Comparison of six derivatizing agents for the determination of nine synthetic cathinones using gas chromatography-mass spectrometry

Six acylation reagents have been compared for their derivatisation potential towards nine synthetic cathinones by gas chromatography-mass spectrometry (GC-MS). The evaluated reagents were pentafluoropropionic anhydride (PFPA), trifluoroacetic anhydride (TFA), chlorodifluoroacetic anhydride (CLF2AA), heptafluorobutyric anhydride (HFBA), acetic anhydride (AA) and propionic anhydride (PA). The synthetic cathinones included flephedrone (4-fluoromethcathinone or 4-FMC), mephedrone (4-methylmethcathinone or 4-MMC), pentedrone (also known as α-methylamino-valerophenone), methedrone (4-methoxy-N-methcathinone, p-methoxymethcathinone), methylone (3,4-methylenedioxy-N-methylcathinone or bk-MDMA), butylone (β-keto-N-methylbenzodioxolylbutanamine or bk-MBDB), ethylone (3,4-methylenedioxy-N-ethylcathinone MDEC or bk-MDEA), pyrovalerone (4-methyl-β-keto-prolintane) and 3,4-methylenedioxypyrovalerone (MDPV). The derivatizing agents were optimised for incubation time and temperature with some important validation parameters studied to evaluate derivatisation reactions. The anhydrides studied proved to be suitable for synthetic cathinones – all of them showing RSD and accuracy below 20%. PFPA and HFBA followed by TFA are the best choice of derivatising agents based on validation parameters. Five internal standards were evaluated with good results. Three way ANOVA, interference, fragmentation patterns and high peak area values at a concentration of 0.50 μg ml−1 were evaluated and discussed. AA and PA derivatives give high relative abundance for most drugs examined. HFBA gives more ions and multi-fragmentation patterns

Chemical derivatization processes applied to amine determination in samples of different matrix composition

No abstract available

Chiral and Achiral Analysis of Benzodiazepine and Anti-Anginal Drugs in Forensic Toxicology

The study in this thesis has three main parts important to the subject of modern forensic toxicology. The first is the extraction and chromatographic separation of nifedipine and its metabolites from whole blood, the second is an evaluation of a beta-cyclodextrin high performance liquid chromatography column and the third is the chiral analysis of temazepam enantiomers from human plasma samples

Impact of selected parameters of the fermentation process of wine and wine itself on the biogenic amines content: Evaluation by application of chemometric tools

The demand for safer foods has promoted more research into biogenic amines (BAs) over the past few years, however, there are still some questions that remain unanswered. Despite the fact that BAs are present in wine and can cause toxic effect to the body, a shared regulation limiting the amounts of BAs in wine is still lacking. A detailed understanding of their presence in wine is also important for the food trade sector. Therefore, the aim of this work was to determine the level of selected BAs in wine samples origin from Poland. Thereafter, the evaluation of correlation between concentration of BAs and selected parameters including pH, alcohol content and fermentation temperature by application of chemometric analysis was carried out. The BAs were determined by application of previously developed SPME-GC–MS methodology characterized by low detection limits ranged from 0.009 μg/L (tyramine) to 0.155 μg/L (histamine). Data obtained in this study show that none of the wine samples surpassed the toxic levels reported for BAs in the literature (the total BAs content was ranged from 7 to 2174 μg/L), therefore, these wines appear to be safe as regards the risk associated with the intake of potentially toxic BAs. Moreover, several correlations between occurrence, concentration of biogenic amines, important factors of winemaking process as well as physico-chemical parameters of wine were indicated. Even though information on BAs is currently not included in wine composition databases, information on their existence, distribution, concentration and knowledge of existing relationships between BAs and other wine parameters is crucial and may be useful for the food industry, health professionals and consumers

Anti-Inflammatory Effects of Metformin Irrespective of Diabetes Status

Rationale: The diabetes drug metformin is under investigation in cardiovascular disease but the molecular mechanisms underlying possible benefits are poorly understood. Objective: Here we have studied anti-inflammatory effects of the drug and their relationship to anti-hyperglycaemic properties. Methods and Results: In primary hepatocytes from healthy animals, metformin and the IKKβ inhibitor BI605906 both inhibited TNFα-dependent IκB degradation and expression of pro-inflammatory mediators IL-6, IL-1b, and CXCL1/2. Metformin suppressed IKKα/β activation, an effect which could be separated from some metabolic actions, in that BI605906 did not mimic effects of metformin on lipogenic gene expression, glucose production and AMPK activation. Equally AMPK was not required either for mitochondrial suppression of IκB degradation. Consistent with discrete anti-inflammatory actions, in macrophages metformin specifically blunted secretion of pro-inflammatory cytokines, without inhibiting M1/M2 differentiation or activation. In a large treatment naïve diabetes population cohort, we observed differences in the systemic inflammation marker, Neutrophil to Lymphocyte Ratio (NLR), following incident treatment with either metformin or sulfonylurea monotherapy. Compared to sulfonylurea exposure, metformin reduced the mean log-transformed NLR after 8-16 months by 0.09 units (95% CI=0.02-0.17, p=0.013), and increased the likelihood that NLR would be lower than baseline after 8-16 months (OR 1.83, 95% CI=1.22-2.75, p=0.00364). Following up these findings in a double blind placebo controlled trial in nondiabetic heart failure (trial registration: NCT00473876), metformin suppressed plasma cytokines including the ageing-associated cytokine CCL11. Conclusions: We conclude that anti-inflammatory properties of metformin are exerted irrespective of diabetes status. This may accelerate investigation of drug utility in non-diabetic cardiovascular disease groups

