Para Red (PR) and Sudan dyes have been illegally used as colorants to adulterate certain foods by enhancing their red/orange colour. In addition, they are toxic and carcinogenic. This work presents the development of a simple flow injection chromatographic method combined with chemometric tools to perform the determination of PR, Sudan I (SI) and Sudan II (SII) in food samples. The flow chromatographic system consisted of a low-pressure manifold coupled to a reverse phase monolithic column. A Partial Least Square (PLS) model was applied to resolve overlapped absorption spectra registered for each dye at the corresponding retention time. The relative errors of calibration (RMSECV, %) were 0.49, 0.85 and 0.23, and the relative errors of prediction (RMSEP, %) were 1.12, 0.75 and 0.33 for PR, SI and SII, respectively. The residual predictive deviation (RPD) values obtained were higher than 3.00 for all analytes. The method was successfully applied to quantify the dyes in six different commercial spices samples. The results were compared with the HPLC reference method concluding that there were no significant differences at the studied confidence level (α = 0.05). The proposed method can be used to rapidly determine the analytes in a simple, reliable, low-cost and environmentally-friendly manner.Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05299-8.

• Publikační typ
• časopisecké články MeSH

Apples are known to be a rich source of phenolic compounds, however detailed studies about their content in the individual parts of apple trees are reported rarely. For this purpose, we tested various stationary phases for the determination of phenolic compounds in leaves, bark, and buds. Phloridzin, phloretin, chlorogenic acid, rutin, and quercitrin were analyzed with high performance liquid chromatography coupled with diode array detection. A YMC Triart C18-ExRS 150 × 4.6 mm, 5 μm particle size analytical column with multilayered particle technology was used. The separation was performed with a mobile phase that consisted of acetonitrile and 0.1% phosphoric acid, according to the gradient program, at a flow rate of 1 mL/min for 12.50 min. The concentration of phenolic compounds from 13 cultivars was in the range of 64.89-106.01 mg/g of dry weight (DW) in leaves, 70.81-113.18 mg/g DW in bark, and 100.68-139.61 mg/g DW in buds. Phloridzin was a major compound. The total antioxidant activity was measured using flow analysis and the correlation with the total amount of phenolic compounds was found. This finding can lead to the re-use of apple tree material to isolate substances that can be utilized in the food, pharmaceutical, or cosmetics industries.

• Publikační typ
• časopisecké články MeSH

Nově navržený hybridní biodegradabilní nanokompozitní porézní implantát (HBNPI) modifikovaný biogenním polyfosfátem (bio-polyP) představuje velmi dobrou možnost jak vytvořit kostní fúzi. Zvláště efektivní využití se nabízí v páteřní problematice, kde při jejím poranění či degenerativním postižení je často využívána metoda tzv. intervertebrální dézy. Námi navržený resorbovatelný HBNPI složený z vnějšího tvrdého keramického prstence a vnitřní měkké kolagen/nanohydroxyapatitové pěny v kombinaci s bio-polyP kopíruje osteokonduktivní a osteoinduktivní vlastnosti dosud užívaných autologních kostních štěpů. Syntetický HBNPI je připravován laboratorně a tím odpadají komplikace spojené s odběrem autoštěpů, eventuálně i riziko přenosu infektu v případě užití aloštěpu. Tento projekt se zaměřuje na in-vivo testování schopnosti HBNPI vytvořit intevertebrální dézu na zvířecím modelu a provést histologické a ex-vivo biomechanické porovnání s dosud užívanými autoštěpy. Výsledky budou tvořit podklad k vytvoření nové a bezpečnější metodiky intervertebrální dézy a umožní následné klinické testování.; Newly designed hybrid biodegradable nanocomposite porous implant (HBNPI) modified with biogenic polyphosphate (bio-polyP) represents a very good opportunity to create bone fusion. Particularly effective utilization seems to be in spinal problems ,where the method of intervertebral fusion is mainly applied in injuries or degenerative spinal diseases. Our designed resorbable HBNPI composed of a hard ceramic outer ring and the inner soft collagen/nanohydroxyapatit foam modified with bio-polyP copy osteoconductive and osteoinductive properties of currently used autologous bone grafts. Synthetic HBNPI is prepared in laboratory manner eliminating both the complications associated with autografts collection and possibly the risk of infection transmission in the case of allografts. This project is focused on in-vivo testing of HBNPI ability to create intervertebral fusion in animal model and compare histology and ex-vivo bimechanics with standard autograft method. Results will create base of new and safer method of intervertebral fusion allowing subsequent clinical testing.

