H2S in blood. In our method, H2S was incubated in the dark with excess MMB in 0.1M Tris-HCl buffer (pH 10.1) at 50°C for 120min. 50μL aliquots of the derivatized product were analyzed using HPLC system with gradient elution of 0.1% (v/v) formic acid-acetonitrile. The limit of detection for the derivatized product was 0.03nmol/mL. The derivatization reaction was suitable for detecting low concentrations of H2S. The derivate product is stable over time, permitting batch storage and analysis.

S-Transnitrosation reactions of hydrogen sulfide (H2S/HS−/S2−) with S-nitrosated cysteinyl thiols in phosphate buffer of pH 7.4: Results and review of the literature

Cysteine (CysSH) and its derivatives including N-acetylcysteine (NAC) and glutathione (GSH), and cysteine residues in proteins and enzymes are nitrosated with nitric oxide (NO) reaction products such as N2O3 to form S-nitrosated cysteine thiols (RCysSNO). RCysSNO undergo with cysteine thiols (RCysSH) S-transnitrosation reactions, thereby transferring reversibly their nitrosyl (+NO) group to RCysSH to form RCysSNO. •NO release from RCysSNO and S-transnitrosation are considered the most important features and signalling pathways of RCysSNO. Hydrogen sulfide (H2S: pKa1, 7; HS−: pKa2, 12.9) is an endogenous product of cysteine metabolism. We hypothesized that RCysSNO would also undergo S-transnitrosation reaction with H2S/HS−/S2− to form thionitrite (ONS−), the smallest S-nitrosated thiol. This article describes spectrophotometric and mass spectrometric investigations of S-transnitrosation reactions in phosphate buffered saline (PBS) of pH 7.4 between H2S/HS−/S2− (supplied as Na2S) and S-nitrosoglutathione (GSNO), S-nitroso-l-cysteine (CysSNO), S-nitroso-N-acetyl-l-cysteine (SNAC), and the synthetic S-nitroso-N-acetyl-l-cysteine ethyl ester (SNACET). For comparison, we also investigated the reactions of H2S/HS−/S2− with NO+BF4− and NO2+BF4−, direct ON+ and O2N+ donors, respectively, and assumed formation of ONS− and thionitrate (O2NS−), respectively. Addition of Na2S (at 1 mM) to buffered RCysSNO solutions resulted in decreases of the absorbance at 340 nm and concomitant increases in the absorbance at 410 nm depending upon the nature and concentration of RCysSNO (range, 25–1000 μM). The reactivity order of RCysSNO against H2S/HS−/S2− was: CysSNO > SNACET > GSNO > SNAC. Our spectrophotometric and GC-MS analyses indicate that H2S/HS−/S2− and RCysSNO undergo multiple reactions. Major final reaction products were found to be nitrite and nitrate. ONS− and O2NS− were not detected by GC-MS, suggesting rapid and complete S/O-exchange from water at pH 7.4. GC-MS analyses of ethyl acetate extracts of reaction mixtures suggested formation of tetrasulfur (S4), the precursor of elemental sulfur (S8). The broad absorbance around 410 nm and the turbidity occurred in RCysSNO/Na2S reaction mixtures support formation of polysulfides (polysulfanes) and colloidal sulfur. The reaction of NO+BF4− and NO2+BF4− with H2S/HS−/S2− differed from the S-transnitrosation reactions of RCysSNO, with NO+BF4− being more reactive than NO2+BF4−. In this article, we also briefly review and discuss recent published work dealing with the reaction of H2S/HS−/S2− with low- and high-molecular-mass S-nitrosated thiols. This research area is highly challenging and controversial with respect to the primarily formed reaction products. The synthesis of structurally well-characterized, pure stable-isotope labelled species of putative reaction products, including ONS−, O2NS− and ONSS−, and their use in combination with mass spectrometry coupled to chromatography, e.g. GC-MS and LC-MS/MS, are indispensable in exploring the complex interaction of the two gasotransmitters, H2S and •NO.

A reaction-based and highly selective fluorescent probe for hydrogen sulfide

Based on the thiolysis of 7-nitro-1,2,3-benzoxadiazole (NBD) amine, a novel fluorescent probe for hydrogen sulfide was designed and synthesized, which contains 5 (6)-carboxy-rhodamine as fluorophore and NBD as hydrogen sulfide reaction group. The probe is non-fluorescent, and could selectively detect hydrogen sulfide with a big fluorescence enhancement of 160-fold and a low detection limit of 4.80 × 10−8 mol/L. Furthermore, coupled with its good biocompatibility, the probe has been used for fluorescent bioimaging of H2S in living cells.