Specific Organic Solvents Research Articles

Occupational exposure to organic solvents and risk of bladder cancer

BackgroundBladder cancer has been linked to several occupations that involve the use of solvents, including those used in the dry-cleaning industry.ObjectivesWe evaluated exposure to solvents and risk of bladder cancer in 1182 incident cases and 1408 controls from a population-based study.MethodsExposure to solvents was quantitatively assessed using a job-exposure matrix (CANJEM). Exposure to benzene, toluene and xylene often co-occur. Therefore, we created two additional sets of metrics for combined benzene, toluene and xylene (BTX) exposure: (1) CANJEM-based BTX metrics and (2) hybrid BTX metrics, using an approach that integrates the CANJEM-based BTX metrics together with lifetime occupational histories and exposure-oriented modules that captured within-job, respondent-specific details about tasks and chemicals. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using logistic regression.ResultsBladder cancer risks were increased among those ever exposed to benzene (OR = 1.63, 95% CI: 1.14–2.32), toluene (OR = 1.60, 95% CI: 1.06–2.43), and xylene (OR = 1.67, 95% CI: 1.13–2.48) individually. We further observed a statistically significant exposure-response relationship for cumulative BTX exposure, with a stronger association using the hybrid BTX metrics (ORQ1vsUnexposed = 1.26, 95% CI: 0.83–1.90; ORQ2vsUnexposed = 1.52, 95% CI: 1.00–2.31; ORQ3vsUnexposed = 1.88, 95% CI: 1.24–2.85; and ORQ4vsUnexposed = 2.23, 95% CI: 1.35–3.69) (p-trend=0.001) than using CANJEM-based metrics (p-trend=0.02).ImpactThere is limited evidence about the role of exposure to specific organic solvents, alone or in combination on the risk of developing bladder cancer. In this study, workers with increasing exposure to benzene, toluene, and xylene as a group (BTX) had a statistically significant exposure-response relationship with bladder cancer. Future evaluation of the carcinogenicity of BTX and other organic solvents, particularly concurrent exposure, on bladder cancer development is needed.

Simple One–Pot Synthesis of Hexakis(2-alkoxy-1,5-phenyleneimine) Macrocycles by Precipitation–Driven Cyclization

Hexakis(2-alkoxy-1,5-phenyleneimine) macrocycles were synthesized using a simple one-pot procedure through precipitation-driven cyclization. The acetal-protected AB–type monomers, 2-alkoxy-5-aminobenzaldehyde diethyl acetals, underwent polycondensation in water or acid-containing tetrahydrofuran. The precipitation–driven cyclization, based on imine dynamic covalent chemistry and π–stacked columnar aggregation, played a decisive role in the one–pot synthesis. The progress of the reaction was analyzed using MALDI–TOF mass spectrometry. The macrocycles with alkoxy chains were soluble in specific organic solvents, such as chloroform, allowing their structures to be analyzed using NMR. The shape-anisotropic, nearly planar, and shape-persistent macrocycles aggregated into columnar assemblies in polymerization solvents, driven by aromatic π-stacking. The octyloxylated macrocycle OcO–Cm6 exhibited an enantiotropic columnar liquid crystal-like mesophase between 165 °C and 197 °C. In the SEM image of (S)-(–)-3,7-dimethyloctyloxylated macrocycle (–)BCO–Cm6, columnar substances with a diameter of 200–300 nm were observed. The polymerization solution for the 2-(2-methoxyethoxy)ethoxy)ethoxylated macrocycle (TEGO–Cm6) gelled, and showed thixotropic properties by forming a hydrogen bond network.

Network topology diversification of porous organic salts.

