Volatile Solid and Bury Period Influence on Odorous Material Production in Simulating Landfill Treatment

Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.

Release of volatile organic compounds during bio-drying of municipal solid waste

Three treatments were tested to investigate the release concentrations of volatile organic compounds （VOCs） during the bio-drying of municipal solid waste （MSW） by the aerobic and combined hydrolytic-aerobic processes.Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were：dimethyl disulfide,dimethyl sulfide,benzene,2-butanone,limonene and methylene chloride.Thus,the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process,and the treatment strategies should base on the key properties of these prominent components.Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying,whereas,two peaks of release concentrations appeared for aromatics and ketones during bio-drying.Notably,for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages.High concentrations of released chlorinateds were observed in the later phase.For the VOCs produced during MSW bio-drying,i.e.,malodorous sulfur compounds,terpenes and chlorinateds,their release concentrations were mainly determined by production rates;for the VOCs presented initially in MSW,such as aromatics,their transfer and transport in MSW mainly determined the release concentrations.

Comparison of Headspace Solid-Phase Microextraction with Simultaneous Steam Distillation Extraction for the Analysis of the Volatile Constituents in Chinese Apricot

Volatile constituents in fully mature fruits of apricot （Prunus armeniaca L.） cultivar Xinshiji were extracted using headspace solid-phase microextraction （HS-SPME） and simultaneous steam distillation extraction （SSDE） and then analyzed using capillary gas chromatography and gas chromatography-mass spectrometry. A total of 70 components were identified by HSSPME, including 20 esters, 19 hydrocarbons, 5 alcohols, 5 ketones, 4 acids, 4 lactones, 3 aldehydes, and 10 miscellaneous components, with the esters being the dominant constituent. On the basis of the odor unit values, it is believed that the following compounds probably contributed to the fresh apricot odor： hexyl acetate, β-ionone, butyl acetate, （E）-2-hexenal, linalool, limonene, γ-decalactone, and hexanal. A total of 49 components were also detected by SSDE, including 13 hydrocarbons, 9 alcohols, 7 aldehydes, 9 esters, 4 ketones, 4 lactones, 2 acids, and 1 miscellaneous component, of which the monoterpene alcohols were the dominant constituents. It could be judged from the odor unit values that the following compounds were the major contributors to boiled apricot aroma： β-ionone, linalool, hexyl acetate, γ-dodecalactone, γ- decalactone, （E）-2-hexenal, hexanal, γ-octalactone, phenylacetaldehyde, butyl acetate, limonene, α-terpineol, and δ-decalactone. The results show that HS-SPME is a simple, rapid, and solvent-free method, which is an alternative to the classical SSDE.

Integration of GC-MS Based Non-Targeted Metabolic Profiling with Headspace Solid Phase Microextraction Enhances the Understanding of Volatile Differentiation in Tobacco Leaves from North Carolina, India and Brazil

In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.

SlMYB75,an MYB-type transcription factor,promotes anthocyanin accumulation and enhances volatile aroma production in tomato fruits

Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.

Differential volatile organic compounds in royal jelly associated with different nectar plants

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

Volatile components of Rhizoma Alpiniae Officinarum using three different extraction methods combined with gas chromatography-mass spectrometry

Volatile components from Rhizoma Alpiniae Officinarum were respectively extracted by three methods including hydrodistillation, headspace solid-phase microextraction （HS-SPME） and diethyl ether extraction. A total of 40 （hydrodistillation）, 32 （HS-SPME） and 37 （diethyl ether extraction） compounds were respectively identified by gas chromatography-mass spectrometry （GC/MS） and 22 compounds were overlapped, including β-farnesene, 7-muurolene, 2,6-dimethyl-6- （4-methyl-3-pentenyl）bicyclo[3.1.1]hept-2-ene, eucalyptol and cadina-1（10）, 4-diene and so forth, varying in relative contents. HS-SPME is fast, sample saving and solvent-free and it also can achieve similar profiles as those from hydrodistillation and solvent extraction. Therefore, it can be the priority for extracting volatile components from medicinal plants.

Volatile Flavor Composition in Mutton of Ningxia Tan Sheep

[Objective] To analyze the volatile flavor compounds in mutton of different parts of Ningxia Tan sheep. [Method] The volatile flavor compounds in mutton were identified and quantified using the solid phase micro-extraction （SPME） method combined with GC-MS analysis. [ Re- sult ] The proportion of aldehydes in volatile compounds was the highest in the mutton of most parts of Ningxia Tan sheep, but no 4-methyl acid and 4-methyl nonyl acid was detected in the mutton. [ Conclusion]Aldehydes may be important for the volatile flavor of mutton of Ningxia Tan sheep. The study provides a basis for better development and use of Ningxia Tan sheep.

