Volatile Organic Amines Research Articles

A dual response organogel system based on an iridium complex and a Eu(iii) hybrid for volatile acid and organic amine vapors.

A thiophene-based hybrid organogel system consisting of complex iridium (Ir) and EuCl3·6H2O was designed and synthesized to realize dual responses to volatile acids and organic amine vapors. The photophysical properties and self-assembly of compound 1 and the hybrid organogel were also studied. Compound 1 could gelate some organic solvents and self-assemble into 3D nanofibers in the gels. The stable hybrid organogel 1-Ir-Eu could be obtained after addition of complex Ir and EuCl3·6H2O. FTIR spectral results showed that the hydrogen bond still remained even upon addition of complex Ir, EuCl3·6H2O, NaOH and CF3COOH to organogel 1. Interestingly, the emission properties of the hybrid organogel 1-Ir-Eu could undergo interconversion between cyan light and red light via addition of NaOH and CF3COOH. The emission properties of xerogel film 1-Ir-Eu obtained in the presence of NaOH could also undergo fast and reversible transition in response to volatile acids such as CF3COOH, formic acid, acetic acid, propionic acid and organic amine vapors such as ammonium hydroxide, Et3N, tripropylamine, and ethylenediamine. The emission spectral change of Ir-Eu in the organogel or xerogel in the presence of base and acid demonstrated the formation of a new complex between complex Ir and EuCl3·6H2O. This dual-response process could be repeated many times. Contact angle experiment results further showed the morphology and internal components of the xerogel film surface in the process of response to gaseous CF3COOH and Et3N. This work provides a method for producing multifunctional supramolecular materials for sensing volatile acids and organic amine vapors.

AIE-active molecule-based self-assembled nano-fibrous films for sensitive detection of volatile organic amines

AIE-active molecule-based self-assembled nano-fibrous films were designed and prepared for the sensitive detection of volatile organic amines.

Highly conductive polythiophene films doped with chloroauric acid for dual-mode sensing of volatile organic amines and thiols

Highly conductive polythiophene films with electrical conductivity of 71.7S/cm were prepared by using a facile solution-processing method with HAuCl4 as a dopant. The density of free charge carriers for thus-prepared polythiophene films was estimated to be 4.48×1021/cm3. In addition, upon doping, the color of the polymer films changed significantly with the main absorption peaks bathochromically shifted from the visible to near-infrared region. Interestingly, the polythiophene films could be easily dedoped when exposed to organic amines and thiols. The dual variations of film color and electrical conductivity thus were exploited for the design and fabrication of a logic circuit, in combination with polythiophene films doped by electrochemical oxidation, for selective detection of volatile amines and thiols with a detection limit lower than 1ppm. The results demonstrate the high potential of this solution-doping method in the preparation of highly conducting organic thin films for vapor sensing.

Highly sensitive and selective volatile organic amine (VOA) sensors using mesoporous WO3–SnO2 nanohybrids

Considering the tremendous toxic effect on human well being and environment, the qualitative and quantitative determination of volatile organic amines (VOAs) is of significant importance. In this paper, nanostructures of WO3–SnO2 having large surface area and uniform pore channels were produced using mesoporous silica, SBA-15 as hard template using a nanocasting strategy. Sensors based on mesoporous WO3–SnO2 nanohybrids were fabricated for detection of important biological odor markers including triethylamine, ethylenediamine, ethanolamine, cyclohexylamine gases. The results exhibit that mesoporous WO3–SnO2 are highly sensitive and distinctly selective to triethylamine (TEA). The response (Ra/Rg) of this sensor to 50ppm TEA was 87 with a fast response and recovery times of 6 and 7s respectively at the operating temperature of 220°C. The detection limit can also be as low as 1ppm-level with a response of 3. Besides, the sensor shows excellent response/recovery and stability in the concentrations ranging from 1 to 500ppm. These high sensing performances mainly attribute to the formation of unique heterojunction at the WO3–SnO2 interface and the presence of intrinsic high surface area supported by mesopores arrangement, which collectively offers great variation of resistance in air and TEA molecules (heterojunction) alongside facilitating the faster propagation and adsorption/desorption of TEA molecules across the sensor surface (mesoporous structure). Thus, the nanocasted mesoporous material provides an effective and efficient strategy to design new TEA gas sensors.

Recent progress in thin film fluorescent probe for organic amine vapour

There are great needs for real-time detection of volatile organic amines (VOA) through low-cost detection methods in public health, food safety, and environmental monitoring area. Organic thin-film fluorescent probe (OTFFP) is expected to become a new and efficient means of detecting VOA because of its fast response, high sensitivity, no contamination to the analyte and ease to prepare a portable instrument. Compared with the mature detection methods in solution, research on solid fluorescence sensing has been less studied. In this article, we review recent progress in OTFFP research for VOA vapour. We mainly focus on the new fluorescent sensing mechanisms applied in solid state in recent years and the design principle of probes for different types of organic amines (such as primary amine, secondary amine, tertiary amine and aromatic amine). We also review the material structures of these probes and the strategies to enhance their sensitivity or selectivity.

Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors.