Hydrogen-bonded organic frameworks (HOFs) are porous organic materials constructed via hydrogen bonds. HOFs have solubility in specific high-polar organic solvents. Therefore, HOFs can be returned to their components and can be reconstructed, which indicates their high recyclability. Network topologies, which are the frameworks of porous structures, control the pore sizes and shapes of HOFs. Therefore, they strongly affect the functions of porous materials. However, hydrogen bonds are usually weak interactions, and the design of the intended network topology in HOFs from their components has been challenging. Porous organic salts (POSs) are an important class of HOFs, are hierarchically constructed via strong charge-assisted hydrogen bonds between sulfonic acids and amines, and therefore are expected to have high designability of the porous structure. However, the network topology of POSs has been limited to only dia-topology. Here, we combined tetrasulfonic acid with the adamantane core (4,4',4'',4'''-(adamantane-1,3,5,7-tetrayl)tetrabenzenesulfonic acid; AdPS) and triphenylmethylamines with modified substituents in para-positions of benzene rings (TPMA-X, X = F, methyl (Me), Cl, Br, I). We changed the steric hindrance between the adamantane and substituents (X) in TPMA-X and obtained not only the common dia-topology for POSs but also rare sod-topology, and lon- and uni-topologies that are formed for the first time in HOFs. Changing template molecules under preparation helped in successfully isolating the porous structures of AdPS/TPMA-Me with dia-, lon-, and sod-topologies which exhibited different gas adsorption properties. Therefore, for the first time, we demonstrated that the steric design of HOF components facilitated the formation, diversification, and control of the network topologies and functions of HOFs.

Experimental and Theoretical Investigations of MAPbX3 -Based Perovskites (X=Cl, Br, I) for Photovoltaic Applications.

This work mainly focuses on synthesizing and evaluating the efficiency of methylammonium lead halide-based perovskite (MAPbX3 ; X=Cl, Br, I) solar cells. We used the colloidal Hot-injection method (HIM) to synthesize MAPbX3 (X=Cl, Br, I) perovskites using the specific precursors and organic solvents under ambient conditions. We studied the structural, morphological and optical properties of MAPbX3 perovskites using XRD, FESEM, TEM, UV-Vis, PL and TRPL (time-resolved photoluminescence) characterization techniques. The particle size and morphology of these perovskites vary with respect to the halide variation. The MAPbI3 perovskite possesses a low band gap and low carrier lifetime but delivers the highest PCE among other halide perovskite samples, making it a promising candidate for solar cell technology. To further enrich the investigations, the conversion efficiency of the MAPbX3 perovskites has been evaluated through extensive device simulations. Here, the optical constants, band gap energy and carrier lifetime of MAPbX3 were used for simulating three different perovskite solar cells, namely I, Cl or Br halide-based perovskite solar cells. MAPbI3 , MAPbBr3 and MAPbCl3 absorber layer-based devices showed ~13.7 %, 6.9 % and 5.0 % conversion efficiency. The correlation between the experimental and SCAPS simulation data for HIM-synthesized MAPBX3 -based perovskites has been reported for the first time.

Application of infrared spectroscopy in combination with chemometric algorithms for determining the presence of styrene-butadiene block copolymer in bitumen products

At present polymer-bitumen binders (PBB), including those containing styrene-butadiene copolymer (SBC), are widely used for improving the performance of asphalt concrete coverings. Qualitative detection of the polymer in the petroleum bitumen composition is a difficult research task owing to the low content of the polymer in the PBB composition. Existing methods for determining the polymer in petroleum bitumen are based on a complex multi-stage extraction or on measuring the specific characteristic viscosity of the polymer in the analyzed PBB. These methods are time-consuming and labor-intensive, and require application of a number of specific organic solvents and reference standards. The present work considers the possibility of applying infrared spectroscopy of disturbed total internal reflection (ATR) with subsequent processing of spectra using chemometric algorithms in the study of PBB containing SBC. Application of the principal component analysis (PCA), as well as one-class classification method, the method of soft independent modeling of class analogy (DD-SIMCA), is illustrated. The use of infrared spectroscopy in combination with chemometric data processing methods greatly simplifies and accelerates the research task of detection SBS in bitumen products. The objective of this work was to solve the classification and identification problem in the course of studying bitumen products, i.e. attributing/non-attributing a bitumen product to PBB with SBS.

