Gas Chromatography-mass Spectrometry Results Research Articles

Pyrolysis behaviour and synergistic effect in co-pyrolysis of wheat straw and polyethylene terephthalate: a study on product distribution and oil characterization

Renewable lignocellulosic biomass is a favourable energy resource since its co-pyrolysis with hydrogen-rich plastics can produce high-yield and high-quality biofuel. In contrast to earlier co-pyrolysis research that concentrated on increasing product yield, this study comprehends the synergistic effects of two distinct feedstocks that were not considered earlier. This work focuses on co-pyrolyzing wheat straw (WS) with non-reusable polyethylene terephthalate (PET) for the production of pyrolysis oil. WS and PET were blended in different ratios (100/0, 80/20, 60/40, 40/60, 20/80, and 0/100), and pyrolysis experiments were conducted in a fixed-bed reactor under different temperatures to assess their synergistic effect on oil yield. Synergy rates of up to 7.78% were achieved on yield for the blends of plastic and biomass at a temperature of 500 ºC. In comparison to individual biomass or plastics, co-pyrolyzing PET-biomass blends demonstrated good process interaction and promoted the yields of value-added products. The heating value of the pyrolysis oils was in the range of 16.45–28.64 MJ/kg, which depends on the amount of plastic present in the feedstock. The physical analysis of the oils shows that they can be used for heat production by direct combustion in boilers or furnaces. The correlation between WS and PET was validated with the aid of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC-MS) analysis. The GC-MS result demonstrated the presence of different compounds such as O-H compounds, esters, carbonyl group elements, acids, hydrocarbons, aromatics, and nitrogenated compounds in the pyrolysis oil, which differed based on the proportions of PET in the feedstock. The increased hydrocarbon and reduced oxygen percentages in the pyrolysis oil were implicitly caused by enhanced hydrocarbon pool mechanisms, in which the breakdown of PET may be supplied as a hydrogen donor. Overall, waste lignocellulosic biomass and plastics can be used to produce biofuels, which helps reduce the amount of solid waste that ends up in landfills. This study also revealed that future research should be focused on the reaction mechanisms of WS and PET co-pyrolysis in order to examine the synergistic interactions.

Phase-Engineered MoSe2/CeO2 Composites for Room-Temperature Gas Sensing with a Drastic Discrimination of NH3 and TEA Gases.

Detecting and distinguishing between hazardous gases with similar odors by using conventional sensor technology for safeguarding human health and ensuring food safety are significant challenges. Bulky, costly, and power-hungry devices, such as that used for gas chromatography-mass spectrometry (GC-MS), are widely employed for gas sensing. Using a single chemiresistive semiconductor or electric nose (e-nose) gas sensor to achieve this objective is difficult, mainly because of its selectivity issue. Thus, there is a need to develop new materials with tunable and versatile sensing characteristics. Phase engineering of two-dimensional materials to better utilize their physiochemical properties has attracted considerable attention. Here, we show that MoSe2 phase-transition/CeO2 composites can be effectively used to distinguish ammonia (NH3) and triethylamine (TEA) at room temperature. The phase transition of nanocomposite samples from semimetallic (1T) to semiconducting (2H) prepared at different synthesis temperatures is confirmed via X-ray photoelectron spectroscopy (XPS). A composite sensor in which the 2H phase of MoSe2 is predominant lacks discrimination capability and is less responsive to NH3 and TEA. An MoSe2/CeO2 composite sensor with a higher 1T phase content exhibits high selectivity for NH3, whereas one with a higher 2H phase content (2H > 1T) shows more selective behavior toward TEA. For example, for 50% relative humidity, the MoSe2/CeO2 sensor's signal changes from the baseline by 45% and 58% for 1 ppm of NH3 and TEA, respectively, indicating a low limit of detection (LOD) of 70 and 160 ppb, respectively. The composites' superior sensing characteristics are mainly attributed to their large specific surface area, their numerous active sites, presence of defects, and the n-n type heterojunction between MoSe2 and CeO2. The sensing mechanism is elucidated using Raman spectroscopy, XPS, and GC-MS results. Their phase-transition characteristics render MoSe2/CeO2 sensors promising for use in distributed, low-cost, and room-temperature sensor networks, and they offer new opportunities for the development of integrated advanced smart sensing technologies for environmental and healthcare.