Analysis on Volatile Components of Flowers and Leaves of Thymus mongolicus by SPME-GC/MS

[Objectives] To analyze volatile components of flowers and leaves of Thymus mongolicus. [Methods]Volatile components of collected T. mongolicus flower and leaves were separated by headspace solid-phase microextraction( SPME) and identified by gas chromatography/mass spectrometry( GC/MS) and normallized by peak area. [Results] A total of 24 and 14 compounds were identified from flowers and leaves of T. mongolicus in the total ion chromatogram,accounting for 99. 573% and 97. 187% of the total peak area,respectively. Main components of flowers and leaves of T. mongolicus include phenols and terpenes,and thymol accounts for 35. 38% and 49. 13% of flowers and leaves of T. mongolicus,respectively. [Conclusions] SPME-GC/MS can be applied in analyzing volatile components of flowers and leaves of T. mongolicus,to provide basis for further development and utilization of T. mongolicus.

Effects of Grafting on Volatile Compounds in Bitter Gourd Fruit

[Objectives]This study was conducted to explore the effects of grafting on volatile compounds in bitter gourd fruit.[Methods]The volatile compounds and relative contents of grafted and non-grafted fruit were analyzed by headspace solid phase micro-extraction with gas chromatography-mass spectrometry.[Results]There were 59 volatile compounds in Haiyan No.2S,including six unique compounds.There were 58 volatile compounds in Haiyan No.2J,including five unique compounds.[Conclusions]This study provides a scientific basis for further analysis of bitter gourd flavor regulation mediated by grafting.

Analysis of Volatile Components in Different Parts of Polygala japonica Houtt.

[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.

上海股票市场波动不对称性研究—GJR-与VS-GARCH模型的比较

分析了两个不对称的GARCH模型:G JR-GARCH和VS-GARCH,并对VS-GARCH进行了修正。使用上证综合指数对两个模型进行了实证比较,发现修正的VS-GARCH更适合中国证券市场,能更好的捕捉到波动的不对称性。同时实证结果显示在沪市上,好消息引发的波动大于坏消息引发的波动,并从交易规则和投资者心理方面进行了解释。

基于VS的有机固体废物厌氧消化的趋势分析

在表示有机固废厌氧消化进程的三个指标(COD、TS、VS)中,VS是有代表性的指标。VS在整个厌氧消化过程中呈下降的趋势,同时,VS的变化是连续的,由此,可以用一元多项式和指数函数模型来预测有机固废厌氧消化过程中VS的变化。通过研制的混合式厌氧发酵自动控制实验装置(简称为MADACE)验证了两模型的可行性,其相关系数均达到了0.98以上。

优化HS-SPME-GC-MS方法表征香菇不同成熟阶段的关键挥发性化合物

通过优化的顶空固相微萃取结合气相色谱-质谱联用技术鉴定香菇不同成熟阶段挥发性化合物,并采用气味活性值(odor activity value,OAV)和偏最小二乘判别分析(partial least squares discriminant analysis,PLS-DA)进行分析。结果表明:最佳提取条件为1.0 g香菇样品在50℃提取25 min,解吸3 min;在香菇不同成熟阶段共鉴定出71种挥发性化合物,不同成熟阶段挥发性化合物种类和含量存在显著差异(P<0.05);通过PLS-DA和变量投影重要性(variable importance in projection,VIP)筛选出18种挥发性化合物,可作为区分香菇不同成熟阶段的挥发性生物标志物;OAV结果表明,有16种挥发性化合物为香气活性化合物,其中,1-辛烯-3-醇、3-辛醇、1-辛烯-3-酮、3-辛酮、苯乙醛、二甲基二硫醚、二甲基三硫醚、2,3,5-三硫杂己烷和1,2,4-三硫杂环戊烷同时满足VIP>1和OAV≥1,是香菇不同成熟阶段最重要的差异挥发性化合物。本研究为探究香菇成熟过程中香气形成机制提供一定理论依据。

From public to private solid waste management:Stakeholders’perspectives on private-public solid waste management in Lobatse,Botswana

Upon the realization that urban areas can only achieve sustainable solid waste management systems through an interplay of partnerships and stakeholders,developing countries have geared themselves towards the privatization of waste management services in efforts to reduce costs and improve efficiency.Lobatse,a town located in the south of Botswana,faces the increasing challenges of poor waste management due to the lack of finances and resources available to the Lobatse Town Council,which hinders efforts towards a sustainable waste management system.This has negative implications for public health and the environment,as a result of solid waste pollution from littering and the illegal dumping of waste.This work examines the current state of solid waste management and its challenges in Lobatse,within the context of the interplay between public and private solid waste management.The study aims to perform a social exploration of the efficiency of waste management services,considering the political economy and households’perceptions towards these services.Key stakeholders were interviewed and a social survey of 222 households was conducted to generate primary data.The findings indicate that the involvement of the private sector yielded positive outcomes,as it increased the solid waste collection frequency and improved the quality of the waste management service.Most of the stakeholders were in favor of privatization,and the households were satisfied and willing to contribute towards the cost recovery of solid waste management.It is,therefore,recommended to promote and establish a private-public-community partnership in the town to improve the quality of the waste management system.