Progress in sample pretreatment and detection methods of hexabromocyclododecanes

作为一种常见的溴代阻燃剂,六溴环十二烷(HBCDs)因具备持久性、长距离迁移性、生物蓄积性和高毒性,于2013年被列入《斯德哥尔摩公约》。因此,环境样品中HBCDs污染水平的准确分析和严格控制对完善环境监管长效机制至关重要。然而,实际样品中HBCDs的定性定量分析正面临着基质复杂、目标物含量低等问题。尤其,HBCDs在高温环境及特定有机溶剂中易降解,会产生异构体,提高了分析难度。该综述简述了HBCDs的理化性质、毒性危害和标准限制,重点围绕不同基质中HBCDs的样品前处理和仪器检测两方面进行了总结。论文内容引用2000~2022年的70余篇源于科学引文索引(SCI)与中文核心期刊中的相关论文。总结归纳了固体和液体样品中HBCDs分析的前处理技术,包括索式提取、超声辅助萃取、加速溶剂萃取、超临界流体萃取、液液萃取、分散液液微萃取、固相萃取、分散固相萃取和固相微萃取等,介绍了气相色谱、液相色谱和色谱-质谱联用技术等仪器检测方法在HBCDs分析中的应用。通过综述近期相关研究,侧面表明HBCDs的分析方法研究发展迅速,但也面临一些挑战,如样品前处理步骤繁琐、耗时长、样品量和有机溶剂用量大等问题。最后,对新型样品前处理技术在HBCDs分析中的应用进行了展望。

Accurate identification of radicals by in-situ electron paramagnetic resonance in ultraviolet-based homogenous advanced oxidation processes

Accurate identification of radicals in advanced oxidation processes (AOPs) is important to study the mechanisms on radical production and subsequent oxidation-reduction reaction. The commonly applied radical quenching experiments cannot provide direct evidences on generation and evolution of radicals in AOPs, while electron paramagnetic resonance (EPR) is a cutting-edge technology to identify radicals based on spectral characteristics. However, the complexity of EPR spectrum brings uncertainty and inconsistency to radical identification and mechanism clarification. This work presented a comprehensive study on identification of radicals by in-situ EPR analysis in four typical UV-based homogenous AOPs, including UV/H2O2, UV/peroxodisulfate (and peroxymonosulfate), UV/peracetic acid and UV/IO4− systems. Radical formation mechanism was also clarified based on EPR results. A reliable EPR method using organic solvents was proposed to identify alkoxy and alkyl radicals (CH3C(=O)OO·, CH3C(=O)O· and ·CH3) in UV/PAA system. Two activation pathways for radical production were proposed in UV/IO4− system, in which the produced IO3·, IO4·, ·OH and hydrated electron were precisely detected. It is interesting that addition of specific organic solvents can effectively identify oxygen-center and carbon-center radicals. A key parameter in EPR spectrum for 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin adduct, AH, is ranked as: ·CH3 (23 G) >·OH (15 G) >IO3· (12.9 G) >O2·− (11 G) ≥·OOH (9–11 G) ≥IO4· (9–10 G) ≥SO4·− (9–10 G) >CH3C(=O)OO· (8.5 G) > CH3C(=O)O· (7.5 G). This study will give a systematic method on identification of radicals in AOPs, and shed light on the insightful understanding of radical production mechanism.

Quenching Mechanism of Uranyl(VI) by Chloride and Bromide in Aqueous and Non-Aqueous Solutions

A major hindrance in utilizing uranyl(VI) luminescence as a standard analytical tool, for example, in environmental monitoring or nuclear industries, is quenching by other ions such as halide ions, which are present in many relevant matrices of uranyl(VI) speciation. Here, we demonstrate through a combination of time-resolved laser-induced fluorescence spectroscopy, transient absorption spectroscopy, and quantum chemistry that coordinating solvent molecules play a crucial role in U(VI) halide luminescence quenching. We show that our previously suggested quenching mechanism based on an internal redox reaction of the 1:2-uranyl-halide-complex holds also true for bromide-induced quenching of uranyl(VI). By adopting specific organic solvents, we were able to suppress the separation of the oxidized halide ligand X2·- and the formed uranyl(V) into fully solvated ions, thereby "reigniting" U(VI) luminescence. Time-dependent density functional theory calculations show that quenching occurs through the outer-sphere complex of U(VI) and halide in water, while the ligand-to-metal charge transfer is strongly reduced in acetonitrile.