An L-phenylalanine derivative (C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively.

A quartz crystal microbalance modified with carbon nanotubes as a sensor for volatile organic compounds

A piezoelectric quartz crystal microbalance (PQCM) was modified with multi-walled carbon nanotubes (MWCNTs) to develop a chemically based sensor for measurements other than the typical mass change in the quartz crystal. Slight conductivity changes in the carbon nanotubes are amplified to obtain a vibrational frequency signal in the crystal. A commercially available quartz crystal microbalance was modified by replacing its electrode with MWCNTs to obtain a sensor with high sensitivity, selectivity, robustness and stability over time. The modified microbalance was successfully used to determine various types of analytes including volatile organic compounds (VOCs), aldehydes and amines.

Using Black Soldier Fly Larvae for Processing Organic Leachates

A large number of biodegradable byproducts including alcohols, soluble saccharides, volatile organic acids, and amines accumulate in the liquid fraction (leachate) produced as vegetal and food scrap waste decomposes. Untreated leachate, because it is rich in nutrients and organic byproducts, has a high chemical oxygen demand and is normally cleared of soluble organic byproducts by mineralization before its discharge into waterways. Mineralizing leachates using chemical and microbial biotechnologies is, however, a lengthy and costly process. We report here that the larvae of the black soldier fly Hermetia illucens (L.) (Diptera: Stratiomyidae), an insect rich in protein and lipids, and having significant commercial value, while feeding and growing off of compost leachate, lowers its chemical oxygen demand relative to that of leachate unexposed to larvae, neutralizes its acidity, and clears it of volatile organic acids, amines, and alcohols. These observations demonstrate that black soldier fly larvae could be used to help offset the cost and clean up of organic solutes in leachate waste streams while recycling carbon, nitrogen, and phosphate into usable and commercially valuable biomass.

Fast detection of organic amine vapors based on fluorescent nanofibrils fabricated from triphenylamine functionalized β-diketone-boron difluoride

Nanofibrils emitting strong red light have been fabricated from triphenylamine functionalized β-diketone-boron difluoride 1, via a rapid solution dispersion approach. It is found that the nanofibrils based on compound 1 can sense volatile organic amines and pyridine selectively. For example, the fluorescence of the nanofibril-based film can be quenched quickly and significantly upon exposed to the vapors of n-butylamine, dibutylamine, tributylamine, triethylamine, cyclohexylamine, hydrazine, aniline, N,N-dimethylaniline and pyridine instead of other common reagents. Notably, the response time of the nanofibril-based film to aniline is ca. 1.06 s, which is one of the fastest fluorescent responses to aniline. The detection limit of the nanofibril-based film for aniline vapor can reach ca. 100 ppb. We suggest that the high sensitivity and fast response of the sensory nanofibrils towards gaseous amines may come from the high surface-to-volume ratio and large interspace in the nanofibril-based networks, which favor the enhanced adsorption, accumulation and diffusion of gaseous molecules. In addition, the amplified fluorescence quenching induced by the enhanced intermolecular exciton diffusion along the long axis of the 1D nanostructures is another reason for the high performance of the obtained sensory nanomaterial.

Preparation and Application of Multiple‐Component‐Doped Keggin Polyoxometalate Microtubes—Towards a Component‐Tunable Hollow Structure

In this paper, the preparation of ascorbic acid (AA)-doped polyoxometalate (SiW(12)-AA) microtubes is described. The SiW(12)-AA microtubes convert to heteropoly blue microtubes upon exposure to ammonia gas, which is an ammonia-triggered solid-solid redox reaction between AA molecules and polyoxometalates, and can possibly be applied to a chemical sensor for detecting ammonia and volatile organic amines. Furthermore, the SiW(12)-AA microtubes have been applied to the in situ synthesis of Ag nanoparticles (NPs) through the redox reaction between the AA component and Ag(+) ions occurring on the surfaces of the SiW(12)-AA microtubes to give silver NPs immobilized on polyoxometalate microtubes (Ag@SiW(12)).

Selective catalytic formic acid decomposition for hydrogen generation in ionic liquids

Abstract Effect of ionic liquids (ILs) as media for the decomposition of formic acid in the presence of organic amine was investigated, and this activity was observed to be markedly promoted by the addition of ILs, especially for BMImCl. Based on this finding and to avoid volatile organic amine, a series of amine-functionalized ILs were further designed and prepared as both reaction media and co-catalyst for homogeneous decomposition of formic acid. Among the ILs investigated, i-Pr 2NEMImCl-HCOONa system exhibited high activity (TOF > 600 mol/mol/h). This efficient and green method to produce hydrogen by formic acid decomposition has practical potentiality.

