Hydrogen Sulfide In Aqueous Solutions Research Articles

Simple turn-on fluorescent probe for ultrafast and highly selective detection of hydrogen sulfide in aqueous solutions

5H-Benzimidazo[1,2-c]quinazoline-6-thione (BI–QT), was synthesized as a benzimidazole-based probe to detect H2S. BI–QT exhibits a fluorescent “turn-on” response in DMSO/H2O (9:1, HEPES 10 mM, pH 7.4) upon the addition of H2S. The BI–QT probe can determine micromolar (0–600 µM) H2S concentrations in aqueous systems, with a detection limit of 1.12 µM. Interestingly, BI–QT exhibited an ultrafast response to H2S, with maximum intensity achieved almost instantly when exposed to H2S. BI–QT is largely unaffected by pH and responds reliably over the wide 4–11 pH range, which highlights its applicability to various physiological scenarios. UV–vis, fluorescence, and 1H NMR spectroscopic analyses investigated the sensing mechanism. The practicality of the probe was demonstrated using water samples and living cells.

Significance of nucleophilic substitution for ultraviolet dechlorination of pentachlorophenol in the presence of hydrogen sulfide in aqueous solution

Pentachlorophenol (PCP), a highly toxic and persistent agrochemical, is urgent to be dechlorinated for the disintoxication and degradation. Thus, this study aimed to investigate the dechlorination of PCP through ultraviolet (UV) photolysis in the presence of hydrogen sulfide (H2S) in the water, using density functional theory calculations. The theoretical results suggest that 78.2 and 87.6 kcal·mol−1 were required for the dechlorination of PCP and pentachlorophenolate (PCP−) by the homolysis of C-Cl bonds under UV irradiation. The UV photolysis of PCP− could eject hydrated electron (eaq−) and pentachlorophenoxyl radical (PR) in the water. The absorption of eaq− by PCP− enhanced the dechlorination by releasing Cl−. Additionally, the dechlorination could also occur through the nucleophilic reactions of OH−, HS− and S2− with PR, which might be responsible for the enhancement of dechlorination from pH 6.2 to 7.7, and their respective forward energy barriers were 0.5, 6.6 and 21.7 kcal·mol−1 at the para-position. Furthermore, the dechlorination of major quinoid metabolite of PCP (tetrachloro-p-benzoquinone) and its monohydroxylated product under the UV irradiation was facilitated by the nucleophilic attacks on the first triplet states, with the forward energy barriers of 20.4 and 21.7 kcal·mol−1, respectively. Based on the findings in this work, the nucleophilicity of additives may play a dominant role in the dechlorination of PCP, and the combination of H2S and PCP may be helpful for not only the dechlorination of PCP but also the elimination of H2S.

Functionalized organic–inorganic hybrid composites used as colorimetric chemosensors for hydrogen sulfide detection

AbstractDetection of trace‐level hydrogen sulfide (H2S) gas is of great importance both in industrial production and disease diagnosis. In this article, two simple but smart colorimetric chemosensors for H2S detection were designed based upon the principle of colorimetric reaction. Ag NPs, as the main detection agent was loaded onto the primary carrier, silica sulfonic acid. Thus, a silver‐modified silica sulfonic acid (Ag‐SSA) was prepared successfully. Then the Ag‐SSA was integrated with two kinds of secondary substrate materials. One is the cotton‐woven textile and the other one is polyvinyl alcohol (PVA) nanofibrous membrane. Finally, two functionalized organic–inorganic hybrid composite systems for H2S detection were formed. Both of them were able to exhibit a rapid visual color change in response to H2S. Ag‐SSA/cotton textile was tested in the aqueous state and the limit of detection (LOD) of H2S solution was around 10−6 mol/L. For the Ag‐SSA/PVA nanofibers membrane detected in the atmospheric condition, the LOD of H2S gas reached 6.5 ppm. This research has been successfully demonstrated for the application in sensitive and selective detection of hydrogen sulfide in aqueous solution and gaseous state.