Occupational exposure to specific organic solvents and risk of subtypes of breast cancer in a large population of Danish women, 1964–2016

ObjectiveTo explore associations between occupational exposure to four specific organic solvents, respectively, and female breast cancer, including subtypes.MethodsUsing the Danish Cancer Registry, we identified 38 375 women under age 70...

Quantitative analysis of peptides and proteins as biomarkers in biological samples by peptide adsorption-controlled (PAC)-LC/MS

In the pharmaceutical industry, various compounds such as antibodies, peptides, oligonucleotides, etc. are being evaluated and developed as new modality drugs as well as small molecule compounds. For the evaluation of these new modalities, the development of analytical methods is essential, but often difficult because the analytical techniques related to these modalities are not as mature as to small molecule compounds. Liquid chromatography/mass spectrometry (LC/MS) is a highly selective and sensitive method with a wide dynamic range, and has become an indispensable instrument for analysis of small molecule compounds. Recently, LC/MS has attracted attention as an alternative to ligand-biding assays for the quantification of peptides and proteins. So far, we have found that the adsorption capacity of a peptide changes abruptly and reversibly around a specific organic solvent content (critical point) in the solution, and based on this property we developed a peptide adsorption-controlled liquid chromatography (PAC-LC) for quantitative peptide analysis. By using PAC-LC, it has become possible to quantify low concentration proteins and peptides in biological samples. In this symposium, I would like to introduce examples of analysis for biomarker proteins and peptides in biological samples using PAC-LC.

An Investigation of the Recovery of Silicon Photovoltaic Cells By Application of an Organic Solvent Method

The issue surrounding the treatment of photovoltaic (PV) waste is one that is gaining traction around the world. The recovery of valuable materials from end-of-life, damaged and out-of-spec PV modules is one PV waste treatment approach that has been investigated. However, this approach usually involves damage to PV cells that could otherwise be reused if extracted undamaged as the lifetime of PV cells is far longer than that of PV modules. Current practice is mainly focused on extracting the elemental constituents such as silver, copper and aluminum as well as recycling of silicon to be used in the fabrication of new PV cells. A method of extracting undamaged PV cells would address PV module waste generation with the added advantage of further reducing the carbon footprint associated with PV module manufacturing. This study will focus on the recovery of undamaged silicon PV cells from end-of-life PV modules by application of an organic solvent method. Specific organic solvents deemed to be appropriate for the recovery process along with operating conditions allowing for the recovery of undamaged PV cells from end-of-life PV modules are investigated. Herein, we compared the proposed PV cell recovery method with current recycling techniques which result in damage to PV cells. Furthermore, we will demonstrate that a comparison based on surface morphology and electrochemical properties between the recovered and virgin PV cells shows that the recovered PV cells could effectively be used in the fabrication of new PV modules.

Efficient blue light-emitting polydibenzofluorenes through the integration of an anthracene unit

Series of light emitting polymers based on dibenzofluorene-acene have been synthesized through aromatic nucleophilic substitution reaction. The polymer displayed strong solubility in specific organic solvents with a polydispersity index of 1.5–2.0 and weight average molecular weight within the range from 25000 to 34000. At 420 nm the highest photoluminescence of the polymer solution was observed. The temperature of the thermal decomposition was determined by TGA and ranged from 300 to 446 °C while the value of Tg was between 120 and 140 °C. Cyclic voltammetry tests of polydibezofluorenes show that the compounds with HOMO and LUMO in the range 2.23–5.26 eV is stable under redox condition. The optical properties of these polydibenzofluorenes showed significant blue emissions in the polymers obtained.