• MeSH
• fúze páteře metody   MeSH
• implantace protézy MeSH
• lidé MeSH
• modely u zvířat MeSH
• nanokompozity terapeutické užití   MeSH
• páteř chirurgie   MeSH
• polyfosfáty terapeutické užití   MeSH
• prasata MeSH
• testování materiálů MeSH
• vstřebatelné implantáty MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• hodnotící studie MeSH

• Konspekt
• Ortopedie. Chirurgie. Oftalmologie
• NLK Obory
• ortopedie
• technika lékařská, zdravotnický materiál a protetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Glycoproteomics is a challenging branch of proteomics because of the micro- and macro-heterogeneity of protein glycosylation. Hydrophilic interaction liquid chromatography (HILIC) is an advantageous alternative to reversed-phase chromatography for intact glycopeptide separation prior to their identification by mass spectrometry. Nowadays, several HILIC columns differing in used chemistries are commercially available. However, there is a lack of comparative studies assessing their performance, and thus providing guidance for the selection of an adequate stationary phase for different glycoproteomics applications. Here, we compare three HILIC columns recently developed by Advanced Chromatography Technologies (ACE)- with unfunctionalized (HILIC-A), polyhydroxy functionalized (HILIC-N), and aminopropyl functionalized (HILIC-B) silica- with a C18 reversed-phase column in the separation of human immunoglobulin G glycopeptides. HILIC-A and HILIC-B exhibit mixed-mode separation combining hydrophilic and ion-exchange interactions for analyte retention. Expectably, reversed-phase mode successfully separated clusters of immunoglobulin G1 and immunoglobulin G2 glycopeptides, which differ in amino acid sequence, but was not able to adequately separate different glycoforms of the same peptide. All ACE HILIC columns showed higher separation power for different glycoforms, and we show that each column separates a different group of glycopeptides more effectively than the others. Moreover, HILIC-A and HILIC-N columns separated the isobaric A2G1F1 glycopeptides of immunoglobulin G, and thus showed the potential for the elucidation of the structure of isomeric glycoforms. Furthermore, the possible retention mechanism for the HILIC columns is discussed on the basis of the determined chromatographic parameters.

• MeSH
• chromatografie iontoměničová metody   MeSH
• chromatografie s reverzní fází metody   MeSH
• glykopeptidy izolace a purifikace   MeSH
• hydrofobní a hydrofilní interakce MeSH
• imunoglobulin G izolace a purifikace   MeSH
• isomerie MeSH
• lidé MeSH
• proteomika MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Effect of physicochemical properties including dissociation constant (pKa) and partition coefficient (log P) of the compounds on their extraction efficiency in sample preparation using fibrous polymer sorbents has been demonstrated. Poly-ε-caprolactone as meltblown/electrospun composite fibers, and polypropylene, polyethylene, poly(3-hydroxybutyrate), poly(lactic acid), and polyamide 6 in the meltblown fiber format were used as sorbents in solid-phase extraction. In addition, the polycaprolactone fibers were coated with dopamine, dopamine combined with heparin, and tannin, respectively, to modify their extraction properties. These fibers that were not yet used for extractions and the unique combination of sorbents and analytes significantly extends the scope of nanofibrous extraction. The extraction efficiency was determined using model pharmaceuticals including acetylsalicylic acid, moxonidine, metoprolol, propranolol, propafenone, diltiazem, atorvastatin, and amiodarone. These model compounds displayed the widest differences in both pKa and log P values. The extraction efficiency of some of the fibers reached 96.64%. Coating of polycaprolactone fibers with dopamine significantly improved extraction efficiency of slightly retained metoprolol while moxonidine was not retained on any sorbent. The fibrous sorbents were also tested for extraction of pharmaceuticals in bovine serum albumin and human serum, respectively, to demonstrate their capability to extract them from a complex protein-containing matrix. The clean-up efficiency of our fibers was compared with that of a commercial restricted access media (RAM) C-18 alkyl-diol silica column. Our technique is in accordance with the requirements of modern sample preparation techniques.

