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9 result(s) for "LC-Q-Orbitrap MS/MS"
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Study on the Mass Spectrometry Fragmentation Patterns for Rapid Screening and Structure Identification of Ketamine Analogues in Illicit Powders
Ketamine analogues have been emerging in recent years and are causing severe health and social problems worldwide. Ketamine analogues use 2-phenyl-2-aminocyclohexanone as the basic structure and achieve physiological reactions similar to or even more robust than the prototype of ketamine by changing the substituents on the benzene ring (R1 and R2) and amine group (RN1). Therefore, the mass spectrometry (MS) fragmentation pathways and fragments of ketamine analogues have certain regularity. Eight ketamine analogues are systematically investigated by GC-QTOF/MS and LC-Q-Orbitrap MS/MS with the positive mode of electrospray ionization. The MS fragmentation patterns of ketamine analogues are summarized according to high-resolution MS data. The α-cleavage of carbon bond C1-C2 in the cyclohexanone moiety and further losses of CO, methyl radical, ethyl radical and propyl radical are the characteristic fragmentation pathways of ketamine analogues in EI-MS mode. The loss of H2O or the sequential loss of RN1NH2, CO and C4H6 are the distinctive fragmentation pathways of ketamine analogues in ESI-MS/MS mode. Moreover, these MS fragmentation patterns are first introduced for the rapid screening of ketamine analogues in suspicious powder. Furthermore, the structure of the ketamine analogue in suspicious powder is 2-(Methylamino)-2-(o-tolyl)cyclohexan-1-one, which is further confirmed by NMR. This study contributes to the identification of the chemical structure of ketamine analogues, which can be used for the rapid screening of ketamine analogues in seized chemicals.
Development and Validation of LC–MS/MS and LC-Q-Orbitrap/MS Methods for Determination of Glyphosate in Vaccines
We developed and validated a simple and an accurate method for determination and quantification of glyphosate residue in vaccines. Vaccines were centrifuged in the first step of sample preparation to eliminate matrix effects. The sample was washed with a mixture of dichloromethane and chloroform, and was directly analysed without derivatisation. The extract was injected into a liquid chromatography tandem mass spectrometry (LC–MS/MS) system and liquid chromatography quadrupole-orbitrap mass spectrometry (LC-Q-Orbitrap/MS) with a Hypercarb column. The methods were validated through a series of assessments including specificity, limit of detection (LOD), limit of quantification (LOQ), linearity, precision and accuracy, recovery, and stability. In LC–MS/MS, LOD and LOQ of glyphosate in DPT and pneumococcal vaccines were 0.078 and 0.258 ng mL−1, whereas MMR was 0.156 and 0.515 ng mL−1. In Q-Orbitrap/MS, LOD and LOQ of glyphosate in DPT and pneumococcal vaccines were 2.425 and 8.803 ng mL−1, whereas MMR was 4.850 and 16.166 ng mL−1. The linear correlation coefficients (r2) were higher than 0.999. Relative standard deviation (RSD) was 0.9–11.7% for both intra-day and inter-day precisions. Accuracy was evaluated to be in the range of 86.3–110.4% both for intra-day and for inter-day. Mean recoveries of three different fortification levels were within 93.1–108.3% for DPT and pneumococcal vaccines and 71.1–73.4% for MMR vaccine. The RSD of stability of spiked samples was within 8%.
In Vitro Anti-Tumor and Hypoglycemic Effects of Total Flavonoids from Willow Buds
Salix babylonica L. is a species of willow tree that is widely cultivated worldwide as an ornamental plant, but its medicinal resources have not yet been reasonably developed or utilized. Herein, we extracted and purified the total flavonoids from willow buds (PTFW) for component analysis in order to evaluate their in vitro anti-tumor and hypoglycemic activities. Through Q-Orbitrap LC-MS/MS analysis, a total of 10 flavonoid compounds were identified (including flavones, flavan-3-ols, and flavonols). The inhibitory effects of PTFW on the proliferation of cervical cancer HeLa cells, colon cancer HT-29 cells, and breast cancer MCF7 cells were evaluated using an MTT assay. Moreover, the hypoglycemic activity of PTFW was determined by investigating the inhibitory effects of PTFW on α-amylase and α-glucosidase. The results indicated that PTFW significantly suppressed the proliferation of HeLa cells, HT-29 cells, and MCF7 cells, with IC50 values of 1.432, 0.3476, and 2.297 mg/mL, respectively. PTFW, at different concentrations, had certain inhibitory effects on α-amylase and α-glucosidase, with IC50 values of 2.94 mg/mL and 1.87 mg/mL, respectively. In conclusion, PTFW at different doses exhibits anti-proliferation effects on all three types of cancer cells, particularly on HT-29 cells, and also shows significant hypoglycemic effects. Willow buds have the potential to be used in functional food and pharmaceutical industries.