Surface functionalization of mesoporous silica nanoparticles with pyronine derivative for selective detection of hydrogen sulfide in aqueous solution

The selective detection of hydrogen sulfide (H2S) in aqueous solution has drawn increasing attention over the past decade. Although many fluorescent chemosensors in homogeneous solutions have been developed, the creation of rapid, highly sensitive and selective fluorescent nanoparticle sensors for detection of H2S are still less reported. In the present work, a novel organic-inorganic composite fluorescent sensor, M-SiO2@PYR, was synthesized by covalent coupling pyronine (PYR) on the solid surface of mesoporous silica nanoparticles. The obtained mesoporous nanoparticles were characterized by TEM and BET measurements. The chemical immobilization of organic fluorophores on the silica nanoparticles were analyzed by FT-IR, XPS, TGA, and solid state NMR methods. The fluorescent mesoporous nanoparticle sensor, M-SiO2@PYR, was found to show sensitive and selective quenching responses toward H2S in aqueous solution compared to a series of competitive analytes. The nanoparticle sensor also displayed a low detection limit of 103.6 nM to H2S, illustrating a high sensitivity. Moreover, the detection of H2S could be also realized in biological fluids like serum or urine. The present work provides a novel way to prepare fluorescent sensor for detecting biothiols in aqueous solution, which may be further used to develop discriminative sensor for multiple biothiols by modulating surface modification.

Eu3+/TFA Functionalized MOF as Luminescent Enhancement Platform: A Ratiometric Luminescent Sensor for Hydrogen Sulfide in Aqueous Solution

In this work, a facile and fast luminescence sensing platform for the ratiometric detection of hydrogen sulfide (H2S/HS−) has been constructed by encapsulating the Eu3+/β-diketone chromophore into the host framework of MIL-140 (Eu3+/TFA@MIL-140C, TFA = 1,1,1-Trifluoro-2,4-pentanedione). It is well known that the energy transfer from the host framework or/and TFA to the Eu3+ ions can be disturbed easily by some metal ions, such as Cu2+ ions. Therefore, the ratiometric sensor was constituted with the Eu3+/β-diketone moiety as the response signal and the host framework moiety as the reference signal. Furthermore, on the basis of the hard–soft acid–base theory, the Cu2+ ions could be rapidly caught by HS−, profiting from the low solubility of CuS, realizing the real-time detection by luminescence color change. This sensor shows remarkable property on the detection of H2S (HS− in water solution) with low limit of detection (LOD = 7.43 μM) and short response time (< 0.5 min). The good linearity between luminescent intensity and concentration makes the luminescent ratio meter feasible.

Colloidal and Deposited Products of the Interaction of Tetrachloroauric Acid with Hydrogen Selenide and Hydrogen Sulfide in Aqueous Solutions

The reactions of aqueous gold complexes with H2Se and H2S are important for transportation and deposition of gold in nature and for synthesis of AuSe-based nanomaterials but are scantily understood. Here, we explored species formed at different proportions of HAuCl4, H2Se and H2S at room temperature using in situ UV-vis spectroscopy, dynamic light scattering (DLS), zeta-potential measurement and ex situ Transmission electron microscopy (TEM), electron diffraction, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Metal gold colloids arose at the molar ratios H2Se(H2S)/HAuCl4 less than 2. At higher ratios, pre-nucleation “dense liquid” species having the hydrodynamic diameter of 20–40 nm, zeta potential −40 mV to −50 mV, and the indirect band gap less than 1 eV derived from the UV-vis spectra grow into submicrometer droplets over several hours, followed by fractional nucleation in the interior and coagulation of disordered gold chalcogenide. XPS found only one Au+ site (Au 4f7/2 at 85.4 eV) in deposited AuSe, surface layers of which partially decomposed yielding Au0 nanoparticles capped with elemental selenium. The liquid species became less dense, the gap approached 2 eV, and gold chalcogenide destabilized towards the decomposition with increasing H2S content. Therefore, the reactions proceed via the non-classical mechanism involving “dense droplets” of supersaturated solution and produce AuSe1−xSx/Au nanocomposites.

