scholarly journals Volatile Emissions and Relative Attraction of the Fungal Symbionts of Tea Shot Hole Borer (Coleoptera: Curculionidae)

Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 97
Author(s):  
Paul E. Kendra ◽  
Nurhayat Tabanca ◽  
Luisa F. Cruz ◽  
Octavio Menocal ◽  
Elena Q. Schnell ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fungal Pathogens ◽  
Solid Phase ◽  
Volatile Emissions ◽  
Temporal Study ◽  
Pure Cultures ◽  
Symbiotic Fungi ◽  
Gas Chromatography Mass Spectroscopy ◽  
Female Attractant ◽  
Fusarium Dieback

Euwallacea perbrevis is an ambrosia beetle that vectors fungal pathogens causing Fusarium dieback in Florida avocado trees. Current monitoring lures contain quercivorol, a fungus-produced volatile, but the exact attractant is unknown since lures contain a mixture of p-menth-2-en-1-ol isomers and both α- and β-phellandrene. This study used pure cultures of six symbiotic fungi isolated from E. perbrevis to document volatile emissions and determine the relative attraction of symbionts in binary choice assays. In a comparative test, headspace solid-phase microextraction followed by gas chromatography–mass spectroscopy was used to identify and quantify emissions from 3-week-old cultures. In a temporal study, Super-Q collection followed by gas chromatography–flame ionization detection was used to measure cis- and trans-p-menth-2-en-1-ol emissions for three months. A total of 15 compounds were detected, with monoterpene hydrocarbons and oxygenated monoterpenoids predominating. Only trans-p-menth-2-en-1-ol was common to all six symbionts. Peak levels of both isomers were observed at day 7, then gradually declined over a 90 day period. In choice tests, avocado sawdust disks inoculated with Fusarium sp. nov. were the most attractive. This symbiont produced only two volatiles, trans-p-menth-2-en-1-ol and limonene. The combined results indicate that trans-p-menth-2-en-1-ol is the primary female attractant emitted from symbiotic fungi, but limonene may be a secondary attractant of E. perbrevis.

scholarly journals The Pear Aroma in the Austrian Pinot Blanc Wine Variety: Evaluation by Means of Sensorial-Analytical-Typograms with regard to Vintage, Wine Styles, and Origin of Wines

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Christian Philipp ◽  
Phillip Eder ◽  
Walter Brandes ◽  
Elsa Patzl-Fischerleitner ◽  
Reinhard Eder
Keyword(s):  
Gas Chromatography ◽  
Stable Isotope ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Stable Isotope Dilution ◽  
Isotope Dilution Assay ◽  
Dilution Assay ◽  
Consumer Study ◽  
Gas Chromatography Mass Spectroscopy ◽  
Chain Ester

The perceived pear aroma in wines was associated with various short- and medium-chain ester compounds. A consumer study confirmed this assumption. In total, eight ester compounds from a series of 100 aromatic substances were associated with the pear aroma. In this study, a valid stable isotope dilution assay headspace solid-phase microextraction gas chromatography mass spectroscopy (SIDA-HS-SPME-GC-MS) method was developed for the analysis of these compounds, and 102 Austrian Pinot blanc wines of vintages 2013–2016 were analysed. They were assessed with regard to vintage and origin influences as well as wine styles. However, an attempt was made to capture the synergies of these compounds for the pear aroma. With the detection of ethyl (E,Z)-2,4-decadienoate and methyl (E)-geranoate, two volatile compounds were measured which had not previously been detected in Austrian wines. The eight analysed esters were perceived very differently. Therefore, specific odour activity values for the various sensations could be calculated with a mathematical combination of the analyses and the results of the sensory studies. A vintage influence on the sensorial descriptor “overripe pear” and a relationship between wine style and total pear aroma were determined.

Enzymatic digestion, solid-phase extraction, and gas chromatography/mass spectrometry of derivatized intact oxazepam in urine

1991 ◽  
Vol 37 (9) ◽  
pp. 1595-1601 ◽  
Author(s):  
J G Langner ◽  
B K Gan ◽  
R H Liu ◽  
L D Baugh ◽  
P Chand ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Solid Phase ◽  
Internal Standard ◽  
Enzymatic Digestion ◽  
Gas Chromatography Mass Spectrometry ◽  
Extraction Recovery ◽  
Mass Selective Detector ◽  
Operation Conditions ◽  
Ms Analysis ◽  
Gas Chromatography Mass Spectroscopy

Abstract Enzymatic digestion with beta-glucuronidase (EC 3.2.1.31) was used to release intact oxazepam from urine samples containing the d5-analog internal standard. The resulting specimens were extracted with Du Pont PREP Type W cartridge (processed by a PREP Automated Sample Processor), Bond Elut Certify, and J.T. Baker "spe" columns for comparison of the columns' extraction recovery and overall effectiveness. Methyl iodide/tetrahexylammonium hydrogen sulfate and N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (10 g/L) were used for the methylation and trimethylsilylation studies. We used a Hewlett-Packard HP 5790 mass-selective detector equipped with a 13-m J & W DB-5 column (5% phenyl polysiloxane phase) for gas chromatography/mass spectroscopy (GC/MS) analysis and the Thru-Put Target software package for data processing. After several exploratory experiments, we adopted the Du Pont PREP system methylation procedure because of its effective recovery, the superior stability of the derivatization product, the possibility of incorporating a clean-up step, and the potential for high throughput. The extraction recovery from a set of control samples was 87%. Coefficients of variation obtained for six replicates of GC/MS analysis and for the overall procedure were 1% and 3%, respectively. Excellent linearity was established in the 50-8000 micrograms/L concentration range studied. With the use of 3-mL samples, a 20-microL final reconstitution volume, oxazepam at 50 micrograms/L was easily detected under the adopted operation conditions.

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