scholarly journals Adsorption of Phenol and Chlorophenols by HDTMA Modified Halloysite Nanotubes

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3309
Author(s):  
Piotr Słomkiewicz ◽  
Beata Szczepanik ◽  
Marianna Czaplicka
Keyword(s):  
Liquid Chromatography ◽  
Structural Changes ◽  
Halloysite Nanotubes ◽  
Breakthrough Curves ◽  
Infrared Spectrometry ◽  
Hexadecyltrimethylammonium Bromide ◽  
Adsorption Model ◽  
Adsorption Parameters ◽  
Adsorption Method ◽  
Chromatography Method

The adsorption of phenol, 2-, 3-, 4-chlorophenol, 2-, 4-dichlorophenol and 2-, 4-, 6-trichloro-phenol on halloysite nanotubes modified with hexadecyltrimethylammonium bromide (HDTMA/halloysite nanocomposite) was investigated in this work by inverse liquid chromatography methods. Morphological and structural changes of the HDTMA/halloysite nanocomposite were characterized by scanning and transmission electron microscopy (SEM, TEM), Fourier-transform infrared spectrometry (FT-IR) and the low-temperature nitrogen adsorption method. Specific surface energy heterogeneity profiles and acid base properties of halloysite and HDTMA/halloysite nanocomposite have been determined with the inverse gas chromatography method. Inverse liquid chromatography methods: the Peak Division and the Breakthrough Curves Methods were used in adsorption experiments to determine adsorption parameters. The obtained experimental adsorption data were well represented by the Langmuir multi-center adsorption model.

scholarly journals Synthesis and Characterization of Halloysite/Carbon Nanocomposites for Enhanced NSAIDs Adsorption from Water

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3754 ◽  
Author(s):  
Beata Szczepanik ◽  
Nina Rędzia ◽  
Laura Frydel ◽  
Piotr Słomkiewicz ◽  
Anna Kołbus ◽  
...  
Keyword(s):  
Density Functional ◽  
Structural Changes ◽  
Adsorption Mechanism ◽  
Nitrogen Adsorption ◽  
Infrared Spectrometry ◽  
Adsorption Model ◽  
Adsorption Method ◽  
Carbon Nanocomposites ◽  
Chemical Structures ◽  
Intra Particle Diffusion

The adsorption of ketoprofen, naproxen, and diclofenac (non-steroidal anti-inflammatory drugs, NSAIDs) on halloysite/carbon nanocomposites and non-modified halloysite were investigated in this work. Halloysite/carbon nanocomposites were obtained through liquid phase impregnation and carbonization using halloysite as the template and saccharose as the carbon precursor. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and low-temperature nitrogen adsorption method were employed to study the morphological and structural changes of the halloysite/carbon nanocomposites. The effects of contact time, initial concentration of adsorbates, pH of solution, and mass of adsorbent on the adsorption were studied. Adsorption mechanism was found to fit pseudo-second-order and intra-particle diffusion models. The obtained experimental adsorption data were well represented by the Langmuir multi-center adsorption model. Adsorption ability of halloysite/carbon nanocomposites was much higher for all the studied NSAIDs in comparison to non-modified halloysite. Optimized chemical structures of ketoprofen, naproxen, and diclofenac obtained by Density Functional Theory (DFT) calculation showed that charge distributions of these adsorbate molecules and their ions can be helpful to explain the details of adsorption mechanism of NSAIDs on halloysite/carbon nanocomposites.

Development and Validation of A Reversed Phase-High Performance Liquid Chromatography Method for the Quantitative Estimation of Ramipril Drug Content from Formulated Dosage Form

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Raju Chandra ◽  
Manisha Pant ◽  
Harchan Singh ◽  
Deepak Kumar ◽  
Ashwani Sanghi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Active Ingredient ◽  
High Performance ◽  
Limit Of Detection ◽  
Quantitative Estimation ◽  
Reversed Phase ◽  
Uv Detector ◽  
Chromatography Method ◽  
Drug Content

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.

