The pungency of chili peppers, the most popular hot spice used worldwide, is caused by capsaicinoids (CPDs), the content of which can vary greatly due to varietal differences and growing conditions. For the first time, a novel simple method for the fast determination of CPDs in chili peppers and chili products was developed based on adsorptive transfer cyclic square-wave voltammetry (AdTCSWV), using adsorption of lipophilic CPDs on an unmodified glassy carbon electrode surface from methanolic extracts of chili pepper samples. The CSWV is based on short oxidation of adsorbed CPDs to quinoid products, and their subsequent reduction and re-oxidation to provide specific analytical signals with a linear range from 0.
View Article and Find Full Text PDFWall paintings are integral to cultural heritage and offer rich insights into historical and religious beliefs. There exist various wall painting techniques that pose challenges in binder and pigment identification, especially in the case of egg/oil-based binders. GC-MS identification of lipidic binders relies routinely on parameters like the ratios of fatty acids within the plaster.
View Article and Find Full Text PDFA novel, cheap and easy-to-construct device and a simple method for partition coefficient determination in liposome/water system based on modified equilibrium dialysis have been developed. The device consists of two vials separated by a semi-permeable membrane, through which the free form of a low molecular weight substance is transported by shaking assisted diffusion. Five test substances, eugenol, carvacrol, thymol, 4-hydroxybenzyl alcohol (4-HBA) and butylparaben were analyzed after equilibration in aqueous phase by three methods, HPLC-UV, GC-MS and DPV with comparable results.
View Article and Find Full Text PDFSpecialty coffees from various geographical origins were processed using different extraction methods. Four extraction techniques were employed: cold brew (CB), espresso (ES), French press (FR), and aeropress (AE). The potential health benefits of coffee brews were linked to their antioxidant activity, as determined by the DPPH assay, and total polyphenol content (TPC) measured through the Folin-Ciocalteu reducing-capacity assay.
View Article and Find Full Text PDFDetermination of cholesterol in food matrices is essential for quality control concerning the health of consumers. Herein, a simple electrochemical approach for cholesterol quantitation in dairy products is evaluated. The newly developed differential pulse voltammetric method using acetonitrile-perchloric acid mixture as a supporting electrolyte is statistically compared to GC-MS and HPLC-UV.
View Article and Find Full Text PDFElectronically driven micromanipulation (EDM) with microscopic control was used as a novel tool for sample preparation prior to direct (matrix assisted) laser desorption/ionization mass spectrometric ((MA)LDI-MS) analysis of mature pea seed coat composition in defined layers. Microscissors were used for seed coat fragment shape adjustment, microtweezers for sample holding and "microjackhammer" Milling Pro for precise mechanical removing of cell layers in defined depths (2, 5 or 10 μm). These procedures circumvent the application of embedding media or enzymatic digestion of seed coat that would complicate mass spectra interpretation (presence of matrix signals, analyte signals enhancement or attenuation) and represent alternative for 3D metabolites profiling.
View Article and Find Full Text PDFThe efficiency of desorption/ionization becomes more critical as the sampled surface area decreases. Desorption electrospray and desorption nanoelectrospray belong to ambient ionizations and enable direct surface analysis including mass spectrometric imaging. Lateral resolution in tens of micrometers was demonstrated for desorption nanoelectrospray previously, but sensitivity of the surface scan can be an issue.
View Article and Find Full Text PDFThe authors would like to call the reader's attention to the following correction in the section "Semiquantitative analysis", page 1176, of the original publication.
View Article and Find Full Text PDFMasking derivatization was introduced for the determination of residual solvents in samples containing a volatile reactive matrix component(s). Isobutylboronic acid, used in the last step of Bortezomib synthesis, represents a compound passing to the gas phase and deteriorating a chromatographic column during a headspace analysis. The masking derivatization with 1,8-diaminonaphthalene allowed a simple and straightforward conversion of isobutylboronic acid to a stable nonvolatile derivative and thus prevented gas chromatography column deterioration.
View Article and Find Full Text PDFAtmospheric solids analysis probe mass spectrometry (ASAP-MS) was used for the first time for direct surface analysis of plant material. It can be readily used for surface analysis of whole and intact pea seeds and their seed coats, and for the study of the profile of fatty acids on the outer surface. Furthermore, ASAP-MS in combination with multivariate statistics allowed classification of pea genotypes with respect to physical dormancy and investigation of related biological markers.
View Article and Find Full Text PDFIn this study, a soil from two ceramic vessels belonging to Corded Ware culture, 2707⁻2571 B.C., found in a cremation grave discovered in Central Moravia, Czech Republic, was analyzed using matrix-assisted laser desorption/ionization⁻mass spectrometry (MALDI⁻MS) combined with advanced statistical treatment (principal component analysis, PCA, and orthogonal projection to latent structures discriminant analysis, OPLS-DA) and by enzyme-linked immunosorbent assay (ELISA).
View Article and Find Full Text PDFA carbon fiber brush electrode (CFBE) was newly designed and used as a substrate for both controlled potential electrolysis and atmospheric solids analysis probe (ASAP) mass spectrometry. Electropolymerized and strongly adsorbed products of electrolysis were directly desorbed and ionized from the electrode surface. Electrochemical properties of the electrode investigated by cyclic voltammetry revealed large electroactive surface area (23 ± 3 cm) at 1.
