Currently for compound detection the most difficult are sampling steps and sample preparation for analysis of highly volatile compounds (VOC) and their derivatives, such as ethylene, propylene, ...acetaldehyde and acetone. For this purpose single- and multibed sorbent tubes were prepared, filled with the following materials: Tenax TA, Carbotrap, Carbopack C, Carbosieve SIII, Carboxen 569. The linear relationship between the mass of analysed compounds and decreased recovery from carbon molecular sieve was determined. The highest desorption recovery (∼100%) for C
2
-C
5
hydrocarbons from multibed sorption traps contained Tenax TA/Carbotrap/Carbosieve SIII. Sorbent traps were also used to determine selected VOC (acetone, acetaldehyde, 2-butanone, benzene, toluene, m,p-xylene) in gas phase of tobacco smoke from single 1R5F reference cigarette. Quantitative analysis of selected compounds was done by standard addition method with r
2
= 0.9931 for 2-butanone and 0.9773 for acetaldehyde. The best combination of sorbent materials included Tenax TA/Carbotrap/Carboxen 569 allowing for VOC determination at low level: 0.31 µg L
−1
for m,p-xylene and 40.24 µg L
−1
for acetaldehyde. This composition of multibed sorption trap also gave the highest recovery for acetone and 2-butanone as well as the lowest RSD (9.81%, and 9.14%, respectively).
•EC-MS approach was applied for generation of potential metabolites produced from selected immunosuppressant drugs.•EC-MS is an analytical tool to simulate phase I and II metabolism for the target ...compounds.•EC-MS was revealed to be a suitable tool to procure a feasible analytical base for the envisioned in vivo experiments.
Electrochemistry (EC) coupled with liquid chromatography and tandem mass spectrometry (HPLC/ESI-MS/MS) was used to study the oxidation products of cyclosporine A (CYC), everolimus (EWE), mycophenolic acid (MFA), sirolimus (SIR) and tacrolimus (TAK). Mimicry of the oxidative phase I and II metabolism was achieved in a thin-layer cell equipped with a boron doped diamond (BDD) working electrode. Structures of the electrochemically generated products were elucidated on the basis of MS/MS experiments. Additionally, a sensitive, specific and rapid HPLC-MS/MS method has been developed and validated for the quantification of selected drugs and their metabolites in human serum. Sample preparation was accomplished through microextraction by packed sorbent (MEPS) process. Finally, the identification of electrochemical products was done and results were compared with known metabolites of studied immunosuppressant drugs. Electrochemical conversion of target compounds has appeared as a new pseudo-in vitro instrumental technology for the prediction of potential metabolites, since the oxidation products have also been identified in serum samples.
The pH role in benzoic acid derivatives chromatographic analysis were under the current study. The retention factor (k), as well as the peak asymmetry (f
AS
), were determined and compared using five ...commercially available reversed phase columns. Utilization of statistical approaches of tested chromatographic columns were divided into several groups according to the obtained data (retention factor, asymmetry) due to the different mobile phases pH (pH=5.8 and 3.0). Although four studied columns (Purospher-STAR, Alltima, Reprosil, Symmetry) were the octadecyl type, they showed significant differences in the benzoic acids derivatives. Obtained results allowed for distinctions in individual column chromatographic behavior explanation.
In recent years, there has been a growing interest in the therapeutic potential of natural compounds, particularly of plant origin, owing to their demonstrated anti-inflammatory properties. Among ...these, Anacardium occidentale, commonly known as cashew, has garnered significant attention due to its reputed health benefits. This study aim to establish a correlation between the bioactive compounds contained in the extracts of Anacardium occidentale and its anti-inflammatory activity. Dried Anacardium occidentale leaves powder was used as the extraction matrix. Extraction techniques are maceration, pressurized fluid extraction (PFE), and supercritical fluid extraction (SFE). The preliminary analysis of extracts was made by LC-MS/MS. The Response Surface Methodology (RSM), Principal Component Analysis (PCA), and heat maps were employed to model the influence of experimental conditions on extraction yield and peak area of specific compounds from the plant. To evaluate anti-inflammatory activity, RAW 264.7 cells were cultured, activated with LPS, and treated with varying concentrations of the plant extracts. Cell proliferation was assessed using the XTT assay. Indeed, Anacardium occidentale extracts contain anacardic acids, cardanols, and cardol, with distinct profiles yielded by SFE and ethanol-based methods. RSM shows that temperature and ethanol, as additives to CO
, significantly affect extraction efficiency in both PFE and SFE. Moreover, this composition with SFE demonstrate higher selectivity for specific group of compounds. The extracts exhibit anti-inflammatory properties without cytotoxicity in macrophages, reducing levels of pro-inflammatory proteins COX-2, COX-1, and TLR4 in activated cells. This suggests their potential as anti-inflammatory agents without adverse effects on cell viability or pro-inflammatory protein levels in non-activated cells. Overall, these findings underscore the promising therapeutic potential of Anacardium occidentale extracts in mitigating inflammation, while also providing crucial insights into optimizing the extraction process for targeted compound isolation. Thus, this makes a good prospect for the development of anti-inflammatory drugs from this plant.