Measuring and correlating solubility of hydrogen sulfide in aqueous solution of 2-((2 aminoethyl)amino)ethanol

The solubility of hydrogen sulfide (H2S) in aqueous solution of 2-((2-aminoethyl)amino)ethanol (AEEA) at low and medium pressures was determined for two different concentrations (i.e. 10 and 30 wt%). The experimental total pressure varied from (9.5 to 1594) kPa and the experimental temperature was set to (313.2, 328.2, 343.2 and 358.2) K. The experimental data are presented as the total pressure against acid gas loading (mole H2S per mole of AEEA). The Deshmukh-Mather model and Peng-Robinson equation of state were used for the liquid and vapour phase, respectively, to correlate the solubility of H2S in aqueous solutions of AEEA. The average absolute deviation percent (AAD%) in calculating the total pressure as a function of H2S loading obtained 5.0% for (AEEA– H2O–H2S) ternary system at the four values of temperature. The enthalpy change of the absorption of H2S in the 10 and 30 wt% aqueous solution of AEEA was also estimated with the tuned model.

A sensor system based on a luminescent protein complex in a biopolymer matrix for detecting small concentrations of hydrogen sulfide in aqueous solutions

We have studied the properties of luminescent protein complexes based on myoglobin with covalently bound CY3 luminophore, which were incorporated into polysaccharide agarose films, as potential elements sensitive to hydrogen sulfide (H2S) in aqueous solutions. The presence of this analyte changes the absorption spectrum of myoglobin, which influences the efficiency of luminophore excitation while having almost no effect on its emission spectrum. This effect shows that a luminescent sensor system with the optical response determined by analyte-induced changes in the efficiency of luminescence excitation in the sensitive element can be created. For the system studied, the limit of detection of H2S dissolved in water amounted to 100 pM.

Sensitive detection of sulfide based on the self-assembly of fluorescent silver nanoclusters on the surface of silica nanospheres

Hydrogen sulfide is a toxic and flammable gaseous pollutant often emitted to air as a by-product of water supply, chemical, petroleum and coal industries. It can be transferred into sulfur dioxide in the air under some meteorologic conditions. Herein, we report a novel ratiometric fluorescence method for hydrogen sulfide based on silver nanoclusters and quantum dots. The silver nanoclusters have been self-assemblied onto the surface of silica spheres, which are embedded with red fluorescent quantum dots, to form a dual-emissive nanohybrid. Such dual-emissive nanohybrid has been applied for hydrogen sulfide detection on the basis of the interfacial interaction between silver nanoclusters and sulfide ions. The blue-emission of Ag NCs is specifically prone to hydrogen sulfide due to surface binding and etching, but the red-emission of QDs within the silica nanospheres is inert against hydrogen sulfide. The different response of the two components to hydrogen sulfide results in fluorescence color variation from violet to red when the blue fluorescence is gradually quenched. This nanohybrid has been successfully demonstrated for the application in sensitive and selective detection of hydrogen sulfide in aqueous solution and gaseous state.

High sensitive luminescence metal-organic framework sensor for hydrogen sulfide in aqueous solution: A trial of novel turn-on mechanism

Metal-organic framework (MOF) is a class of crystalline porous solid materials which could be designed as sensors for bioactive molecules. In this study, we illustrated a novel turn-on mechanism based on collapse of MOF structure for luminescence MOF sensors. Taking H2S as an analyte, we validated our mechanism using a specially selected MOF material FeIII-MIL-88-NH2 for H2S sensing. The detection limit towards H2S is about 10μM, which is lower than the reported MOF sensors for H2S designing with other turn-on mechanism.

Solubility of hydrogen sulfide in aqueous solutions of N-methyldiethanolamine at high pressures

A static-analytic method was used to measure the H2S solubility in 50wt% MDEA and in presence of methane as a makeup gas. The solubility was measured at 7000kPa total pressure, and at 50 and 70°C, for H2S partial pressures from 31 to 974kPa. Measurements were also performed at 1500kPa total pressure and 50°C for H2S partial pressure span of 53–386kPa. The measured data were compared to predictions using the Extended UNIQUAC model. The experimental data showed that the total pressure has a significant effect on H2S solubility in aqueous MDEA. The observed effect is shown to be dominated by the non-ideality of the gas, and it could be predicted by the pressure effect on the fugacity coefficient of H2S in the gas phase. The experimental data from this work are compared and shown to be consistent with earlier published data.

