scholarly journals Determination of Organosulfides from Onion Oil

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 884 ◽  
Author(s):  
Maranda S. Cantrell ◽  
Jared T. Seale ◽  
Sergio A. Arispe ◽  
Owen M. McDougal
Keyword(s):  
Diethyl Ether ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Agricultural Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Diallyl Disulfide ◽  
Reference Standard ◽  
Internal Reference ◽  
Internal Reference Standard

Qualitative and semi-quantitative analysis of organosulfides extracted from oil obtained by steam distillation of yellow onions was performed by gas chromatography-mass spectrometry (GC-MS). The extraction efficiency of organosulfides from onion oil was evaluated across four solvents: dichloromethane; diethyl ether; n-pentane; and hexanes. Analysis of solvent extracted organosulfides by GC-MS provided qualitative results that support the use of dichloromethane over other solvents based on identification of 27 organosulfides from the dichloromethane extract as compared to 10 from diethyl ether; 19 from n-pentane; and 17 from hexanes. Semi-quantitative evaluation of organosulfides present in the dichloromethane extract was performed using diallyl disulfide as the internal reference standard. Three organosulfides were detected in the extract at ≥5 mg/kg; 18 organosulfides between 3–5 mg/kg; and six organosulfides at <3 mg/kg. The E/Z isomers of 1-propenyl propyl trisulfide were among the most prevalent components extracted from the onion oil across all solvents; and 3,6-diethyl-1,2,4,5-tetrathiane was among the most abundant organosulfides in all solvents except hexanes. The method described here for the extraction of organosulfides from steam distilled onion oil surveys common solvents to arrive at a qualitative and semi-quantitative method of analysis for agricultural products involving onions; onion oil; and secondary metabolites of Allium spp.

scholarly journals The GC/MS Analysis of Volatile Components Extracted by Different Methods fromExocarpium Citri Grandis

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Zhisheng Xie ◽  
Qundi Liu ◽  
Zhikun Liang ◽  
Mingqian Zhao ◽  
Xiaoxue Yu ◽  
...  
Keyword(s):  
Solid Phase Microextraction ◽  
Large Scale ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Components ◽  
Germacrene D ◽  
Long Time ◽  
Sample Amount

Volatile components fromExocarpium Citri Grandis(ECG) were, respectively, extracted by three methods, that is, steam distillation (SD), headspace solid-phase microextraction (HS-SPME), and solvent extraction (SE). A total of 81 compounds were identified by gas chromatography-mass spectrometry including 77 (SD), 56 (HS-SPME), and 48 (SE) compounds, respectively. Despite of the extraction method, terpenes (39.98~57.81%) were the main volatile components of ECG, mainly germacrene-D, limonene, 2,6,8,10,14-hexadecapentaene, 2,6,11,15-tetramethyl-, (E,E,E)-, andtrans-caryophyllene. Comparison was made among the three methods in terms of extraction profile and property. SD relatively gave an entire profile of volatile in ECG by long-time extraction; SE enabled the analysis of low volatility and high molecular weight compounds but lost some volatiles components; HS-SPME generated satisfactory extraction efficiency and gave similar results to those of SD at analytical level when consuming less sample amount, shorter extraction time, and simpler procedure. Although SD and SE were treated as traditionally preparative extractive techniques for volatiles in both small batches and large scale, HS-SPME coupled with GC/MS could be useful and appropriative for the rapid extraction and qualitative analysis of volatile components from medicinal plants at analytical level.

scholarly journals Histogram score contributes for reliability of DNA content estimatives in Brachiaria spp

2012 ◽  
Vol 36 (6) ◽  
pp. 599-607
Author(s):  
Ana Luiza de Oliveira Timbó ◽  
Roselaine Cristina Pereira ◽  
Vanderley Borges dos Santos ◽  
Fausto Souza Sobrinho ◽  
Lisete Chamma Davide
Keyword(s):  
Flow Cytometry ◽  
Dna Content ◽  
Raphanus Sativus ◽  
Triploid Hybrid ◽  
Reference Standard ◽  
Internal Reference ◽  
Ploidy Levels ◽  
Buffer Solutions ◽  
Internal Reference Standard ◽  
Content Analyses