Ultra high-performance corrected liquid chromatography has been used for the separation and analysis of unmodified and modified antisense oligonucleotides. For this reason, we tested various columns ...of low particle sizes in our analysis of unmodified and phosphorothioate oligonucleotides. The influence of both the type and concentration of ion-pair reagent on the retention of the studied biomolecules was tested. The developed methods were used for separation of unmodified oligonucleotides and to determine antisense oligonucleotides in human serum samples. The results proved that octadecyl and phenyl columns are the most selective in the resolution of oligonucleotides which differ in the position of single nucleotides in the sequence. The phenyl column was selected and applied for the analysis of phosphorothioate oligonucleotides in serum samples. The calibration plots showed good linearity within the test concentration ranges. The intra-day CV of the calibration curve slopes was in the range of 1.6 to 4.2 %. The limits of detection (LODs) were in the range of 0.11-0.16 μg mL(-1), while the limit of quantification (LOQ) values were between 0.35 and 0.51 μg mL(-1).
The method of determination of 4-biphenylamine (4-BA) in workplace air using SPE and HPLC has been presented. The method consists in passing the air that contains 4-BA through a glass fiber filter ...with sulfuric acid placed on it, washing out the substance settled on the filter, using water and a solution of sodium hydroxide, solid phase extraction (SPE) in order to enrich the analyte, replace the dissolvent with methanol, and analyze the obtained solution using a method of highly efficient liquid chromatography with fluorescent detection (λ
ex
= 268 nm, λ
em
= 389 nm). Measuring range for the 100 dm
3
air sample was: 0.1-2 μg/m
3
. Limit of detection (LOD) and limit of quantification (LOQ) were 0.18 ng/m
3
and 0.54 ng/m
3
, respectively.
Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a ...promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet.
In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance – linezolid, daptomycin, and moxifloxacin – from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system.
The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively.
The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.
ABSTRACT
Ethanol metabolism is accompanied by generation of free radicals that damage cell components, especially lipids. The present study was designed to investigate the efficacy of the preventive ...effect of black tea on the lipid oxidative modifications in different tissues (plasma, liver, brain, kidney, stomach, lung, intestine, and spleen) of 12-month-old rats chronically intoxicated with ethanol. Ethanol intoxication caused changes in the level/activity of antioxidants that led to the significant increase in the level of lipid oxidative modification products. Oxidative modifications were estimated by measuring lipid hydroperoxides, malondialdehyde, and 4-hydroxynonenal by high-performance liquid chromatography (HPLC) and by spectrophotometric determination of conjugated dienes. These lipid-modification marker levels were increased in almost all examined tissues (3%-71%) after ethanol intoxication. Described changes were in accordance with the liver level of the most often used marker of arachidonic acid oxidation, isoprostane (8-isoPGF2α), determined by the LC/MS system. Administration of black tea to ethanol-intoxicated rats remarkably prevents the significant increase (by about 15%-42%) in concentrations of all measured parameters regarding all examined tissues, but especially the plasma, liver, brain, stomach, and spleen. The preventive effect of black tea in the other organs (kidney, lung, intestine) caused a decrease in examined markers in a smaller degree (by about 7%-28%). To determine in the liver the major constituents of black tea mainly responsible for antioxidative action such as catechins and theaflavins, which were absorbed in organism, the present study indicates their protective effect against ethanol-induced oxidative modifications of lipids.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper describes sorption and transport phenomena of selected heavy metals (e.g., Pb, Zn, Ni and Cu) in the superficial layer of soil and sewage sludge compost. The main aim of the study was the ...investigation of possibility of heavy metals contamination in soil profile reclaimed by sewage sludge compost. The column leaching test as well as the sequential Tessier extraction procedure were applied to investigate the mitigation of heavy metals. The results revealed that distribution of metals in specific Tessier fractions was the major factor influencing their transport in the investigated soils profiles. Moreover, sorption capacity of the soil sample studied was substantially greater to prevent transportation of metals into the lower horizons and groundwater.
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