A turn-on fluorescent probe for detection of hydrogen sulfide in aqueous solution and living cells

We report the design and synthesis of a turn-on fluorescence probe FD-NO2 for H2S, utilizing H2S selective reduction of the nitro group. FD-NO2 displays good water solubility, negligible background fluorescence, high sensitivity, and high selectivity for H2S over other anions, reactive sulfur, oxygen, and nitrogen species. Further confocal imaging experiments demonstrate that FD-NO2 is capable of detecting H2S in living cells.

A visible light excitable colorimetric and fluorescent ESIPT probe for rapid and selective detection of hydrogen sulfide

In this paper, a visible light excitable ESIPT probe was developed, which was found to be a very promising colorimetric and fluorescent sensor for rapid and selective detection of hydrogen sulfide in aqueous solution. The sensing mechanism and the application of this probe for hydrogen sulfide detection in biological serum and in simulated wastewater samples were investigated.

An “off–on–off” fluorescent probe for the sequential detection of Zn2+ and hydrogen sulfide in aqueous solution

The fluorescent chemosensor L1 has been synthesized for the sequential detection of Zn2+ and hydrogen sulfide.

A quinoline group modified Fe3O4@SiO2 nanoparticles for sequential detection of Zn2+ and hydrogen sulfide in aqueous solution and its logic behavior

A highly selective and sensitive method for recognition of Zn2+ and hydrogen sulfide (H2S) in aqueous solution has been developed by using a quinoline fluorescent sensor functionalized magnetic silica nanoparticles (R1). The chemosensor R1 shows excellent fluorescence sensitivity and selectivity toward Zn2+ and H2S in aqueous media, and displays off–on–off type fluorescence change with alternately adding Zn2+ and H2S to the media along with reversible association–dissociation of the complex. Furthermore, the magnetic nanocomposites can be easily separated from solutions by adding an external magnetic field. Finally, using Zn2+ and H2S as inputs and the fluorescence intensity as output, an INHIBIT logic gate can be constructed at the nanoscale level.

活性炭による溶存硫化水素の酸化と保持

活性炭を用いた溶存硫化物の酸化処理促進技術は，酸化処理後の硫黄形態やその存在比，および酸素消費量について，まだ十分に明らかにされていない。そこで，溶存硫化物の酸化前後の形態と酸素消費量を明らかにするために，バイアル瓶を用いたバッチ式の酸化処理実験を行った。その結果，活性炭の触媒作用によって硫化水素イオンは，硫酸イオン，チオ硫酸イオンに酸化されて溶存していることが確認できた。次に，X線光電子分光分析装置を用いて，活性炭表面にある元素とその電子状態を分析した結果，活性炭に保持された硫黄成分は，元素状硫黄であることが示唆された。また，酸化処理前後の硫黄と酸素の化学量論について計算した結果，それぞれ84％と82％の物質収支を推定することが出来た。さらに，酸化後の硫黄成分の生物毒性について調べた結果，硫化水素イオンは活性炭を用いた酸化により，毒性の低い酸化物になっていることを確認した。

Solubility of Hydrogen Sulfide in Aqueous Solutions of N-Methyldiethanolamine and Piperazine

The solubility of hydrogen sulfide in an aqueous mixture of 2,2'-methyliminodiethanol (N-methyldiethanolamine, [CAS 105-59-9], MDEA) and 1,4-diazacyclohexane (piperazine, [CAS 110-85-0], PIPH 2 ) was measured over a wide range of gas-loadings (stoichiometric molar ratios of hydrogen sulfide to (MDEA + PIPH 2 ) between about 0.014 and 1.67) at three temperatures (about 313 K, 353 K, and 393 K) by headspace gas chromatography as well as by a synthetic gas solubility method. The molality of MDEA in the aqueous mixture was about 4.5 mol·(kg water) ―1 and that of PIPH 2 about 1.6 mol·(kg water) ―1 . The headspace gas chromatography technique was applied in the low pressure range (partial pressure of H 2 S between 0.64 and 125.7 kPa, stoichiometric molar ratio of H 2 S to (MDEA + PIPH 2 ) between about 0.014 and 0.73). The synthetic method was applied in the high pressure range (total pressure between 0.2 and 5.5 MPa, stoichiometric molar ratio of H 2 S to (MDEA + PIPH 2 ) between about about 0.51 and 1.67). The new experimental results are compared to prediction results from a thermodynamic model that was parametrized using only experimental results for the solubility of H 2 S data in the aqueous solution of the single amines in the high pressure range.