Comparison of Essential Oil Components and Yield Parameters of Artemisia dracunculus and Artemisia dracunculoides

Medicinal and aromatic plants have attracted attention recently for their essential oil content. This study aims to compare, for the first time, essential oil of Artemisia dracunculus L. and Artemisia dracunculoides L., which are closely related species. Yield values of this Artemisia spp. were determined, and the highest drug-herb yield (119.01 kg/ha) was found for Artemisia dracunculus L. The essential oil components of these species grown under organic production conditions in Bayburt, Türkiye, were determined by the microwave hydrodistillation method for the first time and gas chromatography-mass spectrometry (GC-MS). The essential oil ratio for A. dracunculus was 1.40 %, whereas it was 1.21 % for A. dracunculoides; 42 components were found in A. dracunculus essential oil, while 38 were found in A. dracunculoides essential oil. Estragole was the most abundant essential oil component in A. dracunculus L. (69.34%) and A. dracunculoides L. (67.51%). The GC-MS results, showed that A. dracunculus L. is more suitable for use in perfumery and food industries than A. dracunculoides.

Non-destructive detection of trans-caryophyllene in early sweetpotato black spot disease using a QCM gas sensor based on modified CAU-1@ZIF-8 composite

Changes in the content of trans-caryophyllene could identify whether sweetpotatoes are infected with black spot disease. Therefore, in this study, a quartz crystal microbalance (QCM) sensor based on modified CAU-1@ZIF-8 was used for non-destructive detection of sweetpotato black spot. The experimental results showed that the constructed sensor performed best when both modified CAU-1 and ZIF-8 were present. The sensor showed a linear trend (R2 = 0.996, limit of detection (LOD) = 0.55 ppm) in response to trans-caryophyllene in the concentration range of 20–340 ppm with a sensitivity of −0.489 Hz (ppm)−1. The developed gas sensor was successfully used for the detection of trans-caryophyllene in real samples of sweetpotato. The experimental data showed a significant correlation with the results of gas chromatography-mass spectrometry (GC–MS) with a correlation coefficient of 0.970 (p < 0.01). Therefore, it could be used for early warning of black spot disease in sweetpotato.

Thermo-catalytic co-pyrolysis of waste biomass and non-recyclable polyethylene using ZSM-5 into renewable fuels and value-added chemicals

The present study deals with thermo-catalytic co-pyrolysis of peanut shells (PS) and non-recyclable polyethylene (NRPE) using ZSM-5 at varying ratios (5, 10 and 15 wt%). A tubular fixed bed reactor is used to pyrolyse at 500 °C, 50 °C min−1 heating rate and 100 mL min−1 inert gas flow rates. The feedstock was characterized via proximate analysis, elemental analysis, higher heating value (HHV), biochemical analysis, thermogravimetric analyser (TGA), Fourier transforms infrared spectroscopy (FTIR) viscosity, density, Gas chromatography-mass spectrometry (GC-MS), BET surface area, water holding capacity (WHC). Co-pyrolysis results confirmed maximum liquid yield (34.50 %) at 10 wt% of NRPE; however, adding 10 wt% ZSM-5 again boosted the liquid oil yield by 7.87 wt%. Pyrolytic oil characterization results confirmed that adding NRPE and ZSM-5 at 10 wt% decreased viscosity, acidity, and density. However, carbon content, heating value and ash content increased. FTIR examinations of PS confirmed hydrocarbons, acids, water, and oxygenated compounds. GC-MS results were confirmed by adding NRPE and ZSM-5 at 10 wt%; hydrocarbon and furfural increased by 5.31 and 5.46 %, whereas 6.01 % acids and oxygenated compounds decreased, respectively. The results of the char characterisation further supported the findings that adding NRPE (10 wt%) to PS enhanced carbon content and HHV by 11.86 % and 4.35 MJ kg−1 and decreased ash content, oxygen content, and bulk density by 0.75 %, 10.21%, and 71.98 kg m−3, respectively.