View Article and Find Full Text PDFA microscale discontinuous fermenter was used for anaerobic digestion of wine waste - a hardly gasifiable feedstock material. Efficiency of biogas production, i.e.
View Article and Find Full Text PDFEspresso coffee samples prepared at various roasting degrees defined according to its basic conventional classification (light, medium, medium-dark and dark roasted) were analyzed by ultra-performance liquid chromatography/tandem mass spectrometry. Obtained raw data were processed using multivariate statistical analysis (Principal Component Analysis, PCA) to evaluate chemical differences between each roasting degrees (untargeted part of study). All four roasting degrees were resolved in appropriate Score plot.
View Article and Find Full Text PDFPolar-ionic and hydro-organic mobile phase mode of high-performance liquid chromatographic separations of 23 sterically constrained primary β(3)-amino acid enantiomers containing, alkyl, aryl or heteroaryl side-chains were carried out by using newly developed Cinchona alkaloid-based zwitterionic chiral selectors and the stationary phases Chiralpak ZWIX(+)™ and ZWIX(-)™. In the polar-ionic mode, the effects of the composition of the bulk solvent and the natures of the co- and counter-ions, while in the hydro-organic mode, the effects of the pH, the counter-ion concentration and the structures of the analytes were investigated. The separations of the enantiomers of these 23 primary β(3)-amino acids, which can be classified as a series of quasi- (pseudo-) homologs, were optimized in both chromatographic modes.
View Article and Find Full Text PDFHigh-performance liquid chromatography plays an important role in analysis of historical organic colorants. A number of papers have been published in this field over the last 30 years. Classification of the most commonly used natural dyes and an overview of high-performance liquid chromatography methods with main focus on recent works (2008 to the beginning of 2014) are provided.
View Article and Find Full Text PDFDerivatives of quinoxalin-2-one are interesting compounds with potential pharmacological activity. From this point of view, understanding of their electrochemical behavior is of great importance. In the present paper, a mechanism of electrochemical reduction of quinoxalin-2-one derivatives at mercury dropping electrode was proposed.
View Article and Find Full Text PDFScientificWorldJournal
September 2012
The performances of ionic liquid (1-hexyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide, IL/CPE) and iron phthalocyanine (IP/CPE) modified carbon paste electrodes in electroanalytical determinations of rutin were evaluated and compared to the performance of unmodified carbon paste electrode (CPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), differential pulse adsorptive stripping voltammetry (DPAdSV), and amperometry were used for rutin analysis. The best current responses of rutin were obtained at pH 4.
View Article and Find Full Text PDFHyphenation of micro-liquid and ultra-performance liquid chromatography with a hybrid (QqTOF) tandem mass spectrometry was studied from the viewpoint of their applicability for monitoring of anthocyanin dyes in various cultivars and different vintages of red wine. After appropriate optimization both techniques proved to be suitable for this task. UHPLC system provided lower LOD and LOQ values as well as higher productivity and precision of retention parameters and peak areas with respect to micro-LC method.
View Article and Find Full Text PDFA novel long drop time mercury electrode has been constructed from common fused-silica capillary (50 μm I.D., 360 μm E.
View Article and Find Full Text PDFAn analytical protocol for the isolation and quantification of indole-3-acetic acid (IAA) and its amino acid conjugates was developed. IAA is an important phytohormone and formation of its conjugates plays a crucial role in regulating IAA levels in plants. The developed protocol combines a highly specific immunoaffinity extraction with a sensitive and selective LC-MS/MS analysis.
View Article and Find Full Text PDFN,N-dialkylaminoethane-2-thiols belong to the group of precursors and degradation products of chemical warfare agents (CWAs). These compounds were analyzed by means of electrospray ionization-multiple stage mass spectrometry (ion trap) and proposed fragments were confirmed by accurate mass measurement using a QqTOF system. The fragmentation pathways of studied compounds and the products of oxidation (formation of -S-S- linkage) were described.
View Article and Find Full Text PDFThe development of a rapid, simple and accurate analytical method aimed at the detection and quantification of bovine milk in either ovine or caprine milk samples by means of CE-MS analyses of whey proteins with high-ionic strength and presence of acidic running buffer is described. The high-ionic strength buffer was used in order to minimize the problems with the adsorption of the proteins onto the fused-silica capillary wall. The acidic running electrolyte, pH 1.
View Article and Find Full Text PDFSelected precursors and degradation products of chemical warfare agents namely N,N-dialkylaminoethane-2-ols, N,N-dialkylaminoethyl-2-chlorides and some of related N-quaternary salts were studied by means of electrospray ionization-multiple tandem mass spectrometry (ESI-MS(n)). Proposed structures were confirmed with accurate mass measurement. General fragmentation patterns of these compounds are discussed in detail and suggested processes are confirmed using deuterated standards.
View Article and Find Full Text PDFChemical warfare agents and their degradation products represent a broad group of compounds with different chemical properties (polarity, volatility, thermostability, etc.). These chemicals often have to be detected and determined in complex matrices and therefore highly efficient separation techniques hyphenated to selective and sensitive detectors play an indispensable role.
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