A highly selective fluorescent probe for fast detection of hydrogen sulfide in aqueous solution and living cells

A new ratiometric fluorescence probe E1 based on an excited-state intramolecular proton transfer (ESIPT) mechanism for detection of hydrogen sulfide (H(2)S) is reported. E1 responds to H(2)S quickly and showed a 30-fold fluorescence enhancement in 2 minutes. Moreover, E1 can detect H(2)S quantitatively with a detection limit as low as 0.12 μM in aqueous solution. Its potential for biological applications was confirmed by employing it for fluorescence imaging of H(2)S in living cells.

The reduction of selenium(IV) by hydrogen sulfide in aqueous solutions

The rates for the reduction of Se(IV) by sulfides were measured in NaCl solutions as a function of pH (2–10), temperature (10–40°C) and ionic strength (I=0.01–1M). The pseudo first-order rate constant (logk1) showed a complex dependence on pH with values decreasing from pH 2 to a minimum at pH 4.5, then increasing from pH 5.5 to a maximum near pH 8 and decreasing again at pH higher than 8. The values of the overall kinetic constant (k) calculated from the values of k1/[H2S]T can be determined from equations: logk=-0.15pH-1355.5/T+0.44I0.5+7.74 for the pH range 2–4.5 (σ=±0.16), logk=0.28pH-1090.9/T+0.60I0.5+4.68 for the pH range 5.5–7.6 (σ=±0.10) and logk=-0.50pH-1572.1/T+0.45I0.5+12.67 for the pH range 7.7–10 (σ=±0.05), from 10 to 40°C and from 0.01 to 1M ionic strength. The effect of pH and ionic strength on the reaction suggests that the reactions in natural waters are due to the following interactions: H2SeO3+H2S↔productsHSeO3-+H2S↔productsHSeO3-+HS-↔products while under strong alkaline conditions (pH>9) a fourth contribution by SeO32-+HS-↔products is also possible. The overall rate expression over the entire pH range investigated can be determined from (H2A=H2SeO3; HA=HSeO3−; A=SeO32−) k=(kH2S-H2A[H+]3+kH2S-HAKHA[H+]2+kHS-HAKHAK1s[H+]+kHS-AKHAKAK1s)/{([H+]2+KHA[H+]+KAKHA)([H+]+K1s)} where kH2S-H2A=2409±566M-1min-1, kH2S-HA=464±233M-1min-1, kHS-HA=4190±573M−1min−1 and kHS-A=650±382M−1min−1 and KHA, KA and K1s are the dissociation constants of selenous acid and hydrogen sulfide. Kinetic runs in natural freshwater samples and natural seawater have confirmed results obtained in simple NaCl solutions suggesting that this reaction may play an important role under anoxic and hypoxic conditions. Sulfide concentrations under these conditions may range from micromolar to millimolar level and Se(IV) half times are in the order of a few hours to minutes, respectively.

Solubility of Hydrogen Sulfide in Aqueous Solutions of Piperazine in the Low Gas-Loading Region

The solubility of hydrogen sulfide in 2 m (about 0.146 mass fraction) aqueous solutions of 1,4-diazacyclohexane (piperazine, PIPH2) was measured at low gas loadings (at stochiometric molar ratios of hydrogen sulfide to PIPH2 between about 0.14 and 1.04) and low partial pressures of hydrogen sulfide (from about (1.3 to 98.7) kPa) at (313.5 and 392.2) K by headspace gas chromatography. The new experimental results are a supplement to previously published data in the high gas-loading region. The new experimental data are compared to prediction results from a thermodynamic model that was based only on gas solubility data in the high gas-loading area. That thermodynamic model for describing the vapor−liquid equilibrium uses Pitzer’s molality-based equation for the excess Gibbs energy of the aqueous solution. The average relative deviation between the new experimental results and the predictions for the partial pressure of hydrogen sulfide amounts to 10 %.