不同产地沃柑挥发性成分的差异分析

该研究旨在分析4个主产地(四川、重庆、云南和广西)的沃柑果皮中挥发性成分的差异性,并为沃柑的产地溯源和深加工提供数据支撑。利用顶空固相微萃取-气相色谱-质谱联用技术测定了沃柑果皮挥发性成分,共鉴定出50种挥发性成分,其中萜烯类18种、醇类11种、醛类10种、酯类8种、酮类1种、其他类2种。柠檬烯是主要的挥发性物质,月桂烯、α-蒎烯、芳樟醇、正辛醇、正辛醛、香茅醇、己醛、反式-2-己烯醛、桧烯、香芹酮和α-松油醇等次之。基于挥发性成分半定量结果,建立四川和重庆,云南和广西沃柑的正交偏最小二乘法判别分析模型,进而筛选出潜在生物标志物。结果表明,柠檬烯、芳樟醇和香茅醇可作为区分重庆和四川的潜在生物标志物,醋酸辛酯和α-松油醇可作为区分广西和云南的潜在生物标志物。

基于HS-SPME-GC-MS的不同成熟度‘青皮’无花果挥发性成分分析

为探讨不同成熟度威海‘青皮’无花果挥发性成分差异,本研究采用固相微萃取(SPME)和气相色谱-质谱联用技术(GC-MS)对鲜食无花果挥发性成分进行分析,并采用内标法对风味物质进行定量分析。结果显示,在威海‘青皮’无花果中共检测出73种挥发性成分,主要为酯类、醛类、醇类、烯类、烷烃类等,其中六成熟无花果检出33种、八成熟检出29种、十成熟检出36种。不同成熟度无花果的挥发性组分、特征风味物质种类和含量差异明显。

不同萃取方法下绿萼梅花蕾挥发性成分的差异研究

2023年3月13日,从浙江省长兴县东方梅园有限公司梅花基地采集绿萼梅花蕾,采用顶空-固相微萃取、水蒸气蒸馏、超临界二氧化碳3种萃取方法,结合气相色谱-质谱联用仪(GC-MS)分析绿萼梅Prunus mume f.viridicalyx花蕾中的挥发性成分,以明确其花蕾中挥发性成分组成、含量及不同萃取方式对挥发性成分萃取效果的影响。结果表明,三种萃取方法获得的绿萼梅花提取物中共鉴定出醛、醇、酮、烯等9类57种化合物,主要挥发性成分是苯甲醛、壬醛、金合欢醇、苯甲酸、α-香树脂醇、D-柠檬烯,其中苯甲醛含量最高。绿萼梅花顶空-固相微萃取物中共鉴定出21种化合物,以醛、醇和酯类化合物为主;水蒸气蒸馏物中共鉴定出30种化合物,以酯、烯、酮等水难溶化合物为主;而超临界二氧化碳提取物中共鉴定出30种化合物,以长链烷、酯类化合物为主。三种提取方法中超临界二氧化碳萃取物中蜡质含量较高,顶空-固相微萃取和水蒸气蒸馏法结合更适合作为植物芳香类挥发物的检测手段。

基于多元统计学分析^(60)Co-γ射线辐照对川芎挥发性成分的影响

川芎挥发性成分是其主要活性成分之一,也是评价川芎药用品质的重要指标。为探究^(60)Co-γ射线辐照对川芎挥发性成分的影响,本研究以不同吸收剂量处理川芎样品,采用电子鼻结合顶空固相微萃取-气相色谱-质谱技术(HS-SPME-GC-MS),通过主成分分析、线性判别分析、正交偏最小二乘法和聚类分析的多元统计学方法分析数据,以期了解川芎辐照前后挥发性成分的变化。电子鼻与GC-MS结果都表明:川芎气味主要由烷烃类、醇类、醛类、酮类贡献,10 kGy剂量以下的辐照处理对川芎挥发性气味成分影响不大;川芎经0 kGy(对照组)、3 kGy、7 kGy、10 kGy剂量辐照处理后,共鉴定出60种化合物,其中烃类23种,醇类12种,脂类10种,醛酮类4种,其他类11种;筛选到21种辐照前后的差异特征性指标物,它们在川芎挥发性成分中只占约12.92%,不是川芎的主要挥发性成分。经10 kGy剂量以下的辐照处理后,川芎中没有新生成的物质被鉴定出来。研究结果提示经10 kGy以下剂量处理川芎不会影响其主要挥发性成分。

基于顶空固相微萃取-气相色谱-质谱法分析加速氧化过程中全脂牛羊乳粉挥发性化合物

为探究全脂牛羊乳粉在储存过程中风味物质的变化,本研究采用顶空固相微萃取-气相色谱-质谱技术对加速氧化过程中全脂牛羊乳粉挥发性化合物进行分析。研究表明,全脂牛乳粉和全脂羊乳粉中分别鉴定出56、63种挥发性物质,主要为酸类、醇类、羰基类、酯类、芳香族类、杂环类等挥发性化合物。通过主成分分析和聚类热图分析,在全脂牛羊乳粉中筛选出10种显著性差异挥发性化合物,全脂牛乳粉在储存过程中丁酸相对含量降低,2-壬酮、1-氯戊烷相对含量升高;全脂羊乳粉中壬醛、辛酸、丙酸、丁羟甲苯相对含量降低,苯甲醛、2-庚酮、烯丙基正丙酯相对含量升高。