Determination of Cytotoxic Compounds of Lepista personata (Fr.) Cooke by Gas Chromatography-Mass Spectrometry (GC-MS) and Chemometrics

The cytotoxic activities of hexane, acetone, and methanol extracts of Lepista personata were evaluated against lung (H1299), prostate (LNCaP), colon (CaCo-2), and breast (MCF-7) cancer cell lines. The hexane extract of Lepista personata exhibited significant cytotoxic activity against CaCo-2 (EC50: 198.7 ± 4.9 µg/mL), LNCaP (EC50: 152.1 ± 3.8 µg/mL), and MCF-7 (EC50: 98.37 ± 2.5 µg/mL). Only the hexane extract exhibited cytotoxicity; thus, it was fractionated to enrich the cytotoxicity against the studied cancerous cell lines over a silica gel column. Gas chromatography-mass spectrometry (GC-MS) analyses and the cytotoxicity of all fractions were investigated. Principal component analysis (PCA) was applied to the GC-MS and cytotoxicity (EC50) results. According to the PCA, the cytotoxic fractions containing abundant benzoic acid (0.01–26.19%), cinnamic acid (0.01–5.63%), arachidic acid (0.01–17.93%), heneicosanoic acid (0.01–14.57%), 1-monolinolein (0.01–26.34%), stigmasterol (0.01–10.15%) and ergosterol (0.01–17.10%) were clustered. Moreover, the chemical composition comparison of hexane extract and its fractions, when evaluated together with PCA, revealed that the bioactive compounds detected as benzoic acid, cinnamic acid, azelaic acid, 1-monolinolein, stigmasterol, and ergosterol, which were concentrated in fractions 3, 6, 7, and 9, were responsible for the cytotoxic activity. When used with bioactivity and chemometric analysis, GC-MS of the fractions identified the bioactive compounds.

Survey of Medicinal and Invasive Weeds in Paddy Field – Phytochemical and GC-MS Profiling of Cyanotis axillaris R. &amp; S.

This study aims to determine the dominant weed species associated with rice crop fields in the Eppodhumvendran region of Thoothukudi district, Tamil Nadu and to analyze the phytochemicals, identify the bioactive compounds in ethanol extract using gas chromatography–mass spectrometry (GC-MS) and find their bioactivity using prediction of activity spectra for substances (PASS) prediction in Cyanotis axillaris. The documentation of medicinal weeds was carried out with the help of traditional local healers in Eppodhumvendran region. Phytochemical screening and GC-MS analysis of C. axillaris were performed to evaluate the chemical profiling of the extract. A total of 25 plant species regarded as invasive species/weeds were identified with the help of traditional local healers. The most commonly mentioned plant family was the Poaceae with a total of five species followed by the Euphorbiaceae, Asteraceae and Commelinaceae. Among these, C. axillaris is being studied for its potentiality due to its strong therapeutic value. The aerial plant part contains phytoconstituents such as alkaloids, glycosides, quinones, phenolics, steroids and terpenoids. The GC-MS results revealed 30 bioactive compounds, which were predicted using the PASS prediction method. The study highlights the importance of weeds in the paddy field ecosystem. The results reveal that C. axillaris contains various phytocomponents and that more research into their phytopharmaceutical relevance is required in the future.

Tracking contaminants in the aqueous effluent during supercritical water gasification and oxidation of swine manure in the flow mode

Biomass waste processing is an area of great interest due to its potential for reducing environmental impact and recovering resources. The present work investigates for the first time the composition of products resulting from supercritical water (SCW) gasification and oxidation of swine manure (SM) continuously fed into a tubular reactor at a temperature gradient along its vertical axis of 390–600 °C and a pressure of 25 MPa. Special attention is paid to how the operating parameters, including SM flow rate (6.5–10.7 g/min), oxidation ratio (OR ≤ 1.78), and the presence of NaOH additive (1 wt%) influenced the composition and concentration of contaminants (phenols, N-bearing aromatics, polyaromatic hydrocarbons (PAHs), and ammonia) in the effluent collected at the reactor outlet. The results of gas chromatography-mass spectrometry indicate that water-soluble products comprise predominantly of phenols, pyridines, pyrroles, indoles, pyrazines, anilines, and quinolines. Increasing the reagent’s residence time during SCW gasification was observed to lower the amount of phenols in the effluent. In addition, the introduction of NaOH increases the yields of syngas and NH3 while lowering the concentration of N-bearing aromatics and PAHs. SCW oxidation of SM not only reduces contaminant levels in the effluent by several orders of magnitude, but also partially compensates for thermal inputs needed for the process implementation. Among N-bearing compounds, ammonia, pyridines, indoles, and quinolines display the highest resistance to oxidation. The paper explores the resource-saving and ecological benefits of SCW gasification and oxidation of SM.