• MeSH
• extrakce na pevné fázi MeSH
• lidé MeSH
• nanovlákna * MeSH
• polymery MeSH
• proteiny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Due to specific physical properties, hydrodynamic cavitation (HC) is assigned to the powerful technologies for treating the biotic contamination in water including cyanobacteria. Contaminated water stream (CWS) can be cavitated directly by passing through some HC device, or indirectly when high-pressure jet stream (HPJS) is directed against its flow. Relatively small HPJS stream can thus treat a big volume of CWS in a short time or even work in continuous mode. Cyanobacteria floating in the CWS are forced to flow through the mixing cavitation zone. Within 2 h after single HC treatment, cyanobacterial cell suspensions showed disintegration of larger colonies and enhanced biomass sedimentation. Additional pre-treatment of CWS with low amounts of hydrogen peroxide (H2O2; 33, 66 and 99 μmol/L) enhanced the effect of HC and led to further inhibition of cyanobacterial photosynthesis (maximum quantum yield of photosystem II decreased by up to 60%). The number of cyanobacterial cells in the treated CWS decreased continuously over 48 and 72 h, though some cells remained alive and were able to recover photosynthetic activity. The technique proposed (direction of a HPJS against a CWS and pre-treatment with low H2O2 concentrations) provides (i) effective removal of cells from the water column, and (ii) reduced contamination by organic compounds released from the cells (especially cyanotoxins) as the cell membranes are not destroyed and the cells remain alive. This process shows potential as an effective pre-treatment step in water purification processes related to cyanobacterial contamination.

• MeSH
• čištění vody * MeSH
• hydrodynamika MeSH
• organické látky MeSH
• peroxid vodíku MeSH
• sinice * MeSH
• Publikační typ
• časopisecké články MeSH

In the past two decades, supercritical fluid chromatography has evolved from a niche application to a comprehensive technology and a fully-fledged alternative to conventional high-performance liquid chromatography. In this study, we have focused on chiral separation of synthetic cathinones in gradient supercritical fluid chromatography coupled to mass spectrometry using an inverse gradient of a make-up solvent. Synthetic cathinones possess an amphetamine-like effect and, therefore, are frequently being offered on the Internet as a replacement for illicit drugs. Cathinones are chiral compounds, however, they are usually marketed and used as racemic mixtures. Since the effect of individual enantiomers can significantly vary, there is a need for the development of enantioseparation methods enabling to study the biological effects of individual enantiomers. Since cathinones are basic molecules, they are easily protonated (positively charged) under weakly acidic mobile phase conditions, which is a typical feature of supercritical mobile phases with an alcohol as an organic modifier. The positively charged species represent ideal analytes for ion exchangers, such as chiral zwitterion ion exchangers Chiralpak ZWIX (+) and Chiralpak ZWIX (-), which possess a positively and negatively charged unit in the molecular structure of the selectors. The presence of the positive charge in the selector's structure, functioning as a counter-ion for the positively charged analytes, significantly reduces the required amount of a buffer, which is plausible for hyphenation of such a separation system with mass spectrometry. For mass spectrometry hyphenated to supercritical fluid chromatography, the use of a make-up solvent is required to avoid analyte precipitation when using a low concentration of an organic co-solvent (modifier) in the super-/subcritical mobile phase. Hereby, we introduce a unique approach, which is based on the gradient introduction of the make-up to the post-column effluent. Using this approach, it is possible to keep constant the overall amount of the organic solvent (modifier and make-up) introduced into the mass spectrometer when using a gradient of the organic modifier. We show that the developed gradient elution method facilitates the chiral separation of all employed analytes, while the mobile-phase gradient compensation by the inverse make-up gradient enables their detection with high signal intensities.