Flow cytometry allows to estimate the DNA content of a large number of plants quickly. However, inadequate protocols can compromise the reliability of these estimates leading to variations in the values of DNA content the same species. The objective of this study was to propose an efficient protocol to estimate the DNA content of Brachiaria spp. genotypes with different ploidy levels using flow cytometry. We evaluated four genotypes (B. ruziziensis diploid and artificially tetraploidized; a tetraploid B. brizantha and a natural triploid hybrid), three buffer solutions (MgSO4, Galbraith and Tris-HCl) and three species as internal reference standards (Raphanus sativus, Solanum lycopersicum e Pisum sativum). The variables measured were: histogram score (1-5), coefficient of variation and estimation of DNA content. The best combination for the analysis of Brachiaria spp. DNA content was the use of MgSO4 buffer with R. sativus as a internal reference standard. Genome sizes expressed in picograms of DNA are presented for all genotypes and the importance of the histogram score on the results reliability of DNA content analyses were discussed.

scholarly journals Determination of Polycyclic Aromatic Hydrocarbons in Agricultural Products

2021 ◽  
Vol 16 (3) ◽  
pp. 127-136
Author(s):  
К.К. Tsymbaliuk ◽  
O.V. Snurnikova ◽  
K.V. Melnyk ◽  
E.M. Fadeev ◽  
V.P. Antonovich
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Matrix Effects ◽  
Soxhlet Extraction ◽  
Agricultural Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Polycyclic Aromatic ◽  
Optimized Conditions ◽  
Gas Chromatographic Separation

The procedure for the determination of polycyclic aromatic hydrocarbons (PAH) in agricultural products on the example of five crops (rapeseed, sunflower, flax, corn, soybeans) by gas chromatography mass spectrometry (GC-MS) was developed. It was showed the advantage of using binary mixtures of organic solvents "hexanedichloromethane" for PAH extraction. The time of Soxhlet extraction is from 6 to 8 hours at optimized conditions. The fractionation and purification of extracts by column chromatography on deactivated alumina was optimized. The article presents the optimization of sample injection in the programmed temperature vaporization (PTV) mode, parameters of gas chromatographic separation and mass spectrometric detection in determining 16 priority PAH in agricultural products. The recoveries, correctness and accuracy of the proposed method were checked by “spikes” with concentrations 0.5, 1.0, 2.5, 5.0 μg kg-1. The linearity of the method was determined by calibration curves obtained for three measurements of calibration solutions with concentrations of 0.5-100 ng mL-1. The effectiveness of the proposed combination of sample preparation and analysis by PTV-GC-MS was studied for linearity, accuracy, matrix effects and reproducibility. The method was validated by linearity, accuracy, matrix effect and reproducibility.

Monitoring diazepam and desmethyldiazepam concentrations in plasma by gas-liquid chromatography, with use of a nitrogen-sensitive detector.

1979 ◽  
Vol 25 (1) ◽  
pp. 137-140 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Liquid Chromatography ◽  
Acid Hydrolysis ◽  
Active Metabolite ◽  
Mineral Acid ◽  
Gas Liquid Chromatography ◽  
Sensitive Detector ◽  
Reference Standard ◽  
Internal Reference ◽  
Internal Reference Standard ◽  
Pharmacologically Active

Abstract We describe a modified [from Anal. Chem. 36, 2099 (1964)] procedure for determining diazepam and its pharmacologically active metabolite, desmethyldiazepam, in plasma, with use of a nitrogen-sensitive detector in the gas-liquid chromatography. We used medazepam as the internal reference standard. Diazepam and desmethyldiazepam are converted to their respective benzophenones by mineral acid hydrolysis. With this procedure, as little as 100 muL of plasma can be used to determine the drug in concentrations as low as 10 microgram/L, accurately, reproducibly, and quickly. Within-run and between-run CVs for 100 microgram/L concentrations of the two compounds were 5 and 7%, respectively.

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