A comprehensive investigation on the chemical changes of traditional Chinese medicine with classic processing technology: Polygonum multiflorum under nine cycles of steaming and sunning as a case study
The processing of traditional Chinese medicine (TCM) plays an important role in the clinical application, which usually has the function of \"increasing efficiency and reducing toxicity\". Polygonum multiflorum (PM) has been reported to induce hepatotoxicity, while it is believed that the toxicity is reduced after processing. Studies have shown that the hepatotoxicity of PM is closely related to the changes in chemical components before and after processing. However, there is no comprehensive investigation on the chemical changes of PM during the processing progress. In this research, we established a comprehensive method to profile both small molecule compounds and polysaccharides from raw and different processed PM samples. In detail, an online two-dimensional liquid chromatography coupled with quadrupole-orbitrap mass spectrometry (2D-LC/Q-Orbitrap MS) was utilized to investigate the small molecules, and a total of 150 compounds were characterized successfully. After multivariate statistical analysis, 49 differential compounds between raw and processed products were screened out. Furthermore, an accurate and comprehensive method for quantification of differential compounds in PM samples was established based on ultra-high performance liquid chromatography/Q-Orbitrap-MS (UHPLC/Q-Orbitrap-MS) within 16 min. In addition, the changes of polysaccharides in different PM samples were analyzed, and it was found that the addition of black beans and steaming times would affect the content and composition of polysaccharides in PM significantly. Our work provided a reference basis for revealing the scientific connotation of the processing technology and increasing the quality control and safety of PM.
Analysis of Fatty Acid in Biological Samples Using Liquid Chromatography–Quadrupole-Orbitrap Mass Spectrometry Under Parallel Reaction Monitoring Mode
Fatty acids (FAs) are an important class of functional small molecules and participate in a variety of life biological processes. This experiment proposed a liquid chromatography–quadrupole-Qrbitrap mass spectrometry (LC–Q-Orbitrap MS) method to perform FA profiling under parallel reaction monitoring (PRM) acquisition mode. The FA was derivatized by 2-dimethylaminoethylamine (DMED) to increase the ionization efficiency and provide the characterized fragment pattern. The mass spectra obtained from full scan, multiple ion monitoring (MIM), and PRM were compared. The results showed that the protonated ion of FA + DMED–H 2 O was detected and the neutral loss of 45.06 Da was observed in the tandem mass spectrum. The PRM method provided the highest selectivity and sensitivity for FA detection with the help of accurate mass weight and specific neutral loss-based fragments. The method validation was performed using the FA standards and pooled quality control serum sample, which showed that the established method had good repeatability, stability, and linearity. Finally, the developed method was successfully applied to analyze the rat serum and brain tissue samples for the drug efficacy evaluation of gross saponin of Tribulus terrestris L. fruit (GSTTF) against middle cerebral artery occlusion (MCAO)-induced ischemic stroke. This method has extensive practicability and great potential in the detection of FA, especially for the analysis of samples with complex matrices.
Systematic quality evaluation of Peiyuan Tongnao capsule by offline two-dimensional liquid chromatography/quadrupole-Orbitrap mass spectrometry and adjusted parallel reaction monitoring of quality markers
Peiyuan Tongnao capsule (PTC) is a prescription medicine of traditional Chinese medicine with the effects of “nourishing the kidney,” “replenishing essence,” “extinguishing wind,” and “opening the meridian”. PTC is also widely used in clinic for the treatment of stroke and chronic cerebral circulation insufficiency. However, the quality control studies of PTC are hitherto quite limited. Here, we aim to fully utilize an advanced chromatography–mass spectrometry hyphenation technique to qualitatively and quantitatively evaluate the quality of PTC. Firstly, a two-dimensional liquid chromatography/quadrupole-Orbitrap mass spectrometry (2D-LC/Q-Orbitrap-MS) approach was established for multicomponent characterization. An offline 2D-LC system fitted with an Xbridge Amide column and an HSS T3 column showed an orthogonality of 0.63 and a theoretical peak capacity of 6930. Eleven fractions of PTC, after hydrophilic interaction chromatography (first dimension), were further analyzed by reversed-phase ultrahigh-performance liquid chromatography/Q-Orbitrap-MS (UHPLC/Q-Orbitrap-MS, second dimension) using a rapid negative/positive switching mode. Consequently, 178 compounds were separated, 96 of which were identified or tentatively characterized. Secondly, co-condition fingerprint analysis of seven constituted herbal medicines of PTC was performed to unveil ten active ingredients (citric acid, rehmannioside D, echinacoside, paeoniflorin, verbascoside, liquiritin, 2,3,5,4′-tetrahydroxystilbene-2-O-β-d-glucoside, cinnamic aldehyde, glycyrrhizic acid, and emodin) as the quality markers of PTC. Thirdly, a UHPLC/PRMad (adjusted parallel reaction monitoring) method was established and validated to quantify the ten marker compounds in 14 batches of PTC. To the best of our knowledge, this is the first study to report comprehensive multicomponent characterization, authentication, and quality evaluation of PTC, which could be used to lay the foundation for quality control, biological efficacy research, and further development.