Evaluation of Yield, Chemical Profile, and Antimicrobial Activity of Teucrium polium L. Essential Oil Used in Iranian Folk Medicine.

Teucrium polium L. is used to treat many diseases like abdominal pains, indigestion, colds, and reproductive system diseases in Iranian folk medicine. This study was designed to investigate the yield, chemical profile of essential oil, and antibacterial and antifungal activity of this species. The flowering aerial parts of T. polium were collected from the Margh region of Kashan, Iran. The essential oil of the plant was extracted and separated using the Clevenger apparatus and analyzed using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oil against a variety of standard microbial strains was investigated with the Agar well-diffusion method and determination of the lowest growth inhibitory and lethal concentration (MIC and MBC). The results showed that the yield of T. polium essential oil (TPEO) was 0.5778%. Based on the results of GC-MS, 76 compounds (99.3%) were identified in the TPEO, of which α-pinene (9.67%), β-caryophyllene (8.07%), β-pinene (5.04%), nerolidol (4.94%), and oleic acid (4.57%) were the dominant components. The results of antimicrobial tests showed that the TPEO on Staphylococcus aureus created the largest zone of inhibition (~ 14.29 mm). The dominant inhibitory activity of this essential oil was against Gram-negative bacteria Escherichia coli (~ 9.00 mm), which was almost similar to rifampin (~ 11 mm). It seems that the predominance of terpenoid and acidic compounds of the essential oil is one of the possible factors of the anti-bacterial activity of this essential oil. Therefore, the TPEO may be a promising and potential strategy to inhibit some bacterial strains.

Cytotoxic and Antioxidant Properties of Artemisia deserti Essential Oil Obtained by Different Extraction Methods

Background: Artemisia deserti Krasch belongs to Asteraceae family, and has many medicinal properties that used to treat a variety of diseases, including antihypertensive, invigorating blood circulation, antiallergy, antiviral, antitumor, and antioxidant. Methods: The objective of this study was the evaluation of cytotoxic and antioxidant activities as well as the chemical composition of A. deserti essential oil extracted by different extraction methods. These extraction methods included hydro-distillation (HD), salt-HD (Salt pretreatment followed by HD), maceration-HD (maceration pretreatment followed by HD), acid-HD (acid pretreatment followed by HD), ultrasound-HD (ultrasound pretreatment followed by HD), and enzyme-HD (enzyme pretreatment followed by HD). Results: The results revealed that the highest yield of essential oil was achieved by acid-HD (0.48% ± 0.11%). In all methods, the main compounds of essential oil were camphor (44.32%–66.80%), piperiton (14.11%–24.33%), and 1,8-cineole (4.85%–6.75%). The antioxidant property of essential oils was investigated using the DPPH method. Based on the results, the essential oils extracted by acid-HD and enzyme-HD methods had the highest property. The cytotoxic property of A. deserti essential oils was evaluated. The results demonstrated that the essential oil extracted by enzyme-HD indicated the highest cytotoxicity activity against human cervical carcinoma (HeLa) cells in both 24 and 48 h. Based on the gas chromatography-mass spectrometry results, 1,8-cineol, carvacrol, thymol, and myristicin were rich in the essential oil extracted by enzyme-HD, and the highest cytotoxicity activity of essential oil obtained by enzyme-HD method is probably related to these compounds. Conclusion: In addition, it was observed that enzyme-HD is an effective method in the extraction of essential oil with the highest antioxidant and cytotoxic activities.

Molecular investigation into the transformation of recalcitrant dissolved organic sulfur in refinery sour water during stripping process

Refinery sour water primarily originates from the tops of towers in various units and coker condensate, and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand (COD) and organic sulfur contents. Even after the recovery of H2S from the sour water by the stripping process, the effluent still contains a high concentration of dissolved organic sulfur (DOS), which can have a huge bad influence. While chemical composition of dissolved organic matter (DOM) in refinery wastewater has been extensively studied, the investigation of recalcitrant DOS from sour waters remains unclear. In the present study, chemical composition of sour water DOMs (especially DOS) was investigated using fluorescence spectroscopy (excitation-emission matrix, EEM) and mass spectrometry, including gas chromatography-mass spectrometry (GC-MS) and high-resolution Orbitrap MS. The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process, while compounds with high hydrophilicity and humification degree were found to be more recalcitrant. The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds. However, the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms, particularly in the form of highly unsaturated and aromatic compounds. The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates, disulfide bonds, thioethers. Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.