Mediator Catalyst for Lithium Fluoride Decomposition for Lithium Recovery

A catalyst to electrochemically decompose lithium fluoride (LiF), which is abound in the electrode of the spent LiBs, was studied to develop a Li reproduction technology. Since the oxidizing activity of halogen I₂, Br₂, Cl₂, or F₂, increases, the reaction I₂ + 2LiF → F₂ + 2LiI cannot proceed. We examined the catalytic activity of interhalogens such as iodine monobromide (IBr) and iodine chloride (ICl) for LiF decomposition in specific organic solvents. We observed the chemical decomposition of LiF in IBr and ICl dimethyl sulfoxide (DMSO) solutions. This decomposition was induced by an increase in solution acidity, accompanied by a large deviation in the electric charge between two halogen elements due to the complex formation of interhalogen with DMSO. A double-chamber-type cell for Li recovery from LiF was constructed by combining this LiF decomposition behavior with redox coupling of IBr or ICl operated by electrical charging. The cell was first demonstrated to be chargeable due to the continuous decomposition of LiF.

Depolymerization of Lignin to Produce Monophenols and Oligomers Using a Novel Ni/Ce-CNT Catalyst

A novel composite catalyst consisting of nickel, cerium, and carbon nanotube (CNT) was developed for native lignin and industrial lignin depolymerization. It was found that Ni and Ce had synergistic effects on the depolymerization. Native lignin was depolymerized to monophenols with a yield of 21.4% at 300 °C for 2 h under 2 MPa hydrogen pressure with serious coke formation. A milder condition set at 280 °C for 2 h under 2 MPa hydrogen pressure provided a monophenols yield of 13.5% with 78.6% lignin removal, but much less coke formation and better catalyst reusability. Even after running the trial four times, the catalyst presented high efficiency. Industrial lignin was depolymerized to oligomers, which are a series of aromatic micromolecules that could be extracted by specific organic solvents such as ethyl acetate. Those oligomers could be used as high calorific value bio-oil. After being depolymerized at 260 °C for 1 h under 2 MPa hydrogen pressure, the yields of oligomers were 56.0% and 11.6% extracted by ethyl acetate (EA) and petroleum ether (PE), respectively. After recycling four times, the catalyst still exhibited high activity. It was clear that the Ni/Ce-CNT was an effective catalyst in lignin depolymerization.

Retarded evaporation-induced synthesis of lamellar block copolymer supramolecules for solvatochromic sensing

The responses of conventional solvatochromic sensors to stimuli are usually performed by generating changes in absorption and emission bands based on the polarity of solvents. However, there still remains a high risk of the overlapped bands for the solvents with similar polarities, resulting in a tough realization of the visual colorimetric differentiation. Here, we develop an innovative solvatochromic sensor in the form of film by self-assembly of block copolymer supramolecules. The produced sensor consists of alternating layers of two phases, in which one is polystyrene (PS) and the other is the combination of poly (4-vinylpyridine) (P4VP) and polydiacetylene (PDA). Owing to the fact that PDA is embedded into P4VP, the inherent protection of PDA by block copolymers is thus guaranteed in such lamellar structures. The specific organic solvents with a strong affinity to PS could merely penetrate into the supramolecular lamellae followed by interacting with thus-exposed PDA, leading to the realization of solvatochromism. By incorporating the heating-induced blue-to-red color transition (thermochromism) with solvatochromism of the sensor, a straightforward technique to realize the nonvisualization of an imprint followed by its revisualization is developed.

A trichromatic MOF composite for multidimensional ratiometric luminescent sensing.

Low-cost, high-performance luminescent probes with wide application potential have been actively pursued. Conventional luminescent probes, which rely on single or dual emissions responsive to analyte molecules, demonstrate limited sensitivity and selectivity because the single emissions can be easily affected by many non-analyte factors, while the dual emissions can only offer single-ratiometric luminescent sensing. Here we report a white-light-emitting trichromatic MOF composite (W2) as the first multidimensional ratiometric luminescent probe. It is facilely synthesized by simultaneously incorporating red- and green-emitting iridium and ruthenium complex cations as encapsulated luminescent modules (ELMs) into a porous blue-emitting MOF via ion exchange. Specific volatile organic solvents (VOSs) can cause VOS-dependent changes to the MOF-to-ELM energy transfer efficiencies in W2, while nitroaromatic (NAC) vapors intriguingly and unprecedentedly quench the three emissions at different rates, both of which enable visible luminescent sensing. Each VOS can be correlated to a unique combination of the two MOF-to-ELM ratios of emission-peak heights, enabling a two-dimensional (2D) code recognition. Furthermore, the time-dependent evolution of the two ratios upon exposure to selective NAC vapors can be mapped out, achieving the first 3D code recognition. Both the synthetic and sensing strategies can be further implemented to develop low-cost and effective luminescent probes.

