Michal P. Dybowski

Modified application of HS-SPME for quality evaluation of essential oil plant materials.

The main limitation in the standard application of head space analysis employing solid phase microextraction (HS-SPME) for the evaluation of plants as sources of essential oils (EOs) are different quantitative relations of EO components from those obtained by direct analysis of EO which was got in the steam distillation (SD) process from the same plant (EO/SD). The results presented in the paper for thyme, mint, sage, basil, savory, and marjoram prove that the quantitative relations of EO components established by HS-SPME procedure and direct analysis of EO/SD are similar when the plant material in the HS-SPME process is replaced by its suspension in oil of the same physicochemical character as that of SPME fiber coating. The observed differences in the thyme EO composition estimated by both procedures are insignificant (F(exp)<F(crit)). In relation to classical EO analysis involving the SD procedure, the application of the new HS-SPME procedure proposed in this paper substantially shortens the evaluation time of plant material quality and thus may improve the efficiency of analytical laboratories.

SPE isolation of low-molecular oxygen compounds from essential oils

Analytical procedures of complex mixtures frequently involve their initial pre-fractionation to make the analysis easier or possible. Recently, SPE is frequently applied for this purpose. This article discusses the possibility of essential oils fractionation using SPE with octadecyl modified silica. The presented results show that developed SPE with C-18 sorbent allows for easy and total isolation (100% recovery) of low-molecular oxygen compounds from the remaining compounds, for which the recovery exceeds 95%. The obtained recoveries are satisfactory for preliminary separation of essential oils for analytical and preparative purposes.

The determination of α- and β-thujone in human serum – Simple analysis of absinthe congener substance

Absinthe is a strong spirit beverage, mostly green in color, containing besides ethyl alcohol (main component), alcoholic macerate of wormwood and other plants such as star anise and fennel seed. Due to the potential risks associated with the presence of α- and β-thujone many countries have implemented strict rules limiting the content of these congeners in alcohol products. The presented paper describes a simple and sensitive method for the determination of α- and β-thujone in human serum using Solid Phase Extraction as a sample preparation method combined with GC/MS analysis. The procedure involves the protein precipitation process, which generally degrades the protein-analyte complex, and SPE isolation of thujone from the examined materials. The described method is characterized by a low LOD and a very high recovery of the analytes. The present method for the estimation of α- and β-thujone concentration in human fluids after the consumption of alcoholic beverages and other foods containing the substance is applicable in forensic and clinical toxicology because of its simplicity and rapidness with high sensitivity.

Determination of myristicin in commonly spices applying SPE/GC.

The increasing use of myristicin (a component of nutmeg) as a cheap hallucinogenic intoxicant requires from the world of science the elaboration of new methods for determination of this compound in daily-use foodstuffs. The present study describes a fast, simple and sensitive method of myristicin analysis in nutmeg and spices containing it using gas chromatography combined with ultrasonic solvent extraction and solid phase extraction processes. The developed method is characterized by high recovery (almost 100%), a low detection limit 1.35 ng g(-1) and good repeatability (average RDS value equal 2.39%). The presented analytical approach constitutes a substantial improvement on previously reported methods for myristicin analysis and seems to be the method of choice for determining the amount of the compound in spices containing nutmeg.

Simple SPE–GC method for anethole determination in human serum

Recently, much attention has been given to congener analysis, which can be used to check the possibility of postoffence drinking claims in forensic toxicology. In this type of analysis, the information given by the defendant regarding the type, quantity, and time of consumption of a specific alcoholic beverage is used to calculate theoretically expected congener concentration in the blood and this is compared with the analytically determined concentrations in the blood sample. Many alcoholic drinks aromatized with essential oils of plants and fruits contain a specific congener, for example, anethole in aniseed drinks. The present study describes the GC procedure of anethole analysis in human plasma using SPE as the sample preparation method. The procedure involves the protein precipitation process, which generally degrades the protein-analyte complex, and SPE isolation of anethole from the examined materials. This analytical approach is proposed as a method of choice for the estimation of anethole concentration in human fluids after the consumption of alcoholic beverages and other foods containing the substance. The described method is characterized by a low LOD (8.33 ng/g) and a very high recovery (average recovery 98.37%) of the analyte.

Application of the QuEChERS procedure for analysis of Δ9-tetrahydrocannabinol and its metabolites in authentic whole blood samples by GC–MS/MS

PurposeAnalysis of drugs and their metabolites in biofluids usually demands the application of sample preparation methods that allow for full isolation of analyzed substances from the matrix. The purpose of this study was to develop a method using the QuEChERS procedure for analysis of Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC).MethodsTHC, 11-OH-THC and 11-COOH-THC were quantified in whole blood samples using QuEChERS extraction and gas chromatography–tandem mass spectrometry.ResultsThe described method is characterized by good linearity, very low detection limits and satisfactory inter- and intraday precisions for THC, 11-OH-THC and 11-COOH-THC. The applicability of the procedure was confirmed using authentic whole blood samples collected from 30 persons suspected of driving under the influence of drugs.ConclusionsThe application of QuEChERS extraction described herein is a simple and convenient method for the routine analysis of THC, 11-OH-THC and 11-COOH-THC in whole blood samples from living and deceased humans. To our knowledge, this paper is the first academic report describing the QuEChERS extraction of THC and its metabolites from whole blood specimens.