Exploring the potential of a new marine bacterium associated with plastisphere to metabolize dibutyl phthalate and bis(2-ethylhexyl) phthalate by enrichment cultures combined with multi-omics analysis

Phthalic acid esters (PAEs) plasticizers are virulent endocrine disruptors that are mixed into plastics while fabricating and can filter out once they release into the surrounding environments. Plastic surfaces serve as new habitats for microorganisms, referred to as ‘plastisphere’. Previous metagenomic investigations of the ‘plastisphere’ indicated that marine plastic surfaces may harbor microbes that degrade PAEs plasticizers. To our knowledge, the potential of microorganisms in the marine ‘plastisphere’ to metabolize PAEs is poorly understood. In this study, by screening the natural microbial community on plastic debris that had been deployed in situ for up to 20 months, a novel marine bacterium, Microbacterium esteraromaticum DEHP-1, was successfully isolated, which could degrade and mineralize 10–200 mg/L dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). According to the results of gas chromatography-mass spectrometry (GC-MS) and whole genome mining of strain DEHP-1, we found that strain DEHP-1 may metabolize DBP by successive removal of the ester side chain by esterase 2518 to produce mono-butyl phthalate (MBP) and phthalic acid (PA), whereas the degradation of DEHP may take place by the direct action of monooxygenase 0132 on the fatty acid side chain of the DEHP molecule to produce di-n-hexyl phthalate (DnHP) and DBP, and then the subsequent hydrolysis of DBP by de-esterification to PA and finally into the tricarboxylic acid (TCA) cycle. Non-targeted metabolomics results showed that intracellular degradation of PAEs did not happen. However, exposure to PAEs was found to significantly affect pathways such as arginine and proline, riboflavin, glutathione and lysine degradation. Therefore, the intracellular metabolic behavior of strain DEHP-1 exposed to PAEs was proposed for the first time. This study sheds light on the metabolic capacity and strategies of bacteria in the marine ‘plastisphere’ to effectively degrade PAEs and highlights the importance of marine microbes in mitigating plastic poisonousness.

Controlled release of fishy odors in soluble dietary fiber/surimi mixture by kinetic analysis of real and simulated systems

This study aimed to investigate the effects and mechanisms of soluble dietary fiber (SDF), temperature and hydrophobicity on the release of fishy compounds from surimi by the preparation of real and simulated systems. The results of gas chromatography-mass spectrometry revealed 15 fishy compounds in silver carp surimi, and adding 2 wt% SDF to surimi was found to inhibit the release of 14 fishy compounds by 2.16–43.49%. The simulated release indicated that SDF matrices with different concentrations inhibited the release of fishy compounds by different mechanisms. The resistance to the release of fishy compounds was attributed to viscosity and chemisorption in 2 and 5 wt% SDF matrices, while chemisorption and entanglement network in 8 and 10 wt% SDF matrices. Moreover, high temperature and hydrophobicity of fishy compounds could promote their release by decreasing interfacial mass transfer resistance and H-bond interaction, respectively. Additionally, adding SDF changed the release pathway of fishy compounds in surimi, and they were released through the first pathway consisting of surimi intraparticle diffusion, SDF boundary layer diffusion and gas-liquid interfacial diffusion, or through the second pathway additionally including chemisorption and desorption. This study provides new insights into controlling the release of fishy odors in surimi products.

Cultivation and Nutritional Evaluation of Agaricus bisporus with Tea Residue as Culture Medium.

