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.

Development, validation, and certification by isotope dilution gas chromatography-mass spectrometry of lyophilized human serum reference materials for cortisol (CRM 192 and 193) and progesterone (CRM 347 and 348)

1991 ◽  
Vol 37 (4) ◽  
pp. 540-546 ◽  
Author(s):  
Linda Thienpont ◽  
Lothar Siekmann ◽  
Alexander Lawson ◽  
Elisabeth Colinet ◽  
Andrȳ De Leenheer
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Reference Materials ◽  
Isotope Dilution ◽  
Certified Reference Materials ◽  
Collaborative Study ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Coefficients Of Variation

Abstract The Community Bureau of Reference of the European Communities has produced four batches of lyophilized serum Certified Reference Materials, two for cortisol (CRM 192 and 193) and two for progesterone (CRM 347 and 348). For cortisol, one of the pools consisted of serum from healthy blood donors, whereas the second batch was supplemented with pure cortisol. The progesterone Reference Materials contained only endogenous hormone concentrations. Assessment of vial-to-vial variability in the cortisol and progesterone concentrations showed no between-sample inhomogeneity, and the materials were stable. The quality of the materials was therefore considered sufficient for certification of the values for the cortisol and progesterone concentrations by a collaborative study involving several laboratories from the European Communities, using isotope dilution gas chromatography-mass spectrometry. Inaccuracy in reconstitution of the lyophilized materials was less than 0.3%; imprecision of sampling was less than 0.2%. For determinations of cortisol and progesterone concentrations, the mean within-laboratory coefficients of variation (CVs) were 1.76% (CRM 192), 1.19% (CRM 193), 1.64% (CRM 347), and 1.75% (CRM 348). The between-laboratory CVs were greater: CRM 192, 1.79%; CRM 193, 1.48%; CRM 347, 2.08%; and CRM 348, 2.16%. The concentrations in the reconstituted Reference Materials were certified to be 273 nmol/L in CRM 192 and 763 nmol/L in CRM 193 for cortisol and 10.13 nmol/L in CRM 347 and 40.3 nmol/L in CRM 348 for progesterone. Uncertainties at the 0.95 confidence level--6 (CRM 192), 14 (CRM 193), 0.21 (CRM 347), and 1.0 nmol/L (CRM 348)--were considered compatible with the intended use of the materials.

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.

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