Determination of Aromatic Components of Rosa davurica Pall. by Headspace Solid Phase Microextraction Combined with GC-MS

[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.

Determination of organochlorine pesticides from juice samples using magnetic biochar-based dispersive micro-solid phase extraction in combination with dispersive liquid-liquid microextraction

Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.

大鼠尿液中硝基安定代谢物的GC-MS检验

The metabolites and metabolic passways of nitrazepam in rat were confirmed.Wistar rats were feed a pill of nitrazepam,24 h urine reactions were collected.After β-Glucuronidase hydrolysis of the urine samples,the fractions were extracted by Oasis HLB3cc solid-phase column and analyzed by gas chromatography-mass spectrometry with DB-35 MS column.7-Acetylaminonitrazepam,7-aminonitrazepam and 2-amino-5-nitrophenylphenylmethanone were identified as nitrazepam metabolites.The results suggested that two metabolic passways for nitrazepam may be operative in rat.The first passway leads to the corresponding 7-aminonimetazepam in which the amino group is subsequently acetylated.The second passway is open the parent compounds rings to 2-amino-5-nitrophenylphenylmethanone.Nitrazepam was metabolized quickly in rats and 7-acetylaminonitrazepam were the main metabolites in urine.

福建姜黄挥发油化学成分的HS-SPME-GC-MS分析

采用水蒸气蒸馏法提取福建姜黄挥发油,应用顶空固相微萃取进样结合气相色谱-串联质谱联用技术(HS-SPME-GC-MS)分析姜黄挥发油的化学成分。结果表明:姜黄挥发油含有量为7.2%(mL/g),从姜黄挥发油中共分出62个色谱峰,初步鉴定出了其中的51种化学成分,占总挥发油总量的98.41%。在鉴定的化合物中,主要为单萜类化合物和倍半萜类化合物,其中新发现一种主要成分为β-柏木烯,相对含量占比高达26.58%,这可作为福建姜黄挥发油的特征成分和主要品质指标。本研究结果将为福建姜黄植物药材的品质评价提供科学依据。

六种特级初榨橄榄油挥发性香气成分的比较

为探究比较特级初榨橄榄油挥发性香气成分,采用固相微萃取(solid phase micro-extraction,SPME)结合气相色谱嗅闻质谱(gas chromatography-olfactrometry-mass spectrometry,GC-O-MS)联用、感官评价和电子鼻技术对3个国家的6种特级初榨橄榄油挥发性香气成分进行分析。结果表明,电子鼻可以明显区分不同橄榄油;GC-O-MS通过极性色谱柱(DB-Wax)和非极性色谱柱(DB-5)结合分析,鉴定得出65种挥发性香气活性化合物,包括醛类16种,醇类12种,酯类9种,酮类6种,烯烃及萜烯类8种,芳香类5种,酸类3种及6种其他类型化合物。结合文献、检测及嗅闻结果得出特级初榨橄榄油中的特征香气成分为反-2-己烯醛、己醛、反-2-壬烯醛、6-甲基-5-庚烯-2-酮和顺-3-己烯-1-醇等以醛醇为代表的小分子化合物。

Determination of Volatile Constituents,Total Flavonoids and Total Polysaccharides in the Roots of Artemisia argyi Levl. et Van. var.argyi cv. Qiai

[Objectives] To analyze the volatile components,the contents of total flavonoids and total polysaccharides of the roots of Artemisia argyi Levl. et Van. var. argyi cv. Qiai,and to provide a scientific basis for the comprehensive development and utilization of the resources.[Methods]The volatile components of the roots were extracted by solid phase micro-extraction( SPME),and its volatile components were analyzed by gas chromatography-mass spectrometry( GC-MS); the contents of total flavonoids and total polysaccharides in the samples were measured by UV-spectrophotometry. [Results] 44 peaks were isolated from the roots and 30 components were identified,accounting for 80. 9% of the total volatile components; the content of total flavonoids in the roots was 9. 42%; the content of total polysaccharides in the roots was 11. 05%.[Conclusions] After a comprehensive investigation,the olefins in the roots generally have antibacterial activity,the contents of the total flavonoids and total polysaccharides contained in the roots were relatively high,the roots of Artemisia argyi do have broad prospects for the development.

<i>Artemisia vulgaris</i>L. Chemotypes

Artemisia vulgaris L. was collected from various regions in the USA and Montreal Canada. Gas Chromatography-Mass Spectrometry was used to identify the analytes present in the volatiles extracted by headspace solid-phase microextraction of the crushed leaves and flowers. Four distinct chemotypes are were found: One featuring the coexistence of ar-curcumene and α-zingiberene;two marked by the presence or absence of thujone and santolinatriene;and a fourth characterized by the presence of crysanthenyl acetate (40%). DNA was used to confirm the identity of Artemisia vulgaris L.

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.

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.

Developing an authentication approach using SPME-GC-IRMS based on compound-specific δ^(13)C analysis of six typical volatiles in wine

An analytical method using gas chromatography isotope ratio mass spectrometry(GC-IRMS)combined with solid phase micro-extraction(SPME)was developed to measure the 613C values of six typical volatiles commonly occurring in wine(isoamyl acetate,2-octanone,limonene,2-phenylethanol,ethyl octanoate and ethyl decanoate)for the first time.SPME selected with a divinylbenzene/carboxen/polydimethylsiloxane fiber was combined with the GC-IRMS for pretreatment optimization.The optimized SPME parameters of extraction time,extraction temperature and salt concentration were 40 min,40℃ and 10%,respectively.The 613C values measured by SPME-GC-IRMS were in good agreement with those measured via elemental analyzer(EA)-IRMS and GC-IRMS.The differences range from 0.02‰to 0.44‰ with EA-IRMS and from 0 to 0.28‰ with GC-IRMS,indicating the high accuracy of the method.This newly established method measured the precision within 0.30‰ and was successfully validated to discriminate imported real wine samples with identical label but amazing price differences from different importers.