Different constituents of the cultivation substrate have significant effect on the yield and quality of edible mushrooms. The residue after the extraction of instant tea has exhibited to be biologically significant, and could be used as a substrate for cultivation. This study aimed to investigate the feasibility of tea extraction residue (TER) on button mushroom (Agaricus bisporus) cultivation, as an ingredient in the substrate, and assess the growth status, nutritional values, and sensory characteristics of fruiting body. The results showed that the strains could grow well on the cultivated substrate with 20% addition of TER. The total amount of hydrolyzed amino acids in the fruiting bodies of three TER-based groups (TER accounted for 10%, 20%, and 37.5%, respectively) was higher than that of the control group, and the total amount of essential amino acids was increased by 33.33%, 22.47%, and 9.92% compared with the control group, respectively. In addition, the results of gas chromatography-mass spectrometry (GC-MS) revealed that the addition of TER to the cultivation of substrate significantly enhanced the content of typical mushroom-flavor compounds in button mushroom, such as 1-octen-3-ol, 3-octanol, and 1-octen-3-one. It can be concluded that TER may be an ideal choice for the substrate in commercial cultivation of button mushroom.

Understanding the formation of efflorescence on beeswax models housed at the Natural History Museum of Florence

The Natural History Museum of Florence, and in particular “La Specola”, houses several ceroplastics collections produced in Florence in the XVIII-XIX centuries by Clemente Susini and co-workers. The collections include models of fruits and plants, vertebrate and invertebrate animals, and over 1400 anatomical waxes. All models are mainly constituted by beeswax. Although extremely resistant, the models undergo a wide range of degradation processes. Periodically, a white crystalline efflorescence, commonly called “wax bloom”, appears on the surface of the objects obviously impairing their aesthetical features.Many mechanisms have been hypothesized about the formation of these white exudates, but non univocal conclusions have yet been drawn. Our gas chromatography-mass spectrometry results indicate that wax bloom strongly depends on the composition of the models, being related to the presence of oils and fats originally used as plasticizers or pigments’ media. Thermal and X-ray measurements indicate that a poor solid-solid miscibility between the efflorescence compounds and other beeswax components leads to phase separation followed by migration of the immiscible materials towards the model surface. Besides, X-ray diffraction reveals an increased structural order of models as compared to recent beeswax certainly correlated with the increased brittleness determined by rheology measurements.

Phytochemical screening, antioxidant activity and identification of active phytochemical compounds of Scutellaria wightiana Benth. an endemic plant to peninsular India

The present investigation focuses on Scutellaria wightiana for their phytochemical and biological activities. In this investigation, ethanolic extracts of S. wightiana was tested for their phytochemical attributes by qualitative methods such as preliminary screening, gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR), antioxidant, antibacterial and bioactive compound properties. The bactericidal activity of the plant extract was evaluated using both gram+ve and gram-ve bacteria by disc diffusion method. Qualitative phytochemical analysis of the leaf extract showed the presence of alkaloids, saponins, phenols, tannins, diterpenes, flavonoids, proteins and amino acids. FTIR spectra confirmed the presence of various functional groups like alcohols, phenols, alkanes, amines, nitrogen groups and carboxylic acids. The DPPH IC50 value of ethanol extract was found to be 576.48 μg/mL and that of the hydroxyl radical scavenging activity was observed 310.87 μg/mL at the concentration of 1000 μg/ml. FRAP antioxidant capacity was found to be 88.70 μmoles/mg. Antibacterial activity of ethanol extract was higher for Staphylococcus aureus with 16 mm zone of inhibition. GC-MS results displayed various phytochemical constituents which are crucially acknowledged for their pharmacological activities.

Identification of sweetpotato black spot disease caused by Ceratocystis fimbriata by quartz crystal microbalance array

Sweetpotato black spot disease caused by Ceratocystis fimbriata is a major sweetpotato disease that not only affects yield and storage but also damages human or animal health. Herein, a four-element quartz crystal microbalance (QCM) gas sensor array based on molecularly imprinted polymers (MIPs) and zeolitic imidazolate frameworks (ZIFs) materials were reported to differentiate healthy sweetpotatoes and sick sweetpotatoes. Several volatile organic compounds, namely citronellol, heptanal, benzaldehyde, and 2-pentylfuran, were selected for detection based on the results of gas chromatography-mass spectrometry (GC-MS). The MIPs and ZIFs were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption, and the results show that materials were successfully obtained. The four sensors based on the as-prepared materials exhibited excellent sensitivity and selectivity toward target gases. Finally, the sensor array was applied to identify sick sweetpotatoes. Frequency shift was selected as the eigenvalue and quadratic support vector machine (QSVM) and weighted k-nearest neighbor (WKNN) models were employed for discrimination. QSVM and WKNN exhibited 100% accuracy in classification, proving that the sensor array can be used for the identification of Ceratocystis-fimbriata-infested sweetpotatoes. This study may contribute to the development of gas sensor arrays for use in agri-food quality control and protection.

