Identification of Wood between Phoebe Zhennan and Machilus Pingii Using the Gas Chromatography-Mass Spectrometry Direct Injection Technique

2013 ◽  
Vol 19 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Bin Xu ◽  
Tao Zhu ◽  
Jingya Li ◽  
Shuai Liu
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Direct Injection ◽  
Gas Chromatography Mass Spectrometry ◽  
Injection Technique ◽  
Chromatography Mass Spectrometry ◽  
Phoebe Zhennan

Evaluation of volatile compounds in different types of ghee using direct injection with gas chromatography-mass spectrometry

2002 ◽  
Vol 69 (1) ◽  
pp. 163-171 ◽  
Author(s):  
UDAY R. WADODKAR ◽  
JAGJIT S. PUNJRATH ◽  
AMRISH C. SHAH
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Gas Chromatography ◽  
Volatile Compounds ◽  
Direct Injection ◽  
Gas Chromatography Mass Spectrometry ◽  
Local Market ◽  
Butter Oil ◽  
Chromatography Mass Spectrometry ◽  
Different Types

Desi ghee (DG) was prepared from fermented cream followed by heat clarification (desi method) in the laboratory and butter oil (BO) was prepared from fresh butter by melting and centrifugation. Fresh samples of three brands of industrial ghee (IG-1, IG-2, IG-3) were collected from the local market. Volatile compounds of desi and industrial ghee and butter oil were isolated and concentrated using direct injection and cryofocussing techniques; separation and identification was by Gas Chromatography Mass Spectrometry (GCMS). A maximum of 36 compounds were detected in desi ghee whereas compounds detected in three industrial ghee samples varied from 22–29. The lowest number of compounds (16) was detected in butter oil. Of the identified compounds, maltol, 5-hydroxymethyl furfuraldehyde, dihydrodihydroxypyranone, 1,3-butanediol and 1-octanol were identified only in desi ghee volatiles. The concentration of acetic acid was found to be remarkably higher in desi ghee volatiles than in industrial ghee. Also the levels of identified fatty acids, methyl ketones, aldehydes, lactones and alcohols were high in desi ghee volatiles compared with industrial ghee and butter oil. In total, 62 compounds were detected, which included 6 aldehydes, 12 ketones, 8 each of fatty acids, alcohols and lactones, 4 each of esters and hydrocarbons or other compounds, and 12 compounds remained unidentified.

Identification of a synthetic cannabinoid 5F-NPB-22 (indazole analog 5F-PB-22) by gas chromatography/mass spectrometry (GC/MS) method

2016 ◽  
Vol 293 ◽  
pp. 56-67
Author(s):  
Robert Bachliński ◽  
◽  
Agnieszka Mroczek ◽  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Direct Injection ◽  
Ion Source ◽  
Synthetic Cannabinoid ◽  
Gas Chromatography Mass Spectrometry ◽  
Extraction Solvent ◽  
Chromatography Mass Spectrometry ◽  
Selection Of

This article presents the problem of transesterification of a synthetic cannabinoid 5F-NPB-22 and other structurally related indazole and indole-based compounds, such as NPB-22, 5F-PB-22, BB-22 and PB-22, caused by methanol – a solvent commonly applied in gas chromatography/mass spectrometry (GC/MS) analysis. The above process can result in drawing incorrect conclusions about the composition of analyzed product, due to the formation of ester compounds, which mainly affects the reliability of results. In the present study, in addition to the mixture of methanol and toluene, as well toluene alone was used to evaluate the effect of both these solvents on the results obtained with GC/MS. The quality of analyses was additionally confirmed by quadrupole-time-of-flight (Q-TOF) mass spectrometry with direct injection of sample into the ion source. The final results indicate that in the case of transesterification-sensitive compounds, the selection of an adequate extraction-solvent is of major importance. It is recommended to use toluene and exclude transesterification-supporting solvents such as low molecular weight alcohols (methanol.ethanol). Moreover, a prompt analysis of the extracted substances should be ensured in order to eliminate their potential esterification.

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