Direct solid phase microextraction combined with gas chromatography – mass spectrometry for the determination of biogenic amines in wine

A direct method based on immersion solid phase microextraction (DI-SPME) gas chromatography mass-spectrometry (GC-MS) was optimized and validated for the determination of 16 biogenic amines in Polish wines. In the analysis two internal standards were used: 1,7-diaminoheptane and bis-3-aminopropylamine. The method allows for simultaneous extraction and derivatization, providing a simple and fast mode of extraction and enrichment. Different parameters which affect the extraction procedure were studied and optimized including ionic strength (0–25%), fiber materials (PDMS/DVB, PDMS/DVD+OC, Polyacrylate, Carboxen/PDMS and DVB/CAR/PDMS) and timings of the extraction, derivatization and desorption processes. Validation studies confirmed the linearity, sensitivity, precision and accuracy of the method. The method was successfully applied to the analysis of 44 wine samples originating from several regions of Poland and 3 wine samples from other countries. Analysis showed that many of the samples contained all examined biogenic amines. The method, assessed using an Eco-Scale tool with satisfactory results, was found to be green in terms of hazardous chemicals and solvents usage, energy consumption and production of waste. Therefore the proposed method can be safely used in the wine industry for routine analysis of BAs in wine samples with a minimal detrimental impact on human health and the environment

Literature update of analytical methods for biogenic amines determination in food and beverages

Biogenic amines (BAs) have been reported in a variety of foods, such as fish, meat, cheese, and wines. The formation of BAs in food by the microbial decarboxylation of amino acids can result in human allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Control measures to prevent biogenic amine formation in foods and/or reduce their levels should be considered. Therefore, monitoring of BAs in food samples with the application of analytical techniques is of high importance. This review is based on literature data from 2010 until today and refers to food samples and alcoholic beverages. The rationale of this study is to provide data for the occurrence of BAs in food and beverages samples and a comparison of the analytical techniques and challenges in liquid and solid matrices. Importantly, BAs can be used as future markers for quality and freshness of the food products and alcoholic beverages

Application of molecularly imprinted polymers in an analytical chiral separation and analysis

Over the last two decades the process of development and application of a new types of molecular imprinted polymer (MIP) sorbents in the field of analytical chemistry have been widely described in the literature. One of the new trends in analytical chemistry practice is the use of new types of MIP sorbents as specific sorption materials constituting the stationary phase in advanced separation techniques. The following review paper contains comprehensive information about the application of a specific and well defined MIP sorbents (with the data base in the paper about the reagents used in MIP preparation process) as stationary phases in separation techniques including high performance liquid chromatography and capillary electrochromatography. Coverage includes newly created types of stationary phases (MIP sorbents) used for chiral recognition, with the focus on applications in enantioselective separation

First-Principles Study on Ligand Binding and Positional Disorder in Pentlandite

Density functional theory, in conjunction with a cluster expansion model, has been used to study the structure and stability of the positionally disordered iron–nickel sulfide mineral pentlandite (Pn), (Fe,Ni)₉S₈, with results indicating heterogeneous nearest neighbor metal contacts are more energetically favorable than homogeneous contacts. The virtual crystal approximation was also explored as a means to address positional disorder, but while reliable results could be obtained for the bulk model, the same was not true for the surface, as local distortions which affected the surface model energies could not be reproduced. We also address the binding of ethyl xanthate (CH₃CH₂OCS₂^–), water, and hydroxide to the [111] Pn surface to understand the mode of action of industrial xanthate flotation agents better. In order to model anionic ligands bound to a periodic boundary condition surface we propose applying a correction derived from the surface work function to remove the additional charge introduced by the ligand. The results obtained from the ligand binding studies indicate that while ethyl xanthate could readily displace up to a full monolayer of water per unit cell it is likely that Fe-enriched surfaces will bind xanthate in competition with the hydroxide anion, while a Ni-enriched surface will preferentially bind hydroxide anions over xanthate