Organic Electrosynthesis: From Laboratorial Practice to Industrial Applications

Organic electrosynthesis has received great attention as a powerful green tool for synthesis, affording less waste production, less chemicals spent, and often fewer reaction steps than conventional methods. Functional group interconversion and C–C bond generation by imposition of a proper electrode potential is what lies behind organic electrosynthesis processes. Paired electrochemical reactions, indirect electrosynthesis, electrochemical microreactors, and the use of ionic liquids are some of the highlighted means that contribute to optimization of the overall process. Necessity to use specific organic solvents combined with supporting electrolytes is one of the main limitations to be overcome to make the electrochemical process more economically feasible when compared to nonelectrochemical processes. Numerous examples from the bench scale to industrial routes such as adiponitrile, substituted benzaldehydes, anthraquinone, fluorinated products, and succinic acid production are well described throughout t...

New non-traditional organogelator of β-diketone-boron difluoride complexes with terminal tetraphenylethene: Self-assembling and fluorescent sensory properties towards amines

New β-diketone-boron difluoride complexes functionalized with tetraphenylethene (TPEB, DTPEB and TTPEB) which exhibit AIE (aggregation-induced emission) properties have been synthesized. It was found that only boomerang-shaped DTPEB without any traditional gelation groups could form organogel in specific organic solvents. It gave strong orange red fluorescence in organogel as well as in xerogel-based film although it was non-emissive in solution. It is interesting that the emission of DTPEB in xerogel-based film could be quenched significantly upon exposure to triethylamine (TEA) vapour, and the detection limit was as low as ca. 0.1 ppb. This work provides a strategy for the synthesis of a new rigid non-traditional π-gelator via the construction of a boomerang-shaped π-conjugated skeleton. In addition, the gelation of the π-gelators with AIE ability is a facile method for the fabrication of luminescent organic nanomaterials.

Preparation and characterization of a stable nano-sized Zn x Co1–x Al2O4 ink for glass decoration by ink-jet printing

A stable inorganic glass ink was prepared by mechanically grinding a mixture of a blue pigment (Zn x Co1–x Al2O4) and low-melting-point glass powders in a specific organic solvent, which possesses a lower annealing temperature compared with ceramic ink. The Zn x Co1–x Al2O4 based pigment was synthesized by solid-state reaction and the best sintering temperature should be at 1300°C or above according to the observation of XRD. Zn x Co1–x Al2O4 shows blue color both in a powder form and coating. The average particle size of pigments and glass powders mixture decreases with the increase of glass powders and milling time. SEM cross-sectional images of annealed coating samples illustrate that the pigments are well dispersed in the ink layer and the glass adhesive binds well on the surface of glass plate, enhancing the mechanical strength of the ink layer. All the obtained results collectively revealed that the prepared nano-sized Zn x Co1–x Al2O4 ink can be applied in glass decoration.

Eugenol Nanoemulsion Stabilized with Zein and Sodium Caseinate by Self-Assembly.

Eugenol-loaded nanoemulsion by zein and sodium caseinate (NaCas) was prepared without using specific equipment or organic solvents. The deprotonated eugenol in hot alkaline was added to NaCas/zein mixtures with different mass ratios at pH 11.5 and then neutralized to pH 7.0. The nanoemulsions showed a well-defined diameter (around 109-139 nm) and a negative surface potential (from -28.5 to -35.8 mV) with spherical morphology. The entrapment efficiency (EE) of 1% (v/v) eugenol reached 84.24% by 2% (m/v) NaCas/zein at a mass ratio of 1:1. This formulation also showed the narrowest size distribution and extraordinary stability during ambient storage (22 °C) up to 30 days and retained good redispersibility after spray- or freeze-drying. The current study showed a promising clean and low-cost strategy to deliver lipophilic compounds containing the hydroxyl group.