Preparation and characterization of tea tree oil-β-cyclodextrin microcapsules with super-high encapsulation efficiency

This study aimed to prepare tea tree oil-β-cyclodextrin microcapsules using an optimized co-precipitated method. The impact of the volume fraction of ethanol in the solvent system for microencapsulation on encapsulation efficiency was investigated and analyzed sophisticatedly. Super-high encapsulation efficiency was achieved when a 40% volume fraction of ethanol was used for the microencapsulation procedure, where the recovery yield of microcapsules and the embedding fraction of tea tree oil in microcapsules were as high as 88.3% and 94.3%, respectively. Additionally, considering the operation cost, including time and energy consumption, an economical preparation was validated so that it would be viable for large-scale production. Based on the results of morphological and X-ray diffraction analysis, the crystal structure appeared to differ before and after microencapsulation. The results of gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy confirmed the successful formation of microcapsules. Furthermore, the antibacterial activity of the fabricated microcapsules was assessed by a simple growth inhibition test using Bacillus subtilis as the study object, and the hydrophilic property was proved by a water contact angle measurement.

Performances and mechanisms of ferrate(VI) oxidation process for shale gas flowback water treatment

The aim of this study was to determine effective and green methods for the removal of organic matter from shale gas flowback water (SGFW). The effects of ferrate (Fe(VI)), initial pH, and reaction time on the removal efficiency of Fe(VI) were investigated. A chemical oxygen demand removal efficiency of 57 % was achieved under the optimal conditions of Fe(VI)= 1500 mg/L, pH= 8.0, T = 25 °C, 60 min. Combined with the results of the chemical probe method, competitive kinetic experiments, electron spin resonance spectra, and radical quenching studies, hydroxyl radicals (∙OH) were demonstrated as the dominant reactive species responsible for oxidation. Furthermore, the fluorescence intensity of soluble microbial by-product-like matter and acid-like components were found to be reduced by 64 % and 43 %, respectively, using fluorescence excitation-emission matrix spectroscopy tests. The results of gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry indicated that electron-rich organic compounds were easily removed by Fe(VI) oxidation. Bacterial culture and coagulation experiments showed that Fe(VI) had both disinfection and coagulation effects in the SGFW. Furthermore, considering H2O2 as a precursor for ∙OH generation, the combined H2O2-Fe(VI) process was investigated in this study, and the results showed that the process has a synergistic effect and can increase the Chemical Oxygen Demand (COD) removal up to 68 % (Fe=1500 mg/L, pH=8.0, H2O2 =0.05 mol/L, T = 25 °C). Finally, an ultrafiltration membrane fouling experiment proved that the oxidation processes can increase the membrane-specific flux and alleviate fouling resistance. This study provides a reference for the design and operation of organic removal process in the SGFW treatment.

Phytochemical Screening Extract of Canna edulis K. by Using Gass Chromatography Mass Spectrometry

Canna edulis K. &lt;em&gt;is a tuberous crop containing starch that is frequently consumed as food. Due to the phytochemical content of canna tubers, several studies have demonstrated the use of canna tuber as an antioxidant, anticancer, antibacterial, and hepatoprotective agent. This study aims to quantitatively determine the phytochemical content of distilled water extract and ethanol extract of canna tuber, as previous research has only provided qualitative results. Old-red canna tubers were extracted using maceration and freeze-drying techniques. Using Gas Chromatography-Mass Spectrometry (GC-MS), the extraction results with two different solvent types were analyzed. According to the GC-MS results, the ethanol extract represented 32 phytochemical compounds, more abundant than the distilled water extract (16 compounds). The terpenoid compound tetradecamethylcycloheptasiloxane can be extracted with both ethanol and distilled water solvents, whereas the polysaccharide compounds D-Mannitol, 2-Deoxy-D-ribose, and d-Mannose can only be extracted with ethanol solvent. The results of the phytochemical analysis of canna tuber extract are expected to be utilized as pharmaceuticals or alternative food ingredients.&lt;/em&gt;