LC–MS analysis of polar and highly polar organic pollutants in Barcelona urban groundwater using orthogonal LC separation modes
Groundwater samples may contain thousands of organic pollutants from infiltration of surface water, sewer leakages, and to a minor extent from public water supply network losses. Polar (0 < log D  <  − 2.0) and very polar substances (log D  <  − 2.0) have been largely beyond the scope of applied analytical methodologies in environmental monitoring because of challenges related to their extraction from the sample and subsequent chromatographic separation. In this study, we developed an analytical workflow for 96 pollutants covering a broad polarity range, including pharmaceuticals, industrial chemicals, and artificial sweeteners, potentially seeping through the soil in urban areas. The Besos aquifer located at the Northern-eastern edge of the city of Barcelona was chosen as a study area due to the deterioration of the quality of the aquifers over the past years and the proven presence of numerous pollutants. The methodology consisted of vacuum-assisted evaporation (VAE) followed by chromatographic separation of the sample on two columns with orthogonal retention mechanisms, namely, an HSS T3 column (modified C18) and a BEH amide column (HILIC). The analytes were detected by high-resolution mass spectrometry on a Q Exactive Orbitrap system in data-independent acquisition mode. Taking into consideration the retention as well as the peak shape, a Quality Score (QS) was assigned for each analyte to evaluate the quality of each chromatographic peak of each compound. While 67 compounds, including 19 polar and 48 moderately polar, were satisfactorily retained on an HSS T3, 29 compounds, including 14 highly polar, 14 polar, and one moderately polar, were analyzed in the BEH amide column. The optimized methodology was applied for the analysis of 89 out of 96 validated contaminants with satisfactory recoveries in samples collected from seven wells, providing low LODs (0.02 to 0.45 ng L −1 ) and LOQs (0.06 to 1.34 ng L −1 ). A number of highly polar and polar compounds not previously reported to occur in GW, including artificial sweeteners, pharmaceuticals, and industrial chemicals, were detected at concentrations as high as few$$\\mu$$μ g L −1 .
Efficacy of the Aqueous Extract of Azadirachta indica Against the Marine Parasitic Leech and Its Phytochemical Profiling
Zeylanicobdella arugamensis (Hirudinea), a marine parasitic leech, not only resulted in the mortality of the host fish (Groupers) but also caused economic losses. The current study aimed to elucidate the antiparasitic efficacy of the aqueous extract of the Azadirachta indica leaves against Z. arugamensis and to profile the composition via LC-Q Exactive HF Orbitrap mass spectrometry. Different concentrations (25, 50 and 100 mg/mL) of A. indica extract were prepared and tested on the parasitic leeches. The total mortality of leeches was noticed with an exposure to the A. indica aqueous extract. The average times required for the aqueous extract at concentrations of 25, 50 and 100 mg/mL to kill the leeches were 42.65 ± 9.20, 11.69 ± 1.11 and 6.45 ± 0.45 min, respectively, in a dose-dependent manner. The Orbitrap mass spectrometry analysis indicated the presence of five flavonoids (myricetin 3-O-galactoside, trifolin, isorhamnetin, quercetin and kaempferol), four aromatics (4-methoxy benzaldehyde, scopoletin, indole-3-acrylic acid and 2,4-quinolinediol), three phenolics (p-coumaric acid, ferulic acid and phloretin) and two terpenoids (pulegone and caryophyllene oxide). Thus, our study indicates that A. indica aqueous extract is a good source of metabolites with the potential to act as a biocontrol agent against the marine parasitic leech in aquaculture.
An Innovative Olive Pâté with Nutraceutical Properties
Food plays a central role in health, especially through consumption of plant-derived foods. Functional foods, supplements, and nutraceuticals are increasingly entering the market to respond to consumer demand for healthy products. They are foods, supplements, and ingredients which offer health benefits beyond the standard nutritional value. Some benefits are associated with phenolic compounds and phytochemicals with antioxidant properties. An olive pâté (OP) was added with antioxidants derived from olive mill wastewater (OMWW) to obtain a functional product rich in phenolic compounds. The olive pâté is produced from the ground olive pericarp, which shows an excellent natural antioxidant content. The OMWW is a waste product from oil processing, which is also rich in phenolic compounds. The result was a product rich in trans-resveratrol, OH tyrosol, and tyrosol in concentrations such as satisfying the European community’s claims regarding the possible antioxidant action on plasma lipids with excellent shelf-life stability. The total phenolic content was assayed by a colorimetric method, the antioxidant activity by the ABTS [(2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] test, the phenolic profile by Q Exactive Orbitrap LC-MS/MS. The shelf-life stability was confirmed by yeast, molds, and total microbial count, pH, and water activity determinations, and the best pasteurization parameters were determined. The palatability was judged as excellent.