Developing a High-performance Liquid Chromatography Method for Simultaneous Determination of Loratadine and its Metabolite Desloratadine in Human Plasma

2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
High Performance ◽  
Allergic Diseases ◽  
Reversed Phase ◽  
Hplc Method ◽  
H1 Receptor ◽  
Chromatography Method

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.

scholarly journals Analytical Methods for Quantification and Identification of Intact Glucosinolates in Arabidopsis Roots Using LC-QqQ(LIT)-MS/MS

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Kourosh Hooshmand ◽  
Inge S. Fomsgaard
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Crude Extract ◽  
Matrix Effects ◽  
Critical Role ◽  
Reversed Phase ◽  
Biologically Active ◽  
Natural Soil ◽  
Chromatography Method ◽  
Arabidopsis Root

Glucosinolates are biologically active secondary metabolites in Brassicaceae plants that play a critical role in positive and negative interactions between plants and root-associated microbial communities. The aim of this study was to develop a reversed-phase liquid chromatography method to quantify and identify intact glucosinolates in the root of Arabidopsis thaliana (Arabidopsis) grown in non-sterile natural soil by using liquid chromatography-hybrid triple quadruple-linear ion trap (LC-QqQ(LIT)) mass spectrometry. The Synergi Fusion C18-based column was found to be effective for sufficient retention and separation of nine intact glucosinolates without the need for time-consuming desulfation or ion-pairing steps. Method validation results showed satisfactory inter-day and intra-day precision for all glucosinolates except for 4-hydroxyglucobrassicin. Good inter-day and intra-day accuracy and recovery results were observed for glucoiberin, gluconapin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrassicin. However, for 4-hydroxyglucobrassicin, glucoraphanin and glucoerucin corrections to quantification results might be necessary since the recovery and accuracy results were not optimal. Matrix effects were shown to have a negligible effect on the ionization of all target analytes. The established liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was applied to quantify target intact glucosinolates in Arabidopsis root crude extract of four different wild-type accessions where differences in terms of concentration and composition of intact glucosinolates were observed. Employment of sensitive and selective precursor ion survey scan of m/z 97 in combination with the information-dependent acquisition (IDA) of the enhanced product ion (EPI) dependent scan (Prec97-IDA-EPI) using LC-QqQ(LIT) provided high confidence in structural characterization of diverse intact glucosinolate profiles in complex Arabidopsis root crude extract.

Profiling and Quantification of the Key Phytochemicals from the Drumstick Tree (Moringa oleifera) and Dietary Supplements by UHPLC-PDA-MS

Planta Medica ◽  
2020 ◽  
Author(s):  
Omer I. Fantoukh ◽  
Yan-Hong Wang ◽  
Abidah Parveen ◽  
Mohammed F. Hawwal ◽  
Gadah A. Al-Hamoud ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Dietary Supplements ◽  
High Performance ◽  
Moringa Oleifera ◽  
Negative Ion ◽  
Array Detector ◽  
Ionization Mass ◽  
Fractionation Process ◽  
Chromatography Method ◽  
Drumstick Tree

Abstract Moringa oleifera is known as a drumstick tree and is cultivated in the subtropics and tropics. It exhibits antihypertensive and antidiabetic effects. An ultra-high-performance liquid chromatography method was developed for the determination of 9 phytochemicals in M. oleifera leaves and marketed products. The efficient separation was achieved within 7 min with a temperature of 45 °C by using a C-18 column as the stationary phase and water/acetonitrile with 0.05% formic acid as the mobile phase. The method was validated for linearity, repeatability, limits of detection, and limits of quantification. The limits of detections of phenolic compounds 1 – 9 were as low as 0.2 µg/mL. The photodiode array detector at 220 and 255 nm wavelengths was recruited for quantification. The key phytochemicals were detected in the range of 0.42 to 2.57 mg/100 mg sample weight in 13 dietary supplements. This study considers the quantitative analysis for lignans in M. oleifera for the first time. Isoquercitrin (5) and quercetin 3-O-(6-O-malonyl)-β−D-glucopyranoside (6) predominates the leaves of M. oleifera with inherent degradable nature detected for compound 6. Niazirin (2) was detected in amounts between 0.010 – 0.049 mg/100 mg while compound 1 was undetectable and potentially an artifact because of the fractionation process. The characterization and confirmation of components were achieved by liquid chromatography-electrospray ionization-mass spectrometry with extractive ion monitoring for the positive and negative ion modes. The developed and validated method is robust and rapid in the conclusive quantification of phytochemicals and authentication of the Moringa samples for quality assurance.

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