• MeSH
• alkaloidy chemická syntéza   chemie   izolace a purifikace   MeSH
• hmotnostní spektrometrie metody   MeSH
• reologie * MeSH
• rozpouštědla chemie   MeSH
• stereoizomerie MeSH
• superkritická fluidní chromatografie metody   MeSH
• teplota MeSH
• tlak MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH

Extensive information is available on total arsenic in particulate matter (PM), but little is known about the relative contribution of each individual species. Recent studies often focus on inorganic arsenic as arsenite and arsenate, neglecting the organoarsenicals, i.e., methylarsine, dimethylarsine, and trimethylarsine or the corresponding oxidized forms methylarsonate, dimethylarsinate, and trimethylarsine oxide, although they were already first detected in PM in the mid-1970s. This work presents results from more than 300 daily PM10 and further size-resolved atmospheric PM samples in the size range from 15 nm to 10 μm collected in an urban environment in Austria during the course of a year. An ion-exchange-HPLC (with anion and cation exchange columns) and an ICPMS/MS system were used to study the seasonal variations of total arsenic and all species known to exist in PM. Inorganic arsenic was present in significant amounts in all samples with highest concentrations during winter, but also all organoarsenicals were detected throughout the year. We show that their contribution cannot be ignored, as particles smaller than <1 μm can contain up to 35% of the water+H2O2 extractable arsenic as methylated species, but only dimethylarsinate showed a clear seasonal trend throughout the year.

• MeSH
• arsen analýza   MeSH
• peroxid vodíku MeSH
• pevné částice MeSH
• roční období MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rakousko MeSH

Colloid deposition in granular media is relevant to numerous environmental problems. Classic filtration models assume a homogeneous pore space and largely ignore colloid aggregation. However, substantial evidence exists on the ubiquity of aggregation within porous media, suggesting that deposition is enhanced by it. This work studies the deposition process in relation to aggregate size and structure. We demonstrate that aggregation is induced at typical groundwater velocities by comparing the repulsive DLVO force between particle pairs to the hydrodynamic shear force opposing it. Column experiments imaged with high-resolution X-ray computed tomography are used to measure aggregate structure and describe their morphology probability distribution and spatial distribution. Aggregate volume and surface area are found to be power-law distributed, while Feret diameter is exponentially distributed with some flow rate dependencies caused by erosion and restructuring by the fluid shear. Furthermore, size and shape of aggregates are heterogeneous in depth, where a small number of large aggregates control the concentration versus depth profile shape. The range of aggregate fractal dimensions found (2.22-2.42) implies a high potential for restructuring or breaking during transport. Shear-induced aggregation is not currently considered in macroscopic models for particle filtration, yet is critical to consider in the processes that control deposition.

• MeSH
• filtrace * MeSH
• fraktály MeSH
• koloidy * MeSH
• poréznost MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The foul odour of cheese-production wastewater is a common problem in areas surrounding dairy wastewater treatment plants. For successful odour management, a better understanding of the key odorants and how to handle them during wastewater treatment is needed. This paper documents the results of using gas chromatography-mass spectrometry coupled with olfactometry (GC-MS/O) to analyze odours emanating from a possibly overloaded treatment plant in Czechia. Using a DB5 capillary column, 20 compounds were detected and identified, nonanal (FDgeomean 152) and octen-3-ol (FDgeomean 2048) having the most pungent odours.

• MeSH
• odoranty * analýza   MeSH
• odpadní voda MeSH
• olfaktometrie MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• sýr * analýza   MeSH
• Publikační typ
• časopisecké články MeSH