On-site monitoring of fish spoilage using vanadium pentoxide xerogel modified interdigitated gold electrodes

The development of a vanadium pentoxide xerogel (VXG)-based sensor for the detection of volatile inorganic (ammonia) and organic (dimethylamine, etc.) amines is described. The xerogel film was deposited on interdigitated gold electrodes by dip-coating using an aqueous solution of VXG. The morphology of the sensing layer, its interaction with ammonia, which was used as a model analyte throughout this work, as well as the regeneration of the surface of the sensor electrodes with vapors of HCl were examined with scanning electron microscopy and FTIR spectroscopy. Signal changes, due to changes of the RC-product of the electrochemical cell (Au-VXG-Au), as a result of its interactions with ammonia vapors, were probed with a portable, homemade charge meter, the Multipulser. Exposing the sensor electrodes to various concentrations of ammonia vapors resulted in proportional changes in the signal output. Finally, the proposed sensors were successfully used for on-site, real-time monitoring of fish spoilage in ambient conditions.

Study of the Current Status and Factors That Influence Indoor Air Pollution in 138 Houses in the Urban Area in Xi'an

Indoor air pollutants were monitored in 138 households in urban Xi'an that were recently decorated, and the concentrations of formaldehyde, total volatile organic compounds (TVOC), amines, benzene, methylbenzol, xylene, and radon were monitored in the bedrooms, sitting rooms, dinning rooms, kitchens, bathrooms, and studies of the houses. The most seriously elevated pollutants were TVOC and formaldehyde, whose rates exceeded standards by 69.8% and 60.8%, respectively. Ammonia was 13.2% above the standard, and xylene was 8.7% above the standard. The level of radon in 100% of the rooms was below the standard. Only for formaldehyde were there statistically significant differences in concentrations in the sitting room, bedroom, and study (P < 0.05). Concentrations of TVOC, amines, and xylene were positively related to the concentration of formaldehyde in the same room. The concentrations of the major pollutants in summer were highest and had a statistically significant difference with those in other seasons. TVOC and formaldehyde were the most serious pollutants indoors after decorating in an urban area of Xi'an. The concentrations of formaldehyde in the sitting rooms were different than in other types of rooms. Formaldehyde can be a representative of the levels of pollutants indoors; rooms with a higher concentration of formaldehyde tend to have higher levels of other pollutants. In addition, pollutants in the decorated rooms have a strong positive dependence on the monitoring seasons. Summer was the peak time of indoor pollutant levels. Households should pay extra attention to ventilation and take other effective measures to avoid health problems caused by indoor air pollutants.

Simple analysis of four bisphosphonates simultaneously by reverse phase liquid chromatography using n-amylamine as volatile ion-pairing agent

Volatile organic amine was used as the mobile phase addictive during the separation of four bisphosphonates (alendronate, pamidronate, zoledronic acid and etidronate). An isocratic liquid chromatography method with evaporative light-scattering detection (ELSD) was developed for these bisphosphonates which are not retained on non-polar column and lack chromophore for detection. The analytes have sufficiently separated from each other on a Phenomenex C 18 column. The effects of mobile phase composition and instrumental parameters of ELSD were studied. This newly developed method enables direct measurement for analysis of bisphosphonates without the need of derivatization. This developed method provides high separation and specificity to bisphosphonate analysis. In quantitative analysis, the method showed satisfactory precision (less than 2.8%) and accuracy (higher than 94.4%), good linearity ( r = 0.9991–0.9997) and sufficient sensitivity (15–18 μg/ml). It can be easily and conveniently adopted for the routine quality control analysis.

Small molecular weight organic amino nitrogen compounds in treated municipal wastewater

Concentrations of organic nitrogen compounds (total Kjeldahl nitrogen, total free amino acids, individual amino acids, and volatile amines) in primary and secondary effluents from municipal waste water treatment plants were measured and compared to concentrations of these compounds in primary and secondary effluents as reported by others. Primary treated municipal waste water effluents contained relatively low concentrations of dissolved free amino acids compared with those found in raw sewage as reported by others. A selective purge-and-trap method for the concentration of volatile amines was adapted to the analysis of waste water. Volatile organic amines, not previously reported in waste waters, were found in concentrations comparable to those of some of the amino acids. Secondary treatment generally reduces the concentrations of these amines below detection limits.

Liquid-vapor distribution of amines and acid ionization constants of their ammonium salts in aqueous systems at high temperature

Ammonia and volatile organic amines are used to treat the water in steam generating systems to afford protection of the steam- and feedwater circuits from corrosion by acidic condensate. The base strength and the volatility of the reagent used are two important parameters that have bearing on its ability to inhibit corrosion; they determine the pH of the solution produced from condensing steam. The distribution of thirteen amines between water and steam in the temperature range 150 to 325°C was studied. The amines were chosen on the basis of their known room-temperature base strength. The acid ionization constant of the ammonium salts of seven of these amines was determined by conductivity measurement in the temperature range 25 to 275°C. Amines with high room-temperature base strength and distribution coefficient in the optimum range were chosen for the high-temperature base strength determination. The results of these studies were used to estimate the effectiveness of these amines in raising the pH of the condensate from steam containing carbon dioxide and acetic acid, to provide the basis for further studies on the corrosion inhibition properties of the amines.

Corrosion during autoclave sterilization. II. Volatile organic amines as corrosion inhibitors.

(1968). Corrosion during autoclave sterilization ii. volatile organic amines as corrosion inhibitors. Acta Odontologica Scandinavica: Vol. 26, No